The final building block in a critical global missile warning system operated by the Pentagon took flight on Friday atop a United Launch Alliance Atlas V rocket blasting off into the night over Florida’s Cape Canaveral. Destined for a gap in the current constellation of state-of-the-art missile warning satellites, the fourth SBIRS spacecraft will relieve the last of the older DSP satellites and establish a global constellation that can keep watch over anything from a tactical short-range missile to inbound ICBM threats.

Atlas V – flying in its “lopsided” configuration with only a single Solid Rocket Booster – leapt of its SLC-41 launch pad at 0:48 UTC on Saturday, 7:48 p.m. local time on Friday. Departing Cape Canaveral to the south-east, Atlas V dropped the lone booster into the Atlantic 140 seconds into the flight while the Russian-built RD-180 engine fired until the T+4-minute mark before handing off to the trusted Centaur Upper Stage. The final push into orbit was up to Centaur’s RL-10C engine, first firing the stack into a Low Earth Parking Orbit before giving SBIRS GEO-4 a second boost to lift the high point of its orbit and send the spacecraft on its way 43 minutes after launch.

United Launch Alliance confirmed the successful outcome of Friday night’s mission shortly after the 4.5-metric-ton satellite sailed off from the Centaur upper stage which was then to conduct a deorbit burn to remove itself from orbit as a debris mitigation measure.

This marked ULA’s second launch of the year, coming on the heels of last week’s Delta IV launch also in support of U.S. National Security. For Atlas V, the mission opened a year that could see as many as eight missions per the current ULA manifest, including a trip toward Mars with NASA’s InSight Lander and the first launch without a payload fairing when flying with Boeing’s Starliner spacecraft for the first time in the second half of 2018.

The 75th Atlas V mission was tasked with deploying the fourth satellite for the Space Based Infrared System (SBIRS) – a constellation of dedicated satellites in Geostationary Orbit and hosted sensors in highly elliptical orbits to provide a global missile-tracking capability through eagle-eyed infrared sensors.

Considered one of the Pentagon’s most critical space-based defence assets, the multi-billion Dollar SBIRS constellation is designed to detect and track missile launches to deliver timely warnings of any imminent threat to the U.S. homeland, deployed armed forces and allied nations while also providing crucial data guiding a missile defence response.

Built as a successor to the Defence Support Program that provided missile tracking since the early days of the Cold War, SBIRS has to deal with a changed playing field and must be capable of not only detecting the powerful ICBMs operated by only seven countries, but also short-range missiles used abundantly across the globe.

The early detection of incoming missiles is of utmost importance when attempting to intercept the attack before it reaches its destination. Initial missile warning systems established in the 1950s relied on ground-based radars with very limited range, providing only very short warning lead times. As the exploitation of space became a reality in the 1960s, U.S. leadership immediately recognized the importance of establishing a space-based missile warning system to increase warning times.

MIDAS, the Missile Defense Alarm System, launched a number of satellites toward Low Earth Orbit in the 60s but never reached operational strength due to a high number of launch and in-orbit failures as space technology had not yet reached the level of maturity for the operation of complex systems. However, MIDAS was successful in demonstrating that the infrared signatures of missiles could indeed be detected from orbit – freeing up additional resources to move development forward.

The Defence Support Program (DSP) was inaugurated in 1970 and, over 35 years, went through three generations of satellites operated from Geostationary Orbit to provide global missile-tracking capabilities via a windshield-wiper-type sensor system that swept out large viewing sectors as the satellites spun around their central axis. Given their use of antiquated sensors, DSP satellites could only pick up large missiles and only after they ascended above much of Earth’s atmosphere due to infrared attenuation by the atmosphere.

Work on SBIRS as a successor to DSP formally started in 1996 in response to changing threats that necessitated an integrated system capable of detecting all types of missiles and cutting warning times in half compared to the DSP-based architecture. Lockheed Martin serves as the prime contractor for the SBIRS-GEO satellites while Northrop Grumman developed and built the SBIRS infrared-sensing instruments, including those flying as hosted instruments on classified NRO missions in highly elliptical orbits to patch up a blind area in the high-latitude regions and monitor potential threats overflying the North Pole.

