title: Stephen Tompkinson

text: In 1994, he was Private Simon 'Spock' Matlock, a history teacher and intellectual in BBC comedy drama "All Quiet on the Preston Front", written by Tim Firth and set in Lancashire. Alistair McGowan replaced him after the first series because Tompkinson had other commitments. That same year he was in "Downwardly Mobile" – a Yorkshire Television sitcom about a group of Yuppies – aired for one season but failed to make an impression and was not recommissioned.


title: Stephen Tompkinson

text: From 1996 to 1998 he portrayed, in the popular "Ballykissangel", the struggles of a young English Roman Catholic priest assigned as curate to a church in Ireland's 'back of beyond'. In 1998 he starred as Jim Harper in the three-part ITV psychological thriller "Oktober", about a naive English teacher at a posh school in Switzerland. His character becomes a guinea pig in the trials of a new mind-altering drug. Tompkinson performed his own stunts. He says that "I grabbed this project because I'd never been asked to do anything like this before. And the chance to do stunts was one reason it was so appealing."


title: Stephen Tompkinson

text: Also in 1998, and again in 1999, he co-starred with Robson Green in two series of "Grafters", about two Geordie labourers who attempt to go into business together renovating an old London house owned by a pair of Yuppies. Tompkinson's performance was praised by James Rampton of "The Independent":


title: Stephen Tompkinson

text: It is Tompkinson who – despite having the less showy part – really catches the eye. In the shadow of a more successful brother and a domineering wife, he precisely captures an air of despondent, hen-pecked resignation. Like Eeyore, he seems to be pursued by his own personal raincloud. Nobody does defeated better. Tompkinson is an actor who's become a winner by playing the loser...Trevor can be added to the actor's growing gallery of characters whom viewers watch and think, 'I know that bloke.'


title: Stephen Tompkinson

text: Tompkinson and "Ballykissangel"'s Dervla Kirwan worked together again in 1999 on the TV version of Tim Firth's "The Flint Street Nativity". They also co-starred in the 2001 mini-series "Hereafter", which never aired in the UK but was released on DVD under the title "Shades" in the United States and Canada in 2012.


title: Stephen Tompkinson

text: In 2001, he co-starred with "Heartbeat" star Nick Berry in the mini-series "In Deep", as part of BBC1's Crime Doubles season. The promotional material described his performance as "Tompkinson as you have never seen him before" and a career "gamble". He agreed with that assessment: ""In Deep" is a very gritty drama and not the kind of thing that I'm normally associated with".


title: Stephen Tompkinson

text: Tompkinson and Claire Skinner appeared as a couple in Series 1 of the comedy "Bedtime", which aired August and September 2001. In 2002, he appeared as the character 'Ted' with co-star Dawn French in the comedy drama mini-series "Ted and Alice". The sitcom "Mr. Charity" (2001), which aired on BBC2, was panned by the critics, drew poor viewer ratings, and was axed after six episodes.


title: Stephen Tompkinson

text: In 2003, after a long delay, ITV aired the mini-series "Lucky Jim". Tompkinson had bought the rights to the Kingsley Amis novel, which had not been adapted for some time, with the intention of playing the central character. Jack Rosenthal did the screenplay. The cast included Keeley Hawes as his co-star and love interest Christine, Robert Hardy, Helen McCrory, Denis Lawson, Hermione Norris and Penelope Wilton. "The Guardian" praised it as "deftly adapted by Jack Rosenthal ... immaculately done, not least because of Stephen Tompkinson's performance as Jim, with stellar support from [the rest of the cast, especially] Helen McCrory." In December 2004, he appeared as Detective Inspector Slack in a new adaptation of Agatha Christie's "The Murder at the Vicarage".


title: Stephen Tompkinson

text: In 2004, Tompkinson played his first fact-based role in BBC1's two-part drama "In Denial of Murder", playing the character of the journalist Don Hale. There was controversy surrounding how the case was depicted, and in preparing to portray Don Hale he struggled to make sense of it. When asked his opinion, he explained that although he had done research to prepare for the role, he was merely an actor working from a script in which he had total faith and that he believed to be fair.


title: Stephen Tompkinson

text: In 2005, "Marian, Again" was a psychological drama about the horrors that could lie within any community and just beyond anyone's front door. Owen Teale co-starred, along with Kelly Harrison in the title role and Samantha Beckinsale.


title: Stephen Tompkinson

text: Of his role in "Prime Suspect", Tompkinson says "I had a call from my agent who told me they were to film the last-ever "Prime Suspect" with Helen Mirren. And I said, 'Yes!' before she could finish. She said, 'There is a part you might be interested in...' and I said, 'I meant "Yes, I'll do it," not "Yes, please continue!" I mean, here is a chance to work with one of the greatest actresses there is. Taking a part in the final "Prime Suspect" was the quickest decision I've ever made!"


title: Stephen Tompkinson

text: ITV drama series "Wild at Heart", created by Ashley Pharoah, began airing in the UK in January 2006 and ran for seven series. Tompkinson played Bristol veterinarian Danny Trevanion, who relocated with his family to South Africa where they attempted to build up a successful wildlife preserve and veterinary surgery. Tompkinson was also co-executive producer for 33 episodes and executive producer for one.


title: Stephen Tompkinson

text: In 2010 he was cast as Inspector Alan Banks in "DCI Banks: Aftermath", a two-part television pilot adaptation of one of Peter Robinson's crime novels. "DCI Banks: Aftermath" drew seven million viewers, beating BBC1's "Spooks" in the ratings battle for the same timeslot. On 14 June 2013, ITV announced that "DCI Banks" has been commissioned for a third six-part series. He played a role in the BBC series "Truckers" during the same year.


title: Stephen Tompkinson

text: Barely out of drama school, he appeared in 1988 (as Stephen Duffell) with Ken Goodwin and Freddie Davies in Peter Chelsom's 11-minute short film titled "Treacle". It was the tale of comedian Alfie Duffell's melodic legacy, set amid the Blackpool variety scene. The work received a 1988 BAFTA nomination in the category of Best Short Film.


title: Stephen Tompkinson

text: In 1996 he starred in a British-made international feature film, "Brassed Off", about a brass band in Grimley, a fictional Yorkshire colliery town where the mines are being shut down by the Tory government in the name of progress.


title: Stephen Tompkinson

text: In February 2012, he filmed his first lead role in a feature film titled "Harrigan", described on its 2013 release in Britain as having "a thin budget and cartoonish script".


title: Stephen Tompkinson

text: Tompkinson has said repeatedly that he enjoys the challenge of mixing television and film roles with live stage productions. He has appeared on stage in London's West End and in theatres across the UK. Of the 1992 production of Michael Wall's "Women Laughing" at the Royal Exchange Theatre, Alan Hulme of the "Manchester Evening News" described the cast as "superb...and the acting has the shocking eloquence of picture postcards in acid." And "The Independent" described "The End of the Food Chain" (1994) at the Stephen Joseph Theatre in Scarborough as "excellent" and "vividly acted."


title: Stephen Tompkinson

text: 2003 saw him starring as Mortimer Brewster, along with Michael Richards of "Seinfeld" fame, in "Arsenic and Old Lace" at The Strand Theatre in London. The part required him to deliver his lines in a New York drawl. One reviewer commented, "The fact that many American audience members...assumed that Stephen was a bone fide American confirms the authenticity of his twang."


title: Stephen Tompkinson

text: In 2007, he toured in "Charley's Aunt", playing the role of Donna Lucia D'Alvadorez. In a review in the British Theatre Guide Sheila Connor said:


title: Stephen Tompkinson

text: This is Stephen Tompkinson as you have never seen him before – hilarious even before he dons the frock. His manner, voice, expression and actions are spot-on...totally uproariously funny...It is at Babb's entrance that the play really takes off, Tompkinson revealing himself to be an inspired comic genius to add to his multitude of diverse credits...A truly entertainingly hilarious performance, and it is to be hoped that Tompkinson will treat us to more of the same.


title: Stephen Tompkinson

text: In 2008, he played the deeply sinister and complex lead character of Vindice in the Jacobean bloodbath "The Revenger's Tragedy" at the Royal Exchange Theatre in Manchester. He felt sympathy for the character and explained why the play appealed to him:


title: Stephen Tompkinson

text: He's not a villain, he's an anti-hero, really. You can see he has been wronged. The audience get to be voyeurs and enjoy watching him get his retribution. It's the black-and-white morality of the play, its bloodthirsty nature, that appealed to me. The way that things are dealt with, there was no red tape: it was out with the poison or the sword if you were wronged.


title: Stephen Tompkinson

text: In 2009, he toured in "Sign of the Times", playing the character of Frank Tollit, who has spent the past 25 years putting up letters on buildings but dreams of becoming a novelist. His colleague Alan (Tom Shaw), 30 years his junior, wants to be a rock star. Tompkinson said, "The play is a comedy but much more. It is about having dreams and ambition; it's about happiness and failure. Frank's good at his job; he does enjoy it, but he has bigger dreams. I think everyone will be able to relate to it."


title: Stephen Tompkinson

text: When Shaun Prendergast, who is a friend, wrote "Faith and Cold Reading" he created the part of a villain called Freddie the Suit for Tompkinson. The staging of that play at the Live Theatre in Newcastle in February–March 2011 is his most recent stage run.


title: Stephen Tompkinson

text: Tompkinson made his musical theatre debut in London's West End in the lead role of King Arthur in Monty Python's "Spamalot" at the Playhouse Theatre 20 November 2012.


title: Stephen Tompkinson

text: In 2018, he played Yvan in the UK tour of "Art", having previously played the role at the Wyndham's Theatre in London's West End in 2000.


title: Stephen Tompkinson

text: During the Christmas 2018 season he played Ebenezer Scrooge in Jack Thorne's new adaptation of "A Christmas Carol" at The Old Vic, London.


title: Stephen Tompkinson

text: In 2019 he is touring a production of Willy Russell's Educating Rita, co-starring with Jessica Johnson. This has been very well received by both critics and audiences.


title: Stephen Tompkinson

text: Tompkinson has hosted or narrated a number of other UK television programs, including a FIFA "100 Years of Football" documentary. In 1999, he presented the BBC2 documentary "Great Railway Journeys: Singapore to Bangkok," part of Series 4 of the popular "Great Railway Journeys" travel documentaries that aired over many years in the UK and on PBS in the U.S.