The SBIRS-GEO satellites utilize Lockheed’s A2100 satellite platform and each weighs around 4,500 Kilograms, built for at least 12 years of service and comprising a pair of power-generating solar arrays and a large sun shield for the sensitive sensors. Each GEO satellite is outfitted with a pair of instruments – a scanning and a staring sensor, both sensitive in three infrared bands covering the short- and mid-wave wavelengths and a see-to-ground channel to spot infrared signatures from ground level up.

>>Space Based Infrared System Overview

The scanning sensor progressively scans the entire disk of Earth visible to the satellite to identify ICBM launches at a fast revisit rate while the staring sensor is either primed on a single location of interest or steps between multiple areas to spot faint & short-duration signatures from short-range missiles.

Given their sensitivity, the SBIRS satellites can also spot other infrared events such as wildfires and volcanic eruptions and they are called upon for pin-pointing re-entering space debris as they burn up in Earth’s atmosphere. See-to-ground infrared-sensing is also beneficial to other intelligence-gathering entities outside of missile detection as examining human-made infrared emissions can provide insight into activities on foreign territory not visible to optical reconnaissance & radar satellites.



As one of the most critical U.S. defence programs in space, SBIRS was extended in 2014 and two additional satellites were ordered from Lockheed Martin to launch in the 2020s to ensure SBIRS-quality services can continue through the end of the next decade.

The payload of AV-076 is the fourth dedicated SBIRS satellite, joining SBIRS-GEO satellites launched in 2011, 2013 and 2017, as well as four HEO sensors deployed on National Reconnaissance Office satellites launched in 2006, 08, 14 and last September. SBIRS GEO-4 is in fact the third SBIRS production vehicle that finished assembly and testing prior to the spacecraft launched in January 2017 but was left in storage while SV-4 proceeded straight from finishing manufacture to the launch site, eliminating the cost of SV-3 and SV-4 swapping places.

Unlike its predecessors that flew on the basic Atlas V 401 configuration, SBIRS GEO-4 launched atop an Atlas V 411 sporting a single Solid Rocket Booster in a bid to increase the rocket’s performance and provide fuel margin for a targeted deorbit burn by the Centaur upper stage. This comes as part of a U.S. Air Force initiative to demonstrate responsibility in the area of space debris, removing upper stages from orbit whenever possible – even if that comes at the additional cost of switching to a more powerful launch vehicle version.

However, the addition of the booster not only provided fuel reserves for the Centaur deorbit but also increased performance up the hill, allowing additional propellants on Centaur to be re-allocated from the Parking Orbit insertion to the apogee boost maneuver to increase the plane change into a lower-inclination orbit and drop SBIRS GEO-4 off closer to its operational orbit.

>>Atlas V 411 Launch Vehicle Overview

The countdown to the 125th United Launch Alliance mission started at 17:58 UTC on Friday when controllers at the Atlas Spaceflight Operations Center began the process of activating the Atlas V rocket for a multi-hour testing campaign. Engineers departed the launch complex three hours prior to the opening of the day’s launch window and Atlas V entered cryogenic tanking when the countdown resumed after a built-in hold at T-2 hours.

Over the course of one and a half hours, Atlas V received 185,500 liters of Liquid Oxygen on its first stage while the second stage was loaded with 15,700 liters of the -183°C oxidizer plus 48,100 liters of -253°C Liquid Hydrogen. The Common Core Booster had received its dose of fuel after Wednesday’s rollout in the form of 94,600 liters of Rocket Propellant 1.

All Atlas V and spacecraft launch controllers called out a GO for launch and the countdown was switched to automatic mode at the T-4-minute mark to put the rocket through a highly choreographed series of steps to get ready for ignition and liftoff at the top of the night’s 40-minute launch window.

The two-chamber RD-180 main engine roared to life three seconds before clocks hit zero to throttle up to a liftoff thrust of 392 metric-ton force under close supervision by computers. Atlas V rose from its launch pad upon ignition of its Solid Rocket Booster at 0:48:00 UTC with a total thrust of 564.5 metric tons, climbing vertically for only seven seconds before beginning its roll and pitch maneuver to get aligned with a 96-degree launch azimuth taking the vehicle to the south east.

The two-chamber RD-180 switched to active propellant utilization and, throughout the early portion of the flight, was tasked with compensating the off-axis thrust from the booster. Flying right and true, Atlas V passed the speed of sound just 58 seconds after launch followed 13 seconds later by Maximum Dynamic Pressure as the rocket powered through the dense atmosphere.

Thrust on the lone Aerojet Rocketdyne booster tailed off 94 seconds into the flight when it exhausted its 41,000-Kilogram supply of solid propellant. Separation did not occur until T+2 minutes and 20 seconds to ensure the 17-meter long SRB would depart the vehicle in favorable aerodynamic conditions – a result of the slanted nose cone shape of the AJ60 booster on the Atlas V.

Heading on powered by the RD-180 alone, Atlas V switched to active guidance to process navigation data in order to modify its flight profile to meet the precise cutoff targets. Burning 1,150 Kilograms of propellant per second, RD-180 delivered a thrust of 422 metric-ton force when flying through the rarefied upper layers of the atmosphere, entering a gradual throttle-down to limit acceleration on the vehicle toward the end of its burn.

BECO, Booster Engine Cutoff, was marked at T+4 minutes and 3 seconds and the spent 32.5-meter long first stage separated six seconds later, pulling away by firing retrorockets.

Ten seconds after staging, the Centaur ignited its 10,400-Kilogram-force RL-10C engine to boost the stack into a Parking Orbit. Another ten seconds later, Atlas V split open and jettisoned its payload fairing halves – having crossed the boundary of space where aerodynamic forces were no-longer a danger to the SBIRS satellite.

Taking advantage of the work done earlier in flight by the SRB, Centaur only had to fire nine minutes and 30 seconds to reach the desired Parking Orbit – around 94 seconds shorter than for previous SBIRS deliveries – saving precious fuel for the second burn and the deorbit maneuver. Centaur concluded its first burn just shy of T+14 minutes, achieving an orbit of 176 by 497 Kilometers at an inclination of 26.2 degrees for a coast phase of ten and a half minutes to continue on its south-easterly path so that the second burn could occur around the equator.

Re-start of the RL-10C engine was called out 24 minutes and 15 seconds into the flight and the second burn appeared to meet its planned duration of five minutes and two seconds, tasked with raising the high point of the orbit to match geostationary altitude and firing Centaur out-of-plane to nudge the stack into a less-inclined orbit.

Centaur’s navigation system showed an insertion orbit of 185 by 35,837 Kilometers, 16.88° which compares very favorably to the mission’s target orbit of 185 by 35,851 Kilometers, inclined 16.88°. The additional reduction of the orbit’s inclination by 6.4° compared to previous SBIRS missions will save fuel on the satellite when transitioning into Geostationary Orbit which will be available to support stationkeeping in GEO over an extended mission duration.

Atlas V went back into coast mode after its second burn, passing over Sub-Saharan Africa and the island of Madagascar before heading out over the Indian Ocean. Separation of the SBIRS GEO-4 satellite was confirmed 42.5 minutes into the mission after a smooth climb into Geostationary Transfer Orbit.

Following separation from its launch vehicle, SBIRS-GEO 4 will begin a multi-day sequence firing its Leros main engine to gradually lift itself into Geostationary Orbit. The Air Force did not disclose from where the satellite will operate, but it is fairly certain GEO-4 will take up station to cover the Eastern Pacific and the Americas in order to patch up the last gap in SBIRS-GEO coverage.

The last order of business for Centaur was to be a ten-second retrograde deorbit maneuver one hour and 14 minutes into the mission to set it on a course to a fiery re-entry over the Pacific Ocean with surviving fragments impacting nine hours and 25 minutes after launch.</s>BUCKLEY AIR FORCE BASE, Colo., Jan. 19, 2018 /PRNewswire/ -- The U.S. Air Force's 460th Space Wing is now "talking" with the fourth Space Based Infrared System (SBIRS) Geosynchronous Earth Orbit (GEO) satellite after its successful launch from Cape Canaveral Air Force Station, Florida, earlier this evening.