title: Stephen Tompkinson

text: In 2009, he took part in the documentary, "Stephen Tompkinson's Great African Balloon Adventure", a three-part series inspired by Jules Verne's first novel "Five Weeks in a Balloon". It followed Tompkinson and his guide, hot air ballooning expert Robin Batchelor, as they travelled 6,108 miles in six weeks from coast to coast, above and on the ground in Tanzania, Rwanda, Zambia, Botswana and Namibia. The series aired on ITV in the UK in June 2009 and was later distributed by American Public Television in the U.S. The African balloon series was well received, and ITV commissioned a three-part follow-up series that aired on ITV1 in 2010, titled "Stephen Tompkinson's Australian Balloon Adventure".


title: Stephen Tompkinson

text: He has done a variety of voice-over work, including adverts, audio books, and narration. His many adverts include BT Childline, British Midland, Motorola, Alton Towers, Comet, Eurostar, Laphroaig Whisky, Mercury & Kwiksave, Bulmers Cider, Tetley Tea and the People's Dispensary for Sick Animals.


title: Stephen Tompkinson

text: His narrated TV programmes and shows include "Little Red Tractor", "Trail of Guilt: Harold Shipman: Addicted to Murder" (2000), "When Snooker Ruled the World" (2002), "A Band for Britain" (2010)and "Choccywoccydoodah" (2014). In addition, he has narrated numerous audiobooks.


title: Stephen Tompkinson

text: In 2006, Tompkinson made his directing debut in the Midlands, at the helm of the BBC1 afternoon drama "The Lightning Kid". He was shadowed by a film crew making the documentary "Director's Debut: Stephen Tompkinson's Story" that aired immediately prior to the drama, with the intent of revealing the challenges faced by a new director.


title: Stephen Tompkinson

text: Tompkinson has supported various causes by providing promotional videos or voiceovers. These include a fundraising effort toward research to find a cure for Duchenne Muscular Dystrophy (DMD) and a financial appeal by Chester Zoo He has also supported causes such as the Westminster Carers Time Bank and, in 2008, he became an Ambassador for Project African Wilderness (PAW), a not-for-profit organisation that seeks to protect and restore the Mwabvi Wildlife Reserve in Malawi.


title: Stephen Tompkinson

text: In February 2012, Tompkinson supported the launch of a foundation established by Robbie Elliot, the former Newcastle United footballer who had helped Tompkinson improve his fitness for filming "Harrigan". Elliott was proposing to complete a charity bicycle ride to raise funds for the Sir Bobby Robson Foundation and Breakthrough Breast Cancer. Stories captured along the ride – from Lisbon to Newcastle – will be made into a documentary narrated by Tompkinson and premiered in London in late 2012.


title: Stephen Tompkinson

text: In late 2011, he recorded an advert for Text Santa, a charity initiative set up by ITV to support nine UK charities at Christmas. Stars of other ITV shows made similar adverts. In January 2012, it was announced that £4,120,000 was raised for the various charities.


title: Stephen Tompkinson

text: Over the years he has participated in Comic Relief's Red Nose Day. In 2001, he was one of the team describing the work the charity does in Britain, helping victims of early Alzheimer's or teenagers who are HIV positive. In 1997, Tompkinson and Kirwan did a Comic Relief sketch titled "Ballykissdibley" – with Dawn French and the cast of The Vicar of Dibley – in which they played their "Ballykissangel" characters, Fr. Peter Clifford and Assumpta Fitzgerald.


title: Stephen Tompkinson

text: He was married to Celia Anastasia and subsequent to the couple's divorce he became engaged to "Ballykissangel" co-star Dervla Kirwan. He then married Nicci Taylor, with whom he has a daughter, Daisy Ellen. It was announced in December 2006 that they had separated and would divorce.


title: Stephen Tompkinson

text: He is an avid cricket fan. He once said that if he wasn't an actor he "wouldn't mind travelling the world as a cricket commentator, enjoying endless summers." In 2008 he wrote an article for "The Wisden Cricketer" about Darren Gough.


title: Stephen Tompkinson

text: On 10 August 2022, Tompkinson pleaded not guilty to inflicting grievous bodily harm. Tompkinson is set to appear at Crown Court for trial in September 2022.


title: RS-25

text: The Aerojet Rocketdyne RS-25, also known as the Space Shuttle Main Engine (SSME), is a liquid-fuel cryogenic rocket engine that was used on NASA's Space Shuttle and is currently used on the Space Launch System (SLS).


title: RS-25

text: Designed and manufactured in the United States by Rocketdyne (later Pratt & Whitney Rocketdyne and Aerojet Rocketdyne), the RS-25 burns cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing thrust at liftoff. Although RS-25 heritage traces back to the 1960s, its concerted development began in the 1970s with the first flight, STS-1, on April 12, 1981. The RS-25 has undergone upgrades over its operational history to improve the engine's reliability, safety, and maintenance load.


title: RS-25

text: The engine produces a specific impulse ("I") of in a vacuum, or at sea level, has a mass of approximately , and is capable of throttling between 67% and 109% of its rated power level in one-percent increments. Components of the RS-25 operate at temperatures ranging from .


title: RS-25

text: The Space Shuttle used a cluster of three RS-25 engines mounted at the stern of the orbiter, with fuel drawn from the external tank. The engines were used for propulsion throughout the spacecraft ascent, with total thrust increased by two solid rocket boosters and the orbiter's two AJ10 orbital maneuvering system engines. Following each flight, the RS-25 engines were removed from the orbiter, inspected, refurbished, and then reused on another mission. On Space Launch System flights, the engines are expended. For the first four flights, engines left over from the Space Shuttle program will be refurbished and used before NASA switches to the simplified RS-25E variant.


title: RS-25

text: The RS-25 engine consists of pumps, valves, and other components working in concert to produce thrust. Fuel (liquid hydrogen) and oxidizer (liquid oxygen) from the Space Shuttle's external tank entered the orbiter at the umbilical disconnect valves and from there flowed through the orbiter's main propulsion system (MPS) feed lines; whereas in the Space Launch System (SLS), fuel and oxidizer from the rocket's core stage will flow directly into the MPS lines. Once in the MPS lines, the fuel and oxidizer each branch out into separate paths to each engine (three on the Space Shuttle, four on the SLS). In each branch, pre-valves then allow the propellants to enter the engine.


title: RS-25

text: Once in the engine, the propellants flow through low-pressure fuel and oxidizer turbopumps (LPFTP and LPOTP), and from there into high-pressure turbopumps (HPFTP and HPOTP). From these HPTPs the propellants take different routes through the engine. The oxidizer is split into four separate paths: to the oxidizer heat exchanger, which then splits into the oxidizer tank pressurization and pogo suppression systems; to the low-pressure oxidizer turbopump (LPOTP); to the high-pressure oxidizer pre-burner, from which it is split into the HPFTP turbine and HPOTP before being reunited in the hot gas manifold and sent on to the main combustion chamber (MCC); or directly into the main combustion chamber (MCC) injectors.


title: RS-25

text: Meanwhile, fuel flows through the main fuel valve into regenerative cooling systems for the nozzle and MCC, or through the chamber coolant valve. The fuel passing through the MCC cooling system then passes back through the LPFTP turbine before being routed either to the fuel tank pressurization system or to the hot gas manifold cooling system (from where it passes into the MCC). Fuel in the nozzle cooling and chamber coolant valve systems is then sent via pre-burners into the HPFTP turbine and HPOTP before being reunited again in the hot gas manifold, from where it passes into the MCC injectors. Once in the injectors, the propellants are mixed and injected into the main combustion chamber where they are ignited. The ejection of the burning propellant mixture through the throat and bell of the engine's nozzle creates the thrust.


title: RS-25

text: The low-pressure oxidizer turbopump (LPOTP) is an axial-flow pump which operates at approximately 5,150 rpm driven by a six-stage turbine powered by high-pressure liquid oxygen from the high-pressure oxidizer turbopump (HPOTP). It boosts the liquid oxygen's pressure from , with the flow from the LPOTP then being supplied to the HPOTP. During engine operation, the pressure boost permits the high-pressure oxidizer turbine to operate at high speeds without cavitating. The LPOTP, which measures approximately , is connected to the vehicle propellant ducting and supported in a fixed position by being mounted on the launch vehicle's structure.


title: RS-25

text: Then, mounted before the HPOTP, is the pogo oscillation suppression system accumulator. For use, it is pre-and post-charged with and charged with gaseous from the heat exchanger, and, not having any membrane, it operates by continuously recirculating the charge gas. A number of baffles of various types are present inside the accumulator to control sloshing and turbulence, which is useful of itself and also to prevent the escape of gas into the low-pressure oxidizer duct to be ingested in the HPOTP.


title: RS-25

text: The HPOTP consists of two single-stage centrifugal pumps (the main pump and a pre-burner pump) mounted on a common shaft and driven by a two-stage, hot-gas turbine. The main pump boosts the liquid oxygen's pressure from while operating at approximately 28,120 rpm, giving a power output of . The HPOTP discharge flow splits into several paths, one of which drives the LPOTP turbine. Another path is to, and through, the main oxidizer valve and enters the main combustion chamber. Another small flow path is tapped off and sent to the oxidizer heat exchanger. The liquid oxygen flows through an anti-flood valve that prevents it from entering the heat exchanger until sufficient heat is present for the heat exchanger to utilize the heat contained in the gases discharged from the HPOTP turbine, converting the liquid oxygen to gas. The gas is sent to a manifold and then routed to pressurize the liquid oxygen tank. Another path enters the HPOTP second-stage pre-burner pump to boost the liquid oxygen's pressure from 30 to 51 MPa (4,300 psia to 7,400 psia). It passes through the oxidizer pre-burner oxidizer valve into the oxidizer pre-burner and through the fuel pre-burner oxidizer valve into the fuel pre-burner. The HPOTP measures approximately . It is attached by flanges to the hot-gas manifold.