The Lockheed Martin (NYSE: LMT)-built SBIRS GEO Flight-4 satellite is responding to the Wing's commands as planned. Signal acquisition was confirmed approximately 37 minutes after the satellite's 7:48 p.m. EST launch aboard a United Launch Alliance (ULA) Atlas V rocket.

SBIRS GEO Flight-4 is the latest satellite to join the Air Force's orbiting missile warning constellation equipped with powerful scanning and staring infrared surveillance sensors. The sensors collect data for use by the U.S. military to detect missile launches, support ballistic missile defense, expand technical intelligence gathering and bolster situational awareness on the battlefield. The satellite also completes the initial constellation and allows SBIRS to provide global coverage.

Back on the ground at Buckley Air Force Base, a sophisticated new SBIRS ground control system – also designed by Lockheed Martin – serves as the nerve center for the entire SBIRS satellite constellation and receives large amounts of data from the satellites' powerful sensors. The SBIRS control system and its operators convert this data into actionable reports for defense, intelligence and civil applications.

"SBIRS is the nation's 24-7 global watchman, with infrared eyes ready to detect and deliver early warning and tracking of ballistic missiles. A cornerstone of the nation's missile defense system, SBIRS is proving even more precise and powerful than expected," said Tom McCormick, vice president of Lockheed Martin's Overhead Persistent Infrared systems mission area. "Space is a place to do great things, and we're already improving on SBIRS, upgrading our fifth and sixth SBIRS GEO satellites to our modernized LM 2100 satellite bus at no additional cost to the Air Force. On SBIRS 5 and 6 the Air Force saved $1 billion through improved production and management efficiencies."

In late 2016, Lockheed Martin also completed a major upgrade SBIRS' ground control system. The new "SBIRS Block 10" system includes enhancements like faster data collection times, improved threat detections, and improved target tracking and infrared information to enable troops to see dimmer targets faster. SBIRS Block 10 also provides the Air Force with greater efficiency by consolidating ground control for the legacy Defense Support Program, as well as SBIRS satellites and payloads in GEO and Highly Elliptical Orbits.

Next, the SBIRS GEO Flight-4 will begin transitioning to its final location in geosynchronous orbit, approximately 22,000 miles above the Earth. There, the satellite's solar arrays, light shade and antennas will be deployed to begin on-orbit testing. The satellite will join SBIRS GEO Flights 1, 2 and 3, which were launched in 2011, 2013 and 2017 respectively and continue to meet or exceed performance expectations.

Lockheed Martin manufactured the SBIRS GEO Flight-4 satellite at its Sunnyvale, California, facility. The satellite was delivered to Florida on Oct. 31, 2017.

The SBIRS development team is led by the Remote Sensing Systems Directorate at the U.S. Air Force Space and Missile Systems Center, Los Angeles Air Force Base, California. Lockheed Martin Space, Sunnyvale, California, is the SBIRS prime contractor, with Northrop Grumman Aerospace Systems, Azusa, California, as the payload integrator.

About Lockheed Martin

Headquartered in Bethesda, Maryland, Lockheed Martin is a global security and aerospace company that employs approximately 97,000 people worldwide and is principally engaged in the research, design, development, manufacture, integration and sustainment of advanced technology systems, products and services.</s>ULA Atlas V 411 lights up the night with SBIRS GEO 4 launch

CAPE CANAVERAL, Fla. — United Launch Alliance (ULA) saw its launch window open at 7:48 p.m. Eastern (00:48 GMT on Jan. 20) and soon thereafter sent its Atlas V rocket thundering into the Florida sky. The payload, the fourth geosynchronous satellite in the U.S. Air Force (USAF) Space Based Infrared Sensor (SBIRS) program, is now headed for geosynchronous orbit.

Once its there, it will help enhance USAF’s missile early warning, missile defense, battlefield awareness, as well as technical intelligence.

The Atlas V 411 used for this evening’s launch was an ideal choice for the GEO 4 flight based on its performance (up to 12,323 pounds / 5,590 kg to a geosynchronous transfer orbit / GTO). The 411 variant of the vehicle is comprised of the Atlas common core booster stage and a single Aerojet Rocketdyne-provided asymmetrical solid rocket booster (SRB) for liftoff as well as a four-meter payload fairing and a single RL10C-1 engine on the Centaur upper stage.