title: RS-25

text: The HPOTP turbine and HPOTP pumps are mounted on a common shaft. Mixing of the fuel-rich hot gases in the turbine section and the liquid oxygen in the main pump can create a hazard and, to prevent this, the two sections are separated by a cavity that is continuously purged by the engine's helium supply during engine operation. Two seals minimize leakage into the cavity; one seal is located between the turbine section and the cavity, while the other is between the pump section and cavity. Loss of helium pressure in this cavity results in automatic engine shutdown.


title: RS-25

text: The low-pressure fuel turbopump (LPFTP) is an axial-flow pump driven by a two-stage turbine powered by gaseous hydrogen. It boosts the pressure of the liquid hydrogen from 30 to 276 psia (0.2 to 1.9 MPa) and supplies it to the high-pressure fuel turbopump (HPFTP). During engine operation, the pressure boost provided by the LPFTP permits the HPFTP to operate at high speeds without cavitating. The LPFTP operates at around 16,185 rpm, and is approximately in size. It is connected to the vehicle propellant ducting and is supported in a fixed position by being mounted to the launch vehicle's structure.


title: RS-25

text: The HPFTP is a three-stage centrifugal pump driven by a two-stage hot-gas turbine. It boosts the pressure of the liquid hydrogen from 1.9 to 45 MPa (276 to 6,515 psia), and operates at approximately 35,360 rpm with a power of 71,140 hp. The discharge flow from the turbopump is routed to, and through, the main valve and is then split into three flow paths. One path is through the jacket of the main combustion chamber, where the hydrogen is used to cool the chamber walls. It is then routed from the main combustion chamber to the LPFTP, where it is used to drive the LPFTP turbine. A small portion of the flow from the LPFTP is then directed to a common manifold from all three engines to form a single path to the liquid hydrogen tank to maintain pressurization. The remaining hydrogen passes between the inner and outer walls of the hot-gas manifold to cool it and is then discharged into the main combustion chamber. A second hydrogen flow path from the main fuel valve is through the engine nozzle (to cool the nozzle). It then joins the third flow path from the chamber coolant valve. This combined flow is then directed to the fuel and oxidizer pre-burners. The HPFTP is approximately in size and is attached to the hot-gas manifold by flanges.


title: RS-25

text: The oxidizer and fuel pre-burners are welded to the hot-gas manifold. The fuel and oxidizer enter the pre-burners and are mixed so that efficient combustion can occur. The augmented spark igniter is a small combination chamber located in the center of the injector of each pre-burner. Two dual-redundant spark igniters are activated by the engine controller and are used during the engine start sequence to initiate combustion in each pre-burner. They are turned off after approximately three seconds because the combustion process is then self-sustaining. The pre-burners produce the fuel-rich hot gases that pass through the turbines to generate the power needed to operate the high-pressure turbopumps. The oxidizer pre-burner's outflow drives a turbine that is connected to the HPOTP and to the oxidizer pre-burner pump. The fuel pre-burner's outflow drives a turbine that is connected to the HPFTP.


title: RS-25

text: The speed of the HPOTP and HPFTP turbines depends on the position of the corresponding oxidizer and fuel pre-burner oxidizer valves. These valves are positioned by the engine controller, which uses them to throttle the flow of liquid oxygen to the pre-burners and, thus, control engine thrust. The oxidizer and fuel pre-burner oxidizer valves increase or decrease the liquid oxygen flow, thus increasing or decreasing pre-burner chamber pressure, HPOTP and HPFTP turbine speed, and liquid oxygen and gaseous hydrogen flow into the main combustion chamber, which increases or decreases engine thrust. The oxidizer and fuel pre-burner valves operate together to throttle the engine and maintain a constant 6.03:1 propellant mixture ratio.


title: RS-25

text: The main oxidizer and main fuel valves control the flow of liquid oxygen and liquid hydrogen into the engine and are controlled by each engine controller. When an engine is operating, the main valves are fully open.


title: RS-25

text: The engine's main combustion chamber (MCC) receives fuel-rich hot gas from a hot-gas manifold cooling circuit. The gaseous hydrogen and liquid oxygen enter the chamber at the injector, which mixes the propellants. The mixture is ignited by the "Augmented Spark Igniter", an H/O flame at the center of the injector head. The main injector and dome assembly are welded to the hot-gas manifold, and the MCC is also bolted to the hot-gas manifold. The MCC comprises a structural shell made of Inconel 718 which is lined with a copper-silver-zirconium alloy called NARloy-Z, developed specifically for the RS-25 in the 1970s. Around 390 channels are machined into the liner wall to carry liquid hydrogen through the liner to provide MCC cooling, as the temperature in the combustion chamber reaches 3300 °C (6000 °F) during flight – higher than the boiling point of iron.


title: RS-25

text: An alternative for the construction of RS-25 engines to be used in SLS missions is the use of advanced structural ceramics, such as thermal barrier coatings (TBCs) and ceramic-matrix composites (CMCs). These materials possess significantly lower thermal conductivities than metallic alloys, thus allowing more efficient combustion and reducing the cooling requirements. TBCs are thin ceramic oxide layers deposited on metallic components, acting as a thermal barrier between hot gaseous combustion products and the metallic shell. A TBC applied to the Inconel 718 shell during production could extend engine life and reduce cooling costs. Further, CMCs have been studied as a replacement for Ni-based superalloys and are composed of high-strength fibers (BN, C) continuously dispersed in a SiC matrix. An MCC composed of a CMC, though less studied and farther from fruition than the application of a TBC, could offer unprecedented levels of engine efficiency.


title: RS-25

text: The engine's nozzle is long with a diameter of at its throat and at its exit. The nozzle is a bell-shaped extension bolted to the main combustion chamber, referred to as a de Laval nozzle. The RS-25 nozzle has an unusually large expansion ratio (about 69:1) for the chamber pressure. At sea level, a nozzle of this ratio would normally undergo flow separation of the jet from the nozzle, which would cause control difficulties and could even mechanically damage the vehicle. However, to aid the engine's operation Rocketdyne engineers varied the angle of the nozzle walls from the theoretical optimum for thrust, reducing it near the exit. This raises the pressure just around the rim to an absolute pressure between , and prevents flow separation. The inner part of the flow is at much lower pressure, around or less. The inner surface of each nozzle is cooled by liquid hydrogen flowing through brazed stainless steel tube wall coolant passages. On the Space Shuttle, a support ring welded to the forward end of the nozzle is the engine attach point to the orbiter-supplied heat shield. Thermal protection is necessary because of the exposure portions of the nozzles experience during the launch, ascent, on-orbit and entry phases of a mission. The insulation consists of four layers of metallic batting covered with a metallic foil and screening.


title: RS-25

text: Each engine is equipped with a main engine controller (MEC), an integrated computer which controls all of the engine's functions (through the use of valves) and monitors its performance. Built by Honeywell Aerospace, each MEC originally comprised two redundant Honeywell HDC-601 computers, later upgraded to a system composed of two doubly redundant Motorola 68000 (M68000) processors (for a total of four M68000s per controller). Having the controller installed on the engine itself greatly simplifies the wiring between the engine and the launch vehicle, because all the sensors and actuators are connected directly to only the controller, each MEC then being connected to the orbiter's general purpose computers (GPCs) or the SLS's avionics suite via its own engine interface unit (EIU). Using a dedicated system also simplifies the software and thus improves its reliability.


title: RS-25

text: Two independent dual-CPU computers, A and B, form the controller; giving redundancy to the system. The failure of controller system A automatically leads to a switch-over to controller system B without impeding operational capabilities; the subsequent failure of controller system B would provide a graceful shutdown of the engine. Within each system (A and B), the two M68000s operate in lock-step, thereby enabling each system to detect failures by comparing the signal levels on the buses of the two M68000 processors within that system. If differences are encountered between the two buses, then an interrupt is generated and control turned over to the other system. Because of subtle differences between M68000s from Motorola and the second source manufacturer TRW, each system uses M68000s from the same manufacturer (for instance system A would have two Motorola CPUs while system B would have two CPUs manufactured by TRW). Memory for block I controllers was of the plated-wire type, which functions in a manner similar to magnetic core memory and retains data even after power is turned off. Block II controllers used conventional CMOS static RAM.


title: RS-25

text: The controllers were designed to be tough enough to survive the forces of launch and proved to be extremely resilient to damage. During the investigation of the "Challenger" accident the two MECs (from engines 2020 and 2021), recovered from the seafloor, were delivered to Honeywell Aerospace for examination and analysis. One controller was broken open on one side, and both were severely corroded and damaged by marine life. Both units were disassembled and the memory units flushed with deionized water. After they were dried and vacuum baked, data from these units was retrieved for forensic examination.


title: RS-25

text: To control the engine's output, the MEC operates five hydraulically actuated propellant valves on each engine; the oxidizer pre-burner oxidizer, fuel pre-burner oxidizer, main oxidizer, main fuel, and chamber coolant valves. In an emergency, the valves can be fully closed by using the engine's helium supply system as a backup actuation system.


title: RS-25

text: In the Space Shuttle, the main oxidizer and fuel bleed valves were used after shutdown to dump any residual propellant, with residual liquid oxygen venting through the engine and residual liquid hydrogen venting through the liquid hydrogen fill and drain valves. After the dump was completed, the valves closed and remained closed for the remainder of the mission.


title: RS-25

text: A coolant control valve is mounted on the combustion chamber coolant bypass duct of each engine. The engine controller regulates the amount of gaseous hydrogen allowed to bypass the nozzle coolant loop, thus controlling its temperature. The chamber coolant valve is 100% open before the engine start. During engine operation, it is 100% open for throttle settings of 100 to 109%. For throttle settings between 65 and 100%, its position ranged from 66.4 to 100%.


title: RS-25

text: Each engine is installed with a gimbal bearing, a universal ball and socket joint which is bolted to the launch vehicle by its upper flange and to the engine by its lower flange. It represents the thrust interface between the engine and the launch vehicle, supporting of engine weight and withstanding over of thrust. As well as providing a means to attach the engine to the launch vehicle, the gimbal bearing allows the engine to be pivoted (or "gimballed") around two axes of freedom with a range of ±10.5°. This motion allows the engine's thrust vector to be altered, thus steering the vehicle into the correct orientation. The comparatively large gimbal range is necessary to correct for the pitch momentum that occurs due to the constantly shifting center of mass as the vehicle burns fuel in flight and after booster separation. The bearing assembly is approximately , has a mass of , and is made of titanium alloy.


title: RS-25

text: The low-pressure oxygen and low-pressure fuel turbopumps were mounted 180° apart on the orbiter's aft fuselage thrust structure. The lines from the low-pressure turbopumps to the high-pressure turbopumps contain flexible bellows that enable the low-pressure turbopumps to remain stationary while the rest of the engine is gimbaled for thrust vector control, and also to prevent damage to the pumps when loads were applied to them. The liquid-hydrogen line from the LPFTP to the HPFTP is insulated to prevent the formation of liquid air.


title: RS-25

text: In addition to fuel and oxidizer systems, the launch vehicle's main propulsion system is also equipped with a helium system consisting of ten storage tanks in addition to various regulators, check valves, distribution lines, and control valves. The system is used in-flight to purge the engine and provides pressure for actuating engine valves within the propellant management system and during emergency shutdowns. During entry, on the Space Shuttle, any remaining helium was used to purge the engines during reentry and for repressurization.


title: RS-25

text: The history of the RS-25 traces back to the 1960s when NASA's Marshall Space Flight Center and Rocketdyne were conducting a series of studies on high-pressure engines, developed from the successful J-2 engine used on the S-II and S-IVB upper stages of the Saturn V rocket during the Apollo program. The studies were conducted under a program to upgrade the Saturn V engines, which produced a design for a upper-stage engine known as the HG-3. As funding levels for Apollo wound down the HG-3 was cancelled as well as the upgraded F-1 engines already being tested. It was the design for the HG-3 that would form the basis for the RS-25.


title: RS-25

text: Meanwhile, in 1967, the US Air Force funded a study into advanced rocket propulsion systems for use during Project Isinglass, with Rocketdyne asked to investigate aerospike engines and Pratt & Whitney (P&W) to research more efficient conventional de Laval nozzle-type engines. At the conclusion of the study, P&W put forward a proposal for a 250,000 lb engine called the XLR-129, which used a two-position expanding nozzle to provide increased efficiency over a wide range of altitudes.


title: RS-25

text: In January 1969 NASA awarded contracts to General Dynamics, Lockheed, McDonnell Douglas, and North American Rockwell to initiate the early development of the Space Shuttle. As part of these 'Phase A' studies, the involved companies selected an upgraded version of the XLR-129, developing , as the baseline engine for their designs. This design can be found on many of the planned Shuttle versions right up to the final decision. However, since NASA was interested in pushing the state of the art in every way they decided to select a much more advanced design in order to "force an advancement of rocket engine technology". They called for a new design based on a high-pressure combustion chamber running around , which increases the performance of the engine.


title: RS-25

text: Development began in 1970, when NASA released a request for proposal for 'Phase B' main engine concept studies, requiring development of a throttleable, staged combustion, de Laval-type engine. The request was based on the then-current design of the Space Shuttle which featured two reusable stages, the orbiter and a crewed fly-back booster, and required one engine which would be able to power both vehicles via two different nozzles (12 booster engines with sea level thrust each and 3 orbiter engines with vacuum thrust each). Rocketdyne, P&W and Aerojet General were selected to receive funding although, given P&W's already-advanced development (demonstrating a working concept engine during the year) and Aerojet General's prior experience in developing the M-1 engine, Rocketdyne was forced to put a large amount of private money into the design process to allow the company to catch up to its competitors.


title: RS-25

text: By the time the contract was awarded, budgetary pressures meant that the shuttle's design had changed to its final orbiter, external tank, and two boosters configuration, and so the engine was only required to power the orbiter during ascent. During the year-long 'Phase B' study period, Rocketdyne was able to make use of their experience developing the HG-3 engine to design their SSME proposal, producing a prototype by January 1971. The engine made use of a new Rocketdyne-developed copper-zirconium alloy (called NARloy-Z) and was tested on February 12, 1971, producing a chamber pressure of . The three participating companies submitted their engine development bids in April 1971, with Rocketdyne being awarded the contract on July 13, 1971—although work did not begin on engine development until March 31, 1972, due to a legal challenge from P&W.


title: RS-25

text: Following the awarding of the contract, a preliminary design review was carried out in September 1972, followed by a critical design review in September 1976 after which the engine's design was set and construction of the first set of flight-capable engines began. A final review of all the Space Shuttle's components, including the engines, was conducted in 1979. The design reviews operated in parallel with several test milestones, initial tests consisting of individual engine components which identified shortcomings with various areas of the design, including the HPFTP, HPOTP, valves, nozzle, and fuel pre-burners. The individual engine component tests were followed by the first test of a complete engine (0002) on March 16, 1977. NASA specified that, prior to the Shuttle's first flight, the engines must have undergone at least 65,000 seconds of testing, a milestone that was reached on March 23, 1980, with the engine having undergone 110,253 seconds of testing by the time of STS-1 both on test stands at Stennis Space Center and installed on the Main Propulsion Test Article (MPTA). The first set of engines (2005, 2006 and 2007) was delivered to Kennedy Space Center in 1979 and installed on , before being removed in 1980 for further testing and reinstalled on the orbiter. The engines, which were of the first manned orbital flight (FMOF) configuration and certified for operation at 100% rated power level (RPL), were operated in a twenty-second flight readiness firing on February 20, 1981, and, after inspection, declared ready for flight.


title: RS-25

text: Each Space Shuttle had three RS-25 engines, installed in the aft structure of the Space Shuttle orbiter in the Orbiter Processing Facility prior to the orbiter being transferred to the Vehicle Assembly Building. If necessary the engines could be changed on the pad. The engines, drawing propellant from the Space Shuttle external tank (ET) via the orbiter's main propulsion system (MPS), were ignited at T−6.6 seconds prior to liftoff (with each ignition staggered by 120 ms), which allowed their performance to be checked prior to ignition of the Space Shuttle Solid Rocket Boosters (SRBs), which committed the shuttle to the launch. At launch, the engines would be operating at 100% RPL, throttling up to 104.5% immediately following liftoff. The engines would maintain this power level until around T+40 seconds, where they would be throttled back to around 70% to reduce aerodynamic loads on the shuttle stack as it passed through the region of maximum dynamic pressure, or max. "q". The engines would then be throttled back up until around T+8 minutes, at which point they would be gradually throttled back down to 67% to prevent the stack exceeding 3 g of acceleration as it became progressively lighter due to propellant consumption. The engines were then shut down, a procedure known as main engine cutoff (MECO), at around T+8.5 minutes.


title: RS-25

text: After each flight the engines would be removed from the orbiter and transferred to the Space Shuttle Main Engine Processing Facility (SSMEPF), where they would be inspected and refurbished in preparation for reuse on a subsequent flight. A total of 46 reusable RS-25 engines, each costing around US$40 million, were flown during the Space Shuttle program, with each new or overhauled engine entering the flight inventory requiring flight qualification on one of the test stands at Stennis Space Center prior to flight.


title: RS-25

text: Over the course of the Space Shuttle program, the RS-25 went through a series of upgrades, including combustion chamber changes, improved welds and turbopump changes in an effort to improve the engine's performance and reliability and so reduce the amount of maintenance required after use. As a result, several versions of the RS-25 were used during the program:


title: RS-25

text: The most obvious effects of the upgrades the RS-25 received through the Space Shuttle program were the improvements in engine throttle. Whilst the FMOF engine had a maximum output of 100% RPL, Block II engines could throttle as high as 109% or 111% in an emergency, with usual flight performance being 104.5%. These increases in throttle level made a significant difference to the thrust produced by the engine:


title: RS-25

text: Specifying power levels over 100% may seem nonsensical, but there was a logic behind it. The 100% level does not mean the maximum physical power level attainable, rather it was a specification decided on during engine development—the expected rated power level. When later studies indicated the engine could operate safely at levels above 100%, these higher levels became standard. Maintaining the original relationship of power level to physical thrust helped reduce confusion, as it created an unvarying fixed relationship so that test data (or operational data from past or future missions) can be easily compared. If the power level was increased, and that new value was said to be 100%, then all previous data and documentation would either require changing or cross-checking against what physical thrust corresponded to 100% power level on that date. Engine power level affects engine reliability, with studies indicating the probability of an engine failure increasing rapidly with power levels over 104.5%, which was why power levels above 104.5% were retained for contingency use only.


title: RS-25

text: During the course of the Space Shuttle program, a total of 46 RS-25 engines were used (with one extra RS-25D being built but never used). During the 135 missions, for a total of 405 individual engine-missions, Pratt & Whitney Rocketdyne reports a 99.95% reliability rate, with the only in-flight SSME failure occurring during 's STS-51-F mission. The engines, however, did suffer from a number of pad failures (redundant set launch sequencer aborts, or RSLSs) and other issues during the course of the program:


title: RS-25

text: During the period preceding final Space Shuttle retirement, various plans for the remaining engines were proposed, ranging from them all being kept by NASA, to them all being given away (or sold for US$400,000–800,000 each) to various institutions such as museums and universities. This policy followed changes to the planned configurations of the Constellation program's Ares V cargo-launch vehicle and Ares I crew-launch vehicle rockets, which had been planned to use the RS-25 in their first and second stages respectively. While these configurations had initially seemed worthwhile, as they would use then-current technology following the shuttle's retirement in 2010, the plan had several drawbacks:


title: RS-25

text: Following several design changes to the Ares I and Ares V rockets, the RS-25 was to be replaced with a single J-2X engine for the Ares I second stage and six modified RS-68 engines (which was based on both the SSME and Apollo-era J-2 engine) on the Ares V core stage; this meant that the RS-25 would be retired along with the space shuttle fleet. In 2010, however, NASA was directed to halt the Constellation program, and with it development of the Ares I and Ares V, instead of focusing on building a new heavy-lift launcher.


title: RS-25

text: On September 14, 2011, following the retirement of the Space Shuttle, NASA announced that it would be developing a new launch vehicle, known as the Space Launch System (SLS), to replace the shuttle fleet. The design for the SLS features the RS-25 as part of its core stage, with different versions of the rocket being equipped with between three and five engines. The initial flights of the new launch vehicle will make use of previously flown Block II RS-25D engines, with NASA keeping such engines in a "purged safe" environment at Stennis Space Center, "along with all of the ground systems required to maintain them."