At approximately T-3 seconds, the Russian-built NPO Energomash-built kerosene/liquid oxygen RD-180 rocket engine ignited its 860,000 pounds (3,825 kilonewtons) of thrust, followed by the Aerojet Rocketdyne AJ60 SRB, pushing the rocket rapidly away from Space Launch Complex (SLC) 41 at T-0, 7:48 p.m. Eastern Time.

Eighteen seconds off the pad, the Atlas V began its pitch/yaw maneuver to point it in the proper direction for its eventual placement over the Equator. Just over 80 seconds after liftoff, Atlas V powered through Mach 1 and then maximum dynamic pressure ten seconds later.

The Atlas Booster Engine cut off some 243 seconds into flight, with the booster separating from the Centaur upper stage six seconds later. The Centaur’s RL10A upper stage engine ignited ten seconds after booster separation, with the payload fairing jettisoning eight seconds later.

Afterward SBIRS GEO-4 will begin transitioning to its its planned final location in geosynchronous orbit, approximately 22,000 miles (35,406 kilometers) above our world. If everything goes as mission planners hope, the satellite will deploy its solar arrays, antennas and its light shade before it undergoes testing. The spacecraft will join its ‘siblings’ SBIRS GEOs 1, 2 and 3, which were launched in 2011, 2013 and 2017 respectively and continue to meet or exceed performance expectations.

“Meeting the challenge of launching two critical national security missions from opposite coasts within a week, the entire ULA team once again demonstrated its unwavering dedication to 100 percent mission success,” said Laura Maginnis, ULA vice president of Government Satellite Launch via a release issued by ULA. “Thank you to our U.S. Air Force and industry teammates for their outstanding partnership in successfully delivering SBIRS to orbit today.”

While there is no official word on when GEO-4 will begin operations, GEO-3 spent around 65 days circularizing its orbit before reaching its station and starting to collect images of Earth. This positioning effort was followed by a commissioning campaign lasting several months before the USAF declared the satellite operational. The previous two satellites (GEO-1 and -2) took 16 and 35 days, respectively, to circularize their orbits.

The contract for the next two geosynchronous elements for SBIRS, GEO-5 and -6, was signed in 2014. These two spacecraft will use a more advanced Lockheed Martin A2100M spacecraft bus. According to a Space News report, Lockheed Martin expects to have the two satellites completed by 2022.

“SBIRS is the nation’s 24-7 global watchman, with infrared eyes ready to detect and deliver early warning and tracking of ballistic missiles. A cornerstone of the nation’s missile defense system, SBIRS is proving even more precise and powerful than expected,” said Tom McCormick, vice president of Lockheed Martin’s Overhead Persistent Infrared systems mission area. “Space is a place to do great things, and we’re already improving on SBIRS, upgrading our fifth and sixth SBIRS GEO satellites to our modernized LM 2100 satellite bus at no additional cost to the Air Force. On SBIRS 5 and 6 the Air Force saved $1 billion through improved production and management efficiencies.”

The launch had been scheduled to take place on Thursday, Jan. 18. However, due to a ground issue associated with the booster liquid oxygen system, the flight was pushed back 24 hours to this evening.

The weather conditions for tonight’s flight – simply could not have been better with clear, albeit chilly, temperatures providing favorable conditions calculated at being around 90 percent. With weather and no other issues cropping up, Atlas’ lone RD-180 and its lone solid rocket booster cleaved a bright arc through the early evening skies, signaling a successful start to the mission.

“The SBIRS satellites help safeguard the nation’s homeland and deployed forces against the threat of ballistic missile attacks. It is critical to have reliable propulsion systems on every satellite to ensure they maintain a watchful eye and are able to detect a threat at a moment’s notice,” said Eileen Drake, CEO and president of Aerojet Rocketdyne, which provided the Centaur’s rocket engine as well as the AJ-60A solid rocket strap-on motor that was attached to the rocket’s core stage.