title: RS-25

text: In addition to the RS-25Ds, the SLS program will make use of the Main Propulsion Systems (MPS) from the three remaining shuttle orbiters for testing purposes (having been removed as part of the orbiters' decommissioning), with the first two launches (Artemis 1 and Artemis 2) possibly making use of the MPS hardware from Space Shuttles and in their core stages. The SLS's propellants will be supplied to the engines from the rocket's core stage, which will consist of a modified Space Shuttle external tank with the MPS plumbing and engines at its aft, and an interstage structure at the top.


title: RS-25

text: Once the remaining RS-25Ds are used up, they are to be replaced with a cheaper, expendable version, currently designated the RS-25E. This engine may be based on one or both of two single-use variants that were studied in 2005, the RS-25E (referred to as the Minimal Change Expendable SSME) and the even-more-simplified RS-25F (referred to as the Low Cost Manufacture Expendable SSME), both of which were under consideration in 2011 and are currently under development by Aerojet Rocketdyne.


title: RS-25

text: On May 1, 2020, NASA awarded a contract extension to manufacture 18 additional RS-25 engines, with associated services, for $1.79 billion, bringing the total SLS contract value to almost $3.5 billion.


title: RS-25

text: On August 29, 2022, Artemis 1 was delayed by a problem with engineering sensors on RS-25D #3 erroneously reporting that it hadn't chilled down to its ideal operating temperature.


title: RS-25

text: In 2015, a test campaign was conducted to determine RS-25 engine performance with a new engine controller unit, under lower liquid-oxygen temperatures, with greater inlet pressure due to the taller SLS core-stage liquid-oxygen tank and higher vehicle acceleration; and with more nozzle heating due to the four-engine configuration and its position in-plane with the SLS booster exhaust nozzles. New ablative heat-shield insulation was to be tested as well. Tests occurred on January 9, May 28, June 11 (500 seconds), July 17 (535 seconds), August 13 and August 27.


title: RS-25

text: Following these tests, four more engines were scheduled to enter a new test cycle. A new series of tests designed to evaluate performance in SLS-use cases was initiated in 2017.


title: RS-25

text: On February 28, 2019, NASA conducted a 510-second test burn of a developmental RS-25 at 113 percent of its originally designed thrust for more than 430 seconds, about four times longer than any prior test at this thrust level.


title: RS-25

text: On January 16, 2021, the RS-25 engines were fired again, during a hot-fire test as part of the Artemis program. The test was originally scheduled as an 8-minute test but was terminated at the 67th second due to intentionally conservative test parameters being breached in the hydraulic system of Engine 2's Core Stage Auxiliary Power Unit (CAPU) during the thrust vector control (TVC) system test. Engine 2's CAPU was shut down automatically, although if this issue had occurred during flight, it would not have caused an abort, as the remaining CAPUs are capable of powering the TVC systems of all four engines. The engine also suffered a different "Major Component Failure", in the engine control system, that was caused by instrumentation failure. This have triggered an abort of the launch countdown during an actual launch attempt.


title: RS-25

text: On March 18, 2021, the four RS-25 core-stage engines were once again fired as part of the second SLS core stage hot-fire test, which lasted the full duration of 500 seconds, successfully certifying the Artemis 1 core stage for flight.


title: RS-25

text: On December 14, 2022, a single development RS-25E, serial number E10001, attempted a 500 second hot-fire test. The test aborted at T+209.5 seconds for unknown reasons.


title: RS-25

text: On May 24, 2017, DARPA announced that they had selected The Boeing Company to complete design work on the XS-1 program. The technology demonstrator was planned to use an Aerojet Rocketdyne AR-22 engine. The AR-22 was a version of the RS-25, with parts sourced from Aerojet Rocketdyne and NASA inventories from early versions of the engine. In July 2018 Aerojet Rocketdyne successfully completed ten 100-second firings of the AR-22 in ten days.


title: RS-25

text: On January 22, 2020, Boeing announced that they were dropping out of the XS-1 program, leaving no role for the AR-22.


title: Postpartum period

text: The postpartum (or postnatal) period begins after childbirth and is typically considered to end within 6 weeks as the mother's body, including hormone levels and uterus size, returns to a non-pregnant state. The terms puerperium, puerperal period, or immediate postpartum period are commonly used to refer to the first six weeks following childbirth. The World Health Organization (WHO) describes the postnatal period as the most critical and yet the most neglected phase in the lives of mothers and babies; most maternal and newborn deaths occur during this period.


title: Postpartum period

text: In scientific literature, the term is commonly abbreviated to P"x, where x" is a number; for example, "day P5" should be read as "the fifth day after birth". This is not to be confused with the medical nomenclature that uses G P to stand for number and outcomes of pregnancy (gravidity and parity).


title: Postpartum period

text: A female giving birth in a hospital may leave as soon as they are medically stable, which can be as early as a few hours postpartum, though the average for a vaginal birth is one to two days. The average caesarean section postnatal stay is three to four days. During this time, the mother is monitored for bleeding, bowel and bladder function, and baby care. The infant's health is also monitored. Early postnatal hospital discharge is typically defined as discharge of the mother and newborn from the hospital within 48 hours of birth.


title: Postpartum period

text: The postpartum period can be divided into three distinct stages; the initial or acute phase, 8–19 hours after childbirth; subacute postpartum period, which lasts two to six weeks, and the delayed postpartum period, which can last up to eight months. In the subacute postpartum period, 87% to 94% of women report at least one health problem. Long-term health problems (persisting after the delayed postpartum period) are reported by 31% of women.


title: Postpartum period

text: Various organizations recommend routine postpartum evaluation at certain time intervals in the postpartum period.


title: Postpartum period

text: The first 6 to 12 hours after childbirth is the initial or acute phase of the postpartum period. During this time the mother is typically monitored by nurses or midwives as complications can arise.


title: Postpartum period

text: The greatest health risk in the acute phase is postpartum bleeding. Following delivery the area where the placenta was attached to the uterine wall bleeds, and the uterus must contract to prevent blood loss. After contraction takes place the fundus (top) of the uterus can be palpated as a firm mass at the level of the navel. It is important that the uterus remains firm and the nurse or midwife will make frequent assessments of both the fundus and the amount of bleeding. Uterine massage is commonly used to help the uterus contract.


title: Postpartum period

text: Following delivery if the mother had an episiotomy or tearing at the opening of the vagina, it is stitched. In the past, an episiotomy was routine. However, more recent research shows that routine episiotomy, when a normal delivery without complications or instrumentation is anticipated, does not offer benefits in terms of reducing perineal or vaginal trauma. Selective use of episiotomy results in less perineal trauma. A healthcare professional can recommend comfort measures to help to ease perineal pain.


title: Postpartum period

text: Within about 10 seconds the infant takes its first breath and the caregiver places the baby on the mother's chest. The infant's condition is evaluated using the Apgar scale. The Apgar score is determined by evaluating the newborn baby on five criteria which are summarized using words chosen to form an acronym (Appearance, Pulse, Grimace, Activity, Respiration). Until recently babies were routinely removed from their mothers following birth; however beginning around 2000, some authorities began to suggest that early skin-to-skin contact (placing the naked baby on the mother's chest) is of benefit to both mother and infant. As of 2014, early skin-to-skin contact, also called kangaroo care, is endorsed by all major organizations that are responsible for the well-being of infants. Thus, to help establish bonding and successful breastfeeding, the caregiver carries out immediate mother and infant assessments as the infant lies on the mother's chest and removes the infant for further observations only after they have had their first breastfeed, depending on the mother's preference. The World Health Organization (WHO) also encourages skin-to-skin contact for the first 24 hours after birth to help regulate the baby's temperature.


title: Postpartum period

text: The subacute postpartum starts after the acute postpartum period concludes and can last for two to six weeks.


title: Postpartum period

text: In the first few days following childbirth, the risk of a deep vein thrombosis (DVT) is relatively high as hypercoagulability increases during pregnancy and is maximal in the postpartum period, particularly for women with C-section with reduced mobility. Anti-coagulants or physical methods such as compression may be used in the hospital, particularly if the woman has risk factors, such as obesity, prolonged immobility, recent C-section, or first-degree relative with a history of thrombotic episode. For women with a history of thrombotic event in pregnancy or prior to pregnancy, anticoagulation is generally recommended.


title: Postpartum period

text: The increased vascularity (blood flow) and edema (swelling) of the woman's vagina gradually resolves in about three weeks. The cervix gradually narrows and lengths over a few weeks. Postpartum infections can lead to sepsis and if untreated, death. Postpartum urinary incontinence is experienced by about 33% of all women; women who deliver vaginally are about twice as likely to have urinary incontinence as women who give birth via a cesarean. Urinary incontinence in this period increases the risk of long term incontinence. Kegel exercises are recommended to strengthen the pelvic floor muscles and control urinary incontinence.


title: Postpartum period

text: Discharge from the uterus, called lochia, will gradually decrease and turn from bright red, to brownish, to yellow and cease at around five or six weeks. Women are advised in this period to wear adult diapers or nappies, disposable maternity briefs, maternity pads or towels, or sanitary napkins. The use of tampons or menstrual cups are contraindicated as they may introduce bacteria and increase the risk of infection. An increase in lochia between 7–14 days postpartum may indicate delayed postpartum hemorrhage.


title: Postpartum period

text: At two to four days postpartum, a woman's breastmilk will generally come in. Historically, women who were not breastfeeding (nursing their babies) were given drugs to suppress lactation, but this is no longer medically indicated. In this period, difficulties with breastfeeding may arise. Maternal sleep is often disturbed as night waking is normal in the newborn, and newborns need to be fed every two to three hours, including during the night. The lactation consultant, health visitor, monthly nurse, postnatal doula, or "kraamverzorgster" may be of assistance at this time.


title: Postpartum period

text: During the subacute postpartum period, psychological disorders may emerge. Among these are postpartum depression, posttraumatic stress disorder, and in rare cases, postpartum psychosis. Postpartum mental illness can affect both mothers and fathers, and is not uncommon. Early detection and adequate treatment is required. Approximately 70–80% of postpartum women will experience the "baby blues" for a few days. Between 10 and 20 percent may experience clinical depression, with a higher risk among those women with a history of postpartum depression, clinical depression, anxiety, or other mood disorders. Prevalence of PTSD following normal childbirth (excluding stillbirth or major complications) is estimated to be between 2.8% and 5.6% at six weeks postpartum.


title: Postpartum period

text: Various organizations across the world recommend routine postpartum evaluation in the postpartum period. The American College of Obstetricians and Gynecologists (ACOG) recognizes the postpartum period (the "fourth trimester") as critical for women and infants. Instead of the traditional single four- to six-week postpartum visit, ACOG, as of 2018, recommends that postpartum care be an ongoing process. They recommend that all women have contact (either in person or by phone) with their obstetric provider within the first three weeks postpartum to address acute issues, with subsequent care as needed. A more comprehensive postpartum visit should be done at four to twelve weeks postpartum to address the mother's mood and emotional well-being, physical recovery after birth, infant feeding, pregnancy spacing and contraception, chronic disease management, and preventive health care and health maintenance. Women with hypertensive disorders should have a blood pressure check within three to ten days postpartum. More than one half of postpartum strokes occur within ten days of discharge after delivery. Women with chronic medical (e.g., hypertensive disorders, diabetes, kidney disease, thyroid disease) and psychiatric conditions should continue to follow with their obstetric or primary care provider for ongoing disease management. Women with pregnancies complicated by hypertension, gestational diabetes, or preterm birth should undergo counseling and evaluation for cardiometabolic disease, as lifetime risk of cardiovascular disease is higher in these women.


title: Postpartum period

text: Similarly, the World Health Organization recommends postpartum evaluation of the mother and infant at three days, one to two weeks, and six weeks postpartum.


title: Postpartum period

text: The delayed postpartum period starts after the subacute postpartum period and lasts up to six months. During this time, muscles and connective tissue returns to a pre-pregnancy state. Recovery from childbirth complications in this period, such as urinary and fecal incontinence, painful intercourse, and pelvic prolapse, are typically very slow and in some cases may not resolve. Symptoms of PTSD often subside in this period, dropping from 2.8% and 5.6% at six weeks postpartum to 1.5% at six months postpartum.


title: Postpartum period

text: Approximately three months after giving birth (typically between two and five months), estrogen levels drop and large amounts of hair loss is common, particularly in the temple area (postpartum alopecia). Hair typically grows back normally and treatment is not indicated. Other conditions that may arise in this period include postpartum thyroiditis.


title: Postpartum period

text: During this period, infant sleep during the night gradually increases and maternal sleep generally improves.


title: Postpartum period

text: Long-term health problems (persisting after the delayed postpartum period) are reported by 31% of women.


title: Postpartum period

text: Ongoing physical and mental health evaluation, risk factor identification, and preventive health care should be provided, as detailed above .


title: Postpartum period

text: Postpartum confinement refers to a system for recovery following childbirth. It begins immediately after the birth, and lasts for a culturally variable length: typically for one month or 30 days, up to 40 days, two months or 100 days. This postnatal recuperation can include "traditional health beliefs, taboos, rituals, and proscriptions." The practice used to be known as "lying-in", which, as the term suggests, centres around bed rest. (Maternity hospitals used to use this phrase, as in the General Lying-in Hospital.) Postpartum confinement customs are well-practiced in China, where it is known as "sitting the month", and similar customs manifest all over the world. A modern version of this rest period has evolved, to give maximum support to the new mother, especially if she is recovering from a difficult labour and delivery.


title: Intentional community

text: An intentional community is a voluntary residential community which is designed to have a high degree of social cohesion and teamwork from the start. The members of an intentional community typically hold a common social, political, religious, or spiritual vision, and typically share responsibilities and property. This way of life is sometimes characterized as an "alternative lifestyle". Intentional communities can be seen as social experiments or communal experiments. The multitude of intentional communities includes collective households, cohousing communities, coliving, ecovillages, monasteries, survivalist retreats, kibbutzim, hutterites, ashrams, and housing cooperatives.


title: Intentional community

text: Ashrams are likely the earliest intentional communities founded around 1500 BCE, while Buddhist monasteries appeared around 500 BCE. Pythagoras founded an intellectual vegetarian commune in about 525 BCE in southern Italy. Hundreds of modern intentional communities were formed across Europe, North and South America, Australia, and New Zealand out of the intellectual foment of utopianism. Intentional communities exhibit the utopian ambition to create a better, more sustainable world for living. Nevertheless, the term utopian community as a synonym for an intentional community might be considered to be of pejorative nature and many intentional communities do not consider themselves to be utopian. Also the alternative term commune is considered to be non-neutral or even linked to leftist politics or hippies.


title: Intentional community

text: Additional terms referring to an intentional community can be alternative lifestyle, intentional society, cooperative community, withdrawn community, enacted community, socialist colony, communistic society, collective settlement, communal society, mutualistic community, communitarian experiment, experimental community, utopian experiment, practical utopia, and utopian society.


title: Intentional community

text: The purposes of intentional communities vary and may be political, spiritual, economic, or environmental. In addition to spiritual communities, secular communities also exist. One common practice, particularly in spiritual communities, is communal meals. Egalitarian values can be combined with other values. Benjamin Zablocki categorized communities this way:


title: Intentional community

text: Members of Christian intentional communities want to emulate the practices of the earliest believers. Using the biblical book of Acts (and, often, the Sermon on the Mount) as a model, members of these communities strive to demonstrate their faith in a corporate context, and to live out the teachings of the New Testament, practicing compassion and hospitality. Communities such as the Simple Way, the Bruderhof and Rutba House would fall into this category. Despite strict membership criteria, these communities are open to visitors and not reclusive to the extent of some other intentional communities.


title: Intentional community

text: A survey in the 1995 edition of the "Communities Directory", published by Fellowship for Intentional Community (FIC), reported that 54 percent of the communities choosing to list themselves were rural, 28 percent were urban, 10 percent had both rural and urban sites, and 8 percent did not specify.


title: Intentional community

text: The most common form of governance in intentional communities is democratic (64 percent), with decisions made by some form of consensus decision-making or voting. A hierarchical or authoritarian structure governs 9 percent of communities, 11 percent are a combination of democratic and hierarchical structure, and 16 percent do not specify.


title: Intentional community

text: The central characteristics of communes, or core principles that define communes, have been expressed in various forms over the years. The term "communitarian" was invented by the Suffolk-born radical John Goodwyn Barmby, subsequently a Unitarian minister.


title: Intentional community

text: At the start of the 1970s, "The New Communes" author Ron E. Roberts classified communes as a subclass of a larger category of Utopias. He listed three main characteristics: first, egalitarianism – that communes specifically rejected hierarchy or graduations of social status as being necessary to social order. Second, human scale – that members of some communes saw the scale of society as it was then organized as being too industrialized (or factory sized) and therefore unsympathetic to human dimensions. And third, that communes were consciously anti-bureaucratic.


title: Intentional community

text: Twenty five years later, Dr. Bill Metcalf, in his edited book "Shared Visions, Shared Lives" defined communes as having the following core principles: the importance of the group as opposed to the nuclear family unit, a "common purse", a collective household, group decision making in general and intimate affairs. Sharing everyday life and facilities, a commune is an idealized form of family, being a new sort of "primary group" (generally with fewer than 20 people although there are examples of much larger communes). Commune members have emotional bonds to the whole group rather than to any sub-group, and the commune is experienced with emotions which go beyond just social collectivity.


title: Intentional community

text: With the simple definition of a commune as an intentional community with 100% income sharing, the online directory of the Fellowship for Intentional Community (FIC) lists 222 communes worldwide (28 January 2019). Some of these are religious institutions such as abbeys and monasteries. Others are based in anthroposophic philosophy, including Camphill villages that provide support for the education, employment, and daily lives of adults and children with developmental disabilities, mental health problems or other special needs. Many communes are part of the New Age movement.


title: Intentional community

text: Many cultures naturally practice communal or tribal living, and would not designate their way of life as a planned 'commune' per se, though their living situation may have many characteristics of a commune.


title: Intentional community

text: In Australia, many intentional communities started with the hippie movement and those searching for social alternatives to the nuclear family. One of the oldest continuously running communities is called "Moora Moora Co-operative Community" with about 47 members (Oct 2021). Located at the top of Mount Toolebewong, 65km east of Melbourne, Victoria at an altitude of 600–800 m, this community has been entirely off the electricity grid since its inception in 1974. Founding members still resident include Peter and Sandra Cock.


title: Intentional community

text: In Germany, a large number of the intentional communities define themselves as communes and there is a network of political communes called "Kommuja" with about 30 member groups (May 2009). Germany has a long tradition of intentional communities going back to the groups inspired by the principles of "Lebensreform" in the 19th century. Later, about 100 intentional communities were started in the Weimar Republic after World War I; many had a communal economy. In the 1960s, there was a resurgence of communities calling themselves communes, starting with the Kommune 1 in Berlin, followed by Kommune 2 (also Berlin) and Kommune 3 in Wolfsburg.


title: Intentional community

text: Kibbutzim in Israel, (sing., kibbutz) are examples of officially organized communes, the first of which were based on agriculture. Other Israeli communities are Neve Shalom, Kvutza, Yishuv Kehilati, Moshavim and Kfar No'ar. Today, there are dozens of urban communes growing in the cities of Israel, often called urban kibbutzim. The urban kibbutzim are smaller and more anarchist. Most of the urban communes in Israel emphasize social change, education, and local involvement in the cities where they live. Some of the urban communes have members who are graduates of zionist-socialist youth movements, like HaNoar HaOved VeHaLomed, HaMahanot HaOlim and Hashomer Hatsair.


title: Intentional community

text: In 1831 John Vandeleur (a landlord) established a commune on his Ralahine Estate at Newmarket-on-Fergus, Co. Clare. Vandeleur asked Edward Thomas Craig, an English socialist, to formulate rules and regulations for the commune. It was set up with a population of 22 adult single men, 7 married women and their 7 husbands, 5 single women, 4 orphan boys and 5 children under the age of 9 years. No money was employed, only credit notes which could be used in the commune shop. All occupants were committed to a life with no alcohol, tobacco, snuff or gambling. All were required to work for 12 hours a day during the summer and from dawn to dusk in winter. The social experiment prospered for a time and 29 new members joined. However, in 1833 the experiment collapsed due to the gambling debts of John Vandeleur. The members of the commune met for the last time on 23 November 1833 and placed on record a declaration of "the contentment, peace and happiness they had experienced for two years under the arrangements introduced by Mr. Vandeleur and Mr. Craig and which through no fault of the Association was now at an end".