ULA’s next scheduled flight is, at present, the flight of an Atlas V 541 with the GOES-S weather satellite for the National Oceanic and Atmospheric Administration (NOAA). That mission is slated to launch on March 1.</s>The United Launch Alliance launched an Atlas V rocket Friday from Cape Canaveral in Florida, United States, and placed a fourth infrared sensing satellite into orbit, as part of the US Air Force missile-detection system.

The liftoff occurred at 7.48pm from a platform of the complex 41 of the space center, and is the US Air Force's fourth Space Based Infrared System (SBIRS) missile-detection satellite.</s>United Launch Alliance launches SBIRS GEO-4 from Cape Canaveral Air Force Station on an Atlas V rocket. Liftoff is set for 7:48 p.m.</s>SACRAMENTO, Calif., Jan. 19, 2018 (GLOBE NEWSWIRE) -- Aerojet Rocketdyne, Inc., a subsidiary of Aerojet Rocketdyne Holdings, Inc. (NYSE:AJRD), played an integral part in today’s launch of the U.S. Air Force’s newest missile warning satellite, including a role in helping to minimize the mission’s impact on Earth’s orbital environment.



The launch of the Space Based Infrared System (SBIRS) Geosynchronous Earth Orbit satellite 4 (GEO Flight-4) aboard a United Launch Alliance (ULA) Atlas V rocket from Cape Canaveral Air Force Station, Florida, featured Aerojet Rocketdyne propulsion systems in all of its phases. The mission differed from previous SBIRS launches aboard the Atlas V rocket in that an Aerojet Rocketdyne AJ-60A solid rocket strap-on motor was used to increase the vehicle’s lifting capability.



The added power from the single AJ-60A reduced the amount of fuel needed by the rocket’s Centaur upper stage to place the Lockheed Martin-built SBIRS GEO Flight-4 satellite into its proper transfer orbit. Once the satellite separated, the Centaur had sufficient fuel left over to propel itself into the ocean, so that it will not pose a collision threat to spacecraft in an increasingly congested orbital environment.

“As space becomes increasingly congested, it is important to recognize propulsion systems play an important role in supporting efforts to minimize orbital congestion that otherwise could hamper future operations,” said Eileen Drake, CEO and president of Aerojet Rocketdyne.

The Centaur is powered by Aerojet Rocketdyne’s RL10C-1 upper-stage engine, which generates 22,890 pounds of thrust. Variants of the RL10 have been in service for more than 50 years on multiple vehicles, including ULA’s current Delta IV, which is used along with the Atlas V to launch the vast majority of U.S. national security satellites.

Both stages of the Atlas V used Aerojet Rocketdyne-supplied helium pressurization tanks, while the company’s 12 MR-106 hydrazine thrusters provided roll, pitch and yaw control, as well as settling burns, for the Centaur’s phase of the mission.

Aerojet Rocketdyne’s propulsion products were not limited to the launch vehicle. The SBIRS GEO Flight-4 satellite is equipped with 18 Aerojet Rocketdyne hydrazine thrusters that will maintain its orbit and orientation during a mission lasting up to 12 or more years. These include 12 MR-103 thrusters providing .2 pounds of thrust each, and six MR-106L hydrazine thrusters, each providing 5 pounds of thrust. In addition to maintaining the satellite in its orbital position, these thrusters provide attitude control during orbit raising as well as the boost needed to decommission the satellite at the end of its service life.

Built by Lockheed Martin Space, SBIRS consists of a network of satellites in geosynchronous orbit, sensors in highly elliptical orbit and a sophisticated ground control system. The SBIRS’ primary mission is to provide timely warning of missile launches throughout the world. Other SBIRS missions include missile defense, battlespace awareness and technical intelligence gathering. Once it completes on-orbiting testing, GEO Flight-4 will round out the initial SBIRS constellation, providing global coverage.

“The SBIRS satellites help safeguard the nation’s homeland and deployed forces against the threat of ballistic missile attacks. It is critical to have reliable propulsion systems on every satellite to ensure they maintain a watchful eye and are able to detect a threat at a moment’s notice,” added Drake.