title: Intentional community

text: In imperial Russia, the vast majority of Russian peasants held their land in communal ownership within a "mir" community, which acted as a village government and a cooperative. The very widespread and influential pre-Soviet Russian tradition of Monastic communities of both sexes could also be considered a form of communal living. After the end of communism in Russia, monastic communities have again become more common, populous and, to a lesser degree, more influential in Russian society. Various patterns of Russian behavior — (толока), (помочи), (артель) — are also based on communal ("мирские") traditions.


title: Intentional community

text: In 1991, Afrikaners in South Africa founded the controversial Afrikaner-only town of Orania, with the goal of creating a stronghold for the Afrikaner minority group, the Afrikaans language and the Afrikaner culture. By 2022, the population was 2,500. The town was experiencing rapid growth and the population had climbed by 55% from 2018. They favour a model of strict Afrikaner self-sufficiency and have their own currency, bank, local government and only employ Afrikaners.


title: Intentional community

text: A 19th century advocate and practitioner of communal living was the utopian socialist John Goodwyn Barmby, who founded a Communist Church before becoming a Unitarian minister.


title: Intentional community

text: The Simon Community in London is an example of social cooperation, made to ease homelessness within London. It provides food and religion and is staffed by homeless people and volunteers. Mildly nomadic, they run street "cafés" which distribute food to their known members and to the general public.


title: Intentional community

text: The Bruderhof has three locations in the UK. In Glandwr, near Crymych, Pembrokeshire, a co-op called Lammas Ecovillage focuses on planning and sustainable development. Granted planning permission by the Welsh Government in 2009, it has since created 9 holdings and is a central communal hub for its community. In Scotland, the Findhorn Foundation founded by Peter and Eileen Caddy and Dorothy Maclean in 1962 is prominent for its educational centre and experimental architectural community project based at The Park, in Moray, Scotland, near the village of Findhorn.


title: Intentional community

text: The Findhorn Ecovillage community at The Park, Findhorn, a village in Moray, Scotland, and at Cluny Hill in Forres, now houses more than 400 people.


title: Intentional community

text: Historic agricultural examples include the Diggers settlement on St George's Hill, Surrey during the English Civil War and the Clousden Hill Free Communist and Co-operative Colony near Newcastle upon Tyne during the 1890s.


title: Intentional community

text: There is a long history of utopian communities in America which led to the rise in the communes of the hippie movement—the "back-to-the-land" ventures of the 1960s and 1970s. One commune that played a large role in the hippie movement was Kaliflower, a utopian living cooperative that existed in San Francisco between 1967 and 1973 built on values of free love and anti-capitalism.


title: Intentional community

text: Andrew Jacobs of "The New York Times" wrote that "after decades of contraction, the American commune movement has been expanding since the mid-1990s, spurred by the growth of settlements that seek to marry the utopian-minded commune of the 1960s with the American predilection for privacy and capital appreciation." The Fellowship for Intentional Community (FIC) is the best source for listings of and more information about communes in the United States.


title: Intentional community

text: While many American communes are short lived, some have been in operation for over 50 years. The Bruderhof was established in the US in 1954, Twin Oaks in 1967 and Koinonia Farm in 1942. Twin Oaks is a rare example of a non-religious commune surviving for longer than 30 years.


The Protestant Ethic and the Spirit of Capitalism () is a book written by Max Weber, a German sociologist, economist, and politician. Begun as a series of essays, the original German text was composed in 1904 and 1905, and was translated into English for the first time by American sociologist Talcott Parsons in 1930. It is considered a founding text in economic sociology and a milestone contribution to sociological thought in general.


title: The Protestant Ethic and the Spirit of Capitalism

text: In the book, Weber wrote that capitalism in Northern Europe evolved when the Protestant (particularly Calvinist) ethic influenced large numbers of people to engage in work in the secular world, developing their own enterprises and engaging in trade and the accumulation of wealth for investment. In other words, the Protestant work ethic was an important force behind the unplanned and uncoordinated emergence of modern capitalism. In his book, apart from Calvinists, Weber also discusses Lutherans (especially Pietists, but also notes differences between traditional Lutherans and Calvinists), Methodists, Baptists, Quakers, and Moravians (specifically referring to the Herrnhut-based community under Count von Zinzendorf's spiritual lead).


text: In 1998, the International Sociological Association listed this work as the fourth most important sociological book of the 20th century, after Weber's "Economy and Society", Mills' "The Sociological Imagination", and Merton's "Social Theory and Social Structure". It is the 8th most cited book in the social sciences published before 1950.


text: Although not a detailed study of Protestantism but rather an introduction to Weber's later studies of interaction between various religious ideas and economics ("" 1915, "" 1916, and "Ancient Judaism" 1917), "The Protestant Ethic and the Spirit of Capitalism" argues that Puritan ethics and ideas influenced the development of capitalism. The 'spirit of capitalism' does not refer to the spirit in the metaphysical sense but rather a set of values, the spirit of hard work and progress.


text: Religious devotion, Weber argues, is usually accompanied by a rejection of worldly affairs, including the pursuit of wealth and possessions. To illustrate his theory, Weber quotes the ethical writings of Benjamin Franklin:


text: Weber notes that this is not a philosophy of mere greed, but a statement laden with moral language. Indeed, Franklin claims that God revealed the usefulness of virtue to him.


text: The Reformation profoundly affected the view of work, dignifying even the most mundane professions as adding to the common good and thus blessed by God, as much as any "sacred" calling (German: ). A common illustration is that of a cobbler, hunched over his work, who devotes his entire effort to the praise of God.


text: To emphasize the work ethic in Protestantism relative to Catholics, he notes a common problem that industrialists face when employing precapitalist laborers: Agricultural entrepreneurs will try to encourage time spent harvesting by offering a higher wage, with the expectation that laborers will see time spent working as more valuable and so engage it longer. However, in precapitalist societies this often results in laborers spending "less" time harvesting. Laborers judge that they can earn the same, while spending less time working and having more leisure. He also notes that societies having more Protestants are those that have a more developed capitalist economy.


text: It is particularly advantageous in technical occupations for workers to be extremely devoted to their craft. To view the craft as an end in itself, or as a "calling" would serve this need well. This attitude is well-noted in certain classes which have endured religious education, especially of a Pietist background.


text: He defines the spirit of capitalism as the ideas and "esprit" that favour the rational pursuit of economic gain: "We shall nevertheless provisionally use the expression 'spirit of capitalism' for that attitude which, "in the pursuit of a calling []", strives systematically for profit for its own sake in the manner exemplified by Benjamin Franklin."


text: Weber points out that such a spirit is not limited to Western culture if one considers it as the attitude of individuals, but that such individuals – heroic entrepreneurs, as he calls them – could not by themselves establish a new economic order (capitalism). He further noted that the spirit of capitalism could be divorced from religion, and that those passionate capitalists of his era were either passionate against the Church or at least indifferent to it. Desire for profit with minimum effort and seeing work as a burden to be avoided, and doing no more than what was enough for modest life, were common attitudes. As he wrote in his essays:


text: After defining the "spirit of capitalism," Weber argues that there are many reasons to find its origins in the religious ideas of the Reformation. Many others like William Petty, Montesquieu, Henry Thomas Buckle, John Keats have noted the affinity between Protestantism and the development of commercialism.


text: Weber shows that certain branches of Protestantism had supported worldly activities dedicated to economic gain, seeing them as endowed with moral and spiritual significance. This recognition was not a goal in itself; rather they were a byproduct of other doctrines of faith that encouraged planning, hard work and self-denial in the pursuit of worldly riches.


text: Weber traced the origins of the Protestant ethic to the Reformation, though he acknowledged some respect for secular everyday labor as early as the Middle Ages. The Roman Catholic Church assured salvation to individuals who accepted the church's sacraments and submitted to the clerical authority. However, the Reformation had effectively removed such assurances. From a psychological viewpoint, the average person had difficulty adjusting to this new worldview, and only the most devout believers or "religious geniuses" within Protestantism, such as Martin Luther, were able to make this adjustment, according to Weber.


text: In the absence of such assurances from religious authority, Weber argued that Protestants began to look for other "signs" that they were saved. Calvin and his followers taught a doctrine of double predestination, in which from the beginning God chose some people for salvation and others for damnation. The inability to influence one's own salvation presented a very difficult problem for Calvin's followers, who, in Weber's view, considered it an absolute duty to believe that one was chosen for salvation and to dispel any doubt about that: lack of self-confidence was evidence of insufficient faith and a sign of damnation. So, self-confidence took the place of priestly assurance of God's grace.


text: Worldly success became one measure of that self-confidence. Luther made an early endorsement of Europe's emerging divisions. Weber identifies the applicability of Luther's conclusions, noting that a "vocation" from God was no longer limited to the clergy or church, but applied to any occupation or trade. Weber had always detested Lutheranism for the servility it inspired toward the bureaucratic state. When he discussed it in the "Protestant Ethic", he used Lutheranism as the chief example of the "unio mystica" that contrasted sharply with the ascetic posture. Later he would associate "Luther, the symbolic exponent of bureaucratic despotism, with the ascetic hostility to Eros — an example of Weber's sporadic tendency to link together bureaucratic and ascetic modes of life and to oppose both from mystical and aristocratic perspectives."


text: However, Weber saw the fulfillment of the Protestant ethic not in Lutheranism, which was too concerned with the reception of divine spirit in the soul, but in Calvinistic forms of Christianity. The trend was carried further still in Pietism. The Baptists diluted the concept of the calling relative to Calvinists, but other aspects made its congregants fertile soil for the development of capitalism—namely, a lack of paralyzing ascetism, the refusal to accept state office and thereby develop politically, and the doctrine of control by conscience which caused rigorous honesty.


text: The manner in which this dilemma was resolved, Weber argued, was the investment of this money, which gave an extreme boost to nascent capitalism.


text: By the time Weber wrote his essay, he believed that the religious underpinnings of the Protestant ethic had largely gone from society. He cited the writings of Benjamin Franklin, which emphasized frugality, hard work and thrift, but were mostly free of spiritual content. Weber also attributed the success of mass production partly to the Protestant ethic. Only after expensive luxuries were disdained could individuals accept the uniform products, such as clothes and furniture, that industrialization offered.