Aerojet Rocketdyne is an innovative company delivering solutions that create value for its customers in the aerospace and defense markets. The company is a world-recognized aerospace and defense leader that provides propulsion and energetics to the space, missile defense and strategic systems, tactical systems and armaments areas, in support of domestic and international markets. Additional information about Aerojet Rocketdyne can be obtained by visiting our websites at www.Rocket.com and www.AerojetRocketdyne.com.</s>Jan. 19 (UPI) -- United Launch Alliance launched a missile defense satellite into low-Earth orbit Friday, one day after scrubbing the mission.

ULA's Atlas V rocket blasted off from Space Launch Complex-41 at Florida's Cape Canaveral Air Force Station.

Friday's mission continues the ongoing modernization of the United States' missile monitoring technology. The payload includes GEO-4, the fourth satellite in the Space-Based Infrared System, or SBIRS.

Lockheed Martin was responsible for the design and construction of GEO-4, while the U.S. Air Force manages the missile defense system.

Thursday's launch was delayed "due to a ground issue associated with the booster liquid oxygen system," ULA wrote on Twitter.

The SBIRS GEO Flight-4 satellite was the fourth to be launched by ULA and the Air Force.

According to Tom McCormick, vice president for Lockheed Martin's overhead persistent infrared systems mission area, the satellite completes the original baseline constellation, allowing SBIRS to finally offer worldwide coverage.

The improved technology infrared-tracking technology offered by SBIRS will help the Air Force identify dimmer targets. Officials said the U.S. military must continually improve the system's capabilities to detect missiles designed to an undetectably small a heat signature.

The SBIRS satellites will collect data and relay it to an Air Force command center where it will be used to issue missile warnings and inform decisions related to missile defense systems, as well as improve battle space awareness and technical intelligence.</s>Miami, USA, Jan 19 (EFE).- The United Launch Alliance launched an Atlas V rocket Friday from Cape Canaveral in Florida, United States, and placed a fourth infrared sensing satellite into orbit, as part of the US Air Force missile-detection system.



The liftoff occurred at 7.48pm from a platform of the complex 41 of the space center, and is the US Air Force’s fourth Space Based Infrared System (SBIRS) missile-detection satellite.



The three previous launches put into orbit a satellite weighing about 4,500 kilos in 2011, 2013 and January 2017.



This latest takeoff was achieved after the United Launch Alliance, a joint venture between Lockheed Martin and Boeing, suspended the launch on Thursday due to a ground issue associated with the booster liquid oxygen system, according to the company.



The rocket carried out the entire separation process and managed to leave the satellite in orbit in just a little over 40 minutes.



SBIRS is one of the highest priority space programs in the US and has been designed to meet the 21st century demands in four national security mission areas: missile warning, missile defense, technical intelligence and space combat awareness”, according to the United Launch Alliance.



The launch of the Atlas V, which has carried out 75 flights, will be the first one that the company conducts this year from the Florida complex, and the second in 2018 after a Delta IV rocket sent a classified intelligence spacecraft to orbit from California last Friday.



Besides, it will also be the 125th launch since the United Launch Alliance was founded in the year 2006.</s>CAPE CANAVERAL, Fla. - Atlas V launched another satellite for the United States Air Force Friday evening.

SBIRS GEO-4, the fourth satellite of its kind to go into high orbit around the earth, is designed to use infrared to spot heat coming from potential missiles launched on earth, giving the U.S. an early heads-up on strikes.

The launch was previously scheduled for Thursday, but officials delayed it until Friday.

Three other SBIRS satellites launched by the Atlas V went to the same orbit and all sit about 22,000 miles above the earth's surface in the geostationary orbit.

Officials said in orbit, the satellites match the speed of the earth's rotation, so they seem to hover over the same patch of land at all times, helping to provide information for the US missile defense systems and data about what kinds of launches are happening on the ground.

The SBIRS GEO-4 took off from Cape Canaveral Air Force Station in Florida at about 6:48 p.m.</s>A United Launch Alliance Atlas V rocket lifted off from Cape Canaveral Air Force Station's Launch Complex 41 at 7:48 p.m. with a ballistic missile detection satellite for the Air Force.

Se updates from the event below:
An Atlas V rocket successfully deployed the fourth SBIRS satellite for the United States Air Force. This launch completes the geosynchronous segment of SBIRS and provides a global missile detection system for the United States.