text: In his conclusion to the book, Weber lamented that the loss of religious underpinning to capitalism's spirit has led to a kind of involuntary servitude to mechanized industry.


text: Weber maintained that while Puritan religious ideas had significantly impacted the development of economic systems in Europe and United States, there were other factors in play, as well. They included a closer relationship between mathematics and observation, the enhanced value of scholarship, rational systematization of government administration, and an increase in entrepreneurship ventures. In the end, the study of Protestant ethic, according to Weber, investigated a part of the detachment from magic, that that could be seen as a unique characteristic of Western culture.


text: In the final endnotes Weber states that he abandoned research into Protestantism because his colleague Ernst Troeltsch, a professional theologian, had begun work on "The Social Teachings of the Christian Churches and Sects". Another reason for Weber's decision was that Troeltsch's work already achieved what he desired in that area, which is laying groundwork for comparative analysis of religion and society. Weber moved beyond Protestantism with his research but would continue research into sociology of religion within his later works (the study of Judaism and the religions of and ).


text: This book is also Weber's first brush with the concept of rationalization. His idea of modern capitalism as growing out of the religious pursuit of wealth meant a change to a rational means of existence, wealth. That is to say, at some point the Calvinist rationale informing the "spirit" of capitalism became unreliant on the underlying religious movement behind it, leaving only rational capitalism. In essence then, Weber's "Spirit of Capitalism" is effectively and more broadly a Spirit of Rationalization.


text: The essay can also be interpreted as one of Weber's criticism of Karl Marx and his theories. While Marx's historical materialism held that all human institutions – including religion – were based on economic foundations, many have seen "The Protestant Ethic" as turning this theory on its head by implying that a religious movement fostered capitalism, not the other way around.


text: Other scholars have taken a more nuanced view of Weber's argument. Weber states in the closing of this essay, "it is, of course, not my aim to substitute for a one-sided materialistic an equally one-sided spiritualistic causal interpretation of culture and history. Each is equally possible, but each if it does not serve as the preparation, but as the conclusion of an investigation, accomplishes equally little in the interest of historical truth." Weber's argument can be understood as an attempt to deepen the understanding of the cultural origins of capitalism, which does not exclude the historical materialist origins described by Marx: modern capitalism emerged from an elective affinity of 'material' and 'ideal' factors.


text: Weber's causal claim that the Protestant ethic led to capitalism has been criticized for endogeneity problems and case selection problems. Rather than Protestantism leading to capitalism, it may be the case that individuals and communities who were more prone to capitalism were also more likely to adopt Protestantism.


text: The economist and historian Henryk Grossman criticises Weber's analysis on two fronts, firstly with reference to Marx's extensive work which showed that the stringent legal measures taken against poverty and vagabondage was a reaction to the massive population shifts caused by factors such as the enclosure of the commons. And, secondly, in Grossman's own work showing how this "bloody legislation" against those who had been put off their land was effected across Europe and especially in France. For Grossman this legislation, the outlawing of idleness and the poorhouses they instituted physically forced people from serfdom into wage-labor. For him, this general fact was not related to Protestantism and so capitalism came largely by force and not by any vocational training regarding an inner-worldliness of Protestantism. However, it is possible that the Protestant "work ethic" reinforced or legitimized these legal measures within a larger cultural context.


text: In a paper published on 10 November 2009, Harvard economist Davide Cantoni tested Weber's Protestant hypothesis using population and economic growth in second-millennium Germany as the data set, with negative results. Cantoni writes:


text: However, Cantoni uses city size, and not relative real wage growth, which was the Weber thesis, as his "main dependent variable" (Cantoni, 2).


text: Other recent scholarship continues to find valid Protestant Ethic effects both in historical and contemporary development patterns.


text: Daron Acemoglu and James A. Robinson in their book "Why Nations Fail" reject the relationship between economic progress and Protestantism writing:


text: Hector Menteith Robertson, in his book "Aspects of Economic Individualism" (1933), argued against the historical and religious claims of Weber. Robertson pointed out that capitalism began to flourish not in Britain, but in 14th century Italy, so the rise of capitalism cannot be attributed to Adam Smith, the Protestant Reformation, etc. Robertson goes further, and states that what happened in Britain was rather a retrogression from what was achieved in Italy centuries earlier.


text: Robertson shows that Adam Smith and David Ricardo did not found economic science "de novo". In fact, liberal economic theory was developed by French and Italian Catholics, who were influenced by the Scholastics. The British economic thought was rather a step backwards since it espoused the labor theory of value, which had already been proved incorrect by the School of Salamanca.


text: It has recently been suggested that Protestantism has indeed influenced positively the capitalist development of respective social systems not so much through the "Protestant ethics" but rather through the promotion of literacy. Sascha Becker and Ludger Wossmann of the University of Munich showed that literacy levels differing in religious areas can sufficiently explain the economic gaps cited by Weber. The results were supported even under a concentric diffusion model of Protestantism using distance from Wittenberg as a model.


text: Weber's conclusion has also been criticized for ignoring the ethnic dimensions. Weber focused on religion, but ignored the fact that Germany contained a large Polish minority (due to the partitions of Poland); and Poles were primarily Catholic and Germans, Protestant. As such, scholars have suggested that what Weber observed was in fact "anti-Polish discrimination" visible in the different levels of income, savings and literacy between Germans and Poles.


text: The noted French historian Fernand Braudel, considered one of the greatest of the modern historians, vigorously criticized Weber's theory, noting its lack of foundation and veracity, stating:


text: In 1958, American sociologist Gerhard Lenski conducted an empirical inquiry into "religion's impact on politics, economics, and family life" in the Detroit, Mich., area. It revealed, among other insights, that there were significant differences between Catholics on the one hand and (white) Protestants and Jews on the other hand with respect to economics and the sciences. Lenski's data supported basic hypotheses of Weber's work "The Protestant Ethic and the Spirit of Capitalism". According to Lenski, "the contribution of Protestantism to material progress have been largely unintended by-products of certain distinctive Protestant traits. This was a central point in Weber's theory." Lenski noted that more than a hundred years prior to Weber, John Wesley, one of the founders of the Methodist church, had observed that "diligence and frugality" made Methodists wealthy. "In an early era, Protestant asceticism and dedication to work, as noted both by Wesley and Weber, seem to have been important patterns of action contributing to economic progress. Both facilitated the accumulation of capital, so critically important to the economic growth and development of nations."


text: German theologian Friedrich Wilhelm Graf notes: "Sociologists of religion like Peter L. Berger and David Martin have interpreted the Protestant revolution in Latin America as implicit support of basic elements of Weber's thesis. [...] At any rate, many pious persons there interpret their transition from the Roman Catholic church to Protestant Pentecostal congregations in terms of a moral idea that promises long-term economic gains through strong innerworldly asceticism. The strict ascetic self-discipline that has been successfully institutionalized in the Pentecostal congregations, the readiness to work more and with greater effort and to take less leisurely attitudes lead many Pentecostal Christians to believe that their new faith in God is supported by their economic successes."


title: Terraforming of Mars

text: The terraforming of Mars or the terraformation of Mars is a hypothetical procedure that would consist of a planetary engineering project or concurrent projects, with the goal of transforming Mars from a planet hostile to terrestrial life to one that can sustainably host humans and other lifeforms free of protection or mediation. The process would presumably involve the rehabilitation of the planet's extant climate, atmosphere, and surface through a variety of resource-intensive initiatives, and the installation of a novel ecological system or systems.


title: Terraforming of Mars

text: Justifications for choosing Mars over other potential terraforming targets include the presence of water and a geological history that suggests it once harbored a dense atmosphere similar to Earth's. Hazards and difficulties include low gravity, low light levels relative to Earth's, and the lack of a magnetic field.


title: Terraforming of Mars

text: Disagreement exists about whether current technology could render the planet habitable. Reasons for objecting to terraforming include ethical concerns about terraforming and the considerable cost that such an undertaking would involve. Reasons for terraforming the planet include allaying concerns about resource use and depletion on Earth and arguments that the altering and subsequent or concurrent settlement of other planets decreases the odds of humanity's extinction.


title: Terraforming of Mars

text: Future population growth, demand for resources, and an alternate solution to the Doomsday argument may require human colonization of bodies other than Earth, such as Mars, the Moon, and other objects. Space colonization would facilitate harvesting the Solar System's energy and material resources.


title: Terraforming of Mars

text: In many aspects, Mars is the most Earth-like of all the other planets in the Solar System. It is thought that Mars had a more Earth-like environment early in its geological history, with a thicker atmosphere and abundant water that was lost over the course of hundreds of millions of years through atmospheric escape. Given the foundations of similarity and proximity, Mars would make one of the most plausible terraforming targets in the Solar System.


title: Terraforming of Mars

text: Side effects of terraforming include the potential displacement or destruction of indigenous life, even if microbial, if such life exists.


title: Terraforming of Mars

text: The Martian environment presents several terraforming challenges to overcome and the extent of terraforming may be limited by certain key environmental factors. Here is a list of some of the ways in which Mars differs from Earth, which terraforming seeks to address:


title: Terraforming of Mars

text: Mars doesn't have an intrinsic global magnetic field, but the solar wind directly interacts with the atmosphere of Mars, leading to the formation of a magnetosphere from magnetic field tubes. This poses challenges for mitigating solar radiation and retaining an atmosphere.


title: Terraforming of Mars

text: The lack of a magnetic field, its relatively small mass, and its atmospheric photochemistry, all would have contributed to the evaporation and loss of its surface liquid water over time. Solar wind–induced ejection of Martian atmospheric atoms has been detected by Mars-orbiting probes, indicating that the solar wind has stripped the Martian atmosphere over time. For comparison, while Venus has a dense atmosphere, it has only traces of water vapor (20 ppm) as it lacks a large, dipole induced, magnetic field.


title: Terraforming of Mars

text: Earth's ozone layer provides additional protection. Ultraviolet light is blocked before it can dissociate water into hydrogen and oxygen.


title: Terraforming of Mars

text: The surface gravity on Mars is 38% of that on Earth. It is not known if this is enough to prevent the health problems associated with weightlessness.