Ingenuity (helicopter)

Ingenuity is a small robotic solar helicopter and lightest spacecraft operating on Mars as part of NASA's Mars 2020 mission. On April 19, 2021, it successfully completed the first powered controlled flight by an aircraft on a planet besides Earth, taking off vertically, hovering and landing. With five successful flights as of May 7, 2021, the battery-powered coaxial drone rotorcraft is serving as a technology demonstrator for the potential use of flying probes on future missions to Mars and other worlds, and will have the potential to scout locations of interest and support the future planning of driving routes for Mars rovers. Dave Lavery is the program executive, MiMi Aung is the project manager, Håvard Fjær Grip is the Chief Pilot, and Bob Balaram is Chief Engineer. Other contributors include AeroVironment, Inc., the NASA Ames Research Center, and the NASA Langley Research Center.
"Ingenuity" was intended to fly up to five times during its 30-day test campaign scheduled early in the rover's mission. Primarily technology demonstrations, each flight was planned to fly at altitudes ranging from above the ground for up to 90 seconds each. "Ingenuity", which can travel up to downrange and then back to the starting area, uses autonomous control during its short flights, which are telerobotically planned and scripted by operators at Jet Propulsion Laboratory (JPL). It communicates directly with the "Perseverance" rover after each landing. The expected lateral range was exceeded in the third flight, the flight duration was exceeded in the fourth flight. This was later designated as the first phase of its mission, to demonstrate the possibility of flight. The second phase was later designated (after successful completion of that mission) as a demonstration of the operational possibilities for Mars exploration and conquest. 
"Ingenuity" travelled to Mars attached to the underside of the "Perseverance" rover, arriving at the Octavia E. Butler Landing site in Jezero crater on February 18, 2021. It deployed on April 3, 2021, and after unloading the drone "Perseverance" drove approximately away to allow it a safe "buffer zone" in which it made its first flight. On 19 April 2021 at 07:15 UTC, "Ingenuity" had its first takeoff, with livestreaming 3 hours later at 10:15 UTC confirming the flight. "Ingenuity" rose and hovered there for about 30 seconds before returning to the surface of Mars (with a total flight time of 39.1 seconds).
"Ingenuity" carries a piece of fabric from the wing of the 1903 "Wright Flyer", the Wright Brothers' airplane, which was humanity's first controlled powered heavier-than-air flight on Earth. The initial take-off and landing area for "Ingenuity" is named Wright Brothers Field as a tribute. Before "Ingenuity" achieved the first heavier-than-air powered flight on another planet, the first flight on a planet beyond Earth was an unpowered balloon flight on Venus, by the Soviet Vega 1 spacecraft in 1985. 
With the success of its fourth flight on April 30, 2021, "Ingenuity" achieved its original objectives. NASA then planned future flights not as pure technical demonstrations but as operations demonstrations. With these new objectives, the "Ingenuity" team hopes to demonstrate how future missions can work together in further collaborations. During its April 30, 2021 flight, "Ingenuity" also became the first interplanetary spacecraft whose sound was recorded by another interplanetary spacecraft, the "Perseverance" rover. On its May 7, 2021 flight, "Ingenuity" became the first interplanetary spacecraft which landed at a different place than the launch site.
Design.
Because the atmosphere of Mars is only about as dense as that of Earth at surface level, it is much harder for an aircraft to generate lift, a difficulty only partially offset by Mars' lower gravity (about a third of Earth's). Flying close to Mars' surface has been described as equivalent to flying at more than above Earth, an altitude that has never been reached by existing helicopters. Made mostly of carbon dioxide, Mars' atmosphere requires blade rotation speeds of 2,400 rpm for "Ingenuity" to stay aloft, about five times what is needed on Earth.
"Ingenuity" is designed to be a technology demonstrator by JPL to assess whether this technology can fly safely, and provide better mapping and guidance that would give future mission controllers more information to help with travel routes planning and hazard avoidance, as well as identifying points of interest for the rover. The helicopter is designed to provide overhead images with approximately ten times the resolution of orbital images, and will provide images of features that may be occluded from the cameras of the "Perseverance" rover. It is expected that such scouting may enable future rovers to safely drive up to three times as far per sol.
The helicopter uses contra-rotating coaxial rotors about in diameter. Its payload is a high resolution downward-looking camera for navigation, landing, and science surveying 
of the terrain, and a communication system to relay data to the "Perseverance" rover. Although it is an aircraft, it was constructed to spacecraft specifications in order to endure the acceleration and vibrations during launch. It also includes radiation-resistant systems capable of operating in the frigid environment of Mars. The inconsistent Mars magnetic field precludes the use of a compass for navigation, so it uses a solar tracker camera integrated to JPL's visual inertial navigation system. Some additional inputs include gyros, visual odometry, tilt sensors, altimeter, and hazard detectors. It was designed to use solar panels to recharge its batteries, which are six Sony Li-ion cells with of battery energy capacity (nameplate capacity of 2 Ah).
The flight duration is not constrained by the available energy but by the waste heat that heats up the motors during flight at a rate of 1 K/s.
The helicopter uses a Qualcomm Snapdragon 801 processor with a Linux operating system. Among other functions, this processor controls the visual navigation algorithm via a velocity estimate derived from features tracked with a black-and-white downward-facing navigation camera containing an Omnivision OV7251 global-shutter sensor or horizon-facing terrain camera. 
The Qualcomm processor is connected to two flight-control microcontroller units (MCUs) to perform the necessary flight-control functions. It also carries a cellphone grade Bosch BMI-160 IMU, a Murata inclination sensor SCA100T-D02 and a Garmin LIDAR Lite v3 laser altimeter. Communications with the rover are through a radio link using low-power Zigbee communication protocols, implemented via 900 MHz SiFlex 02 chipsets mounted in both the rover and helicopter. The communication system is designed to relay data at 250 kbit/s over distances of up to .
Development.
NASA's JPL and AeroVironment published the conceptual design in 2014 for a scout helicopter to accompany a rover. By mid 2016, US$15 million was being requested to keep development of the helicopter on track. By December 2017, engineering models of the vehicle had been tested in a simulated Martian atmosphere and models were undergoing testing in the Arctic, but its inclusion in the mission had not yet been approved nor funded. The United States federal budget, announced in March 2018, provided US$23 million for the helicopter for one year and it was announced on May 11, 2018 that the helicopter could be developed and tested in time to be included in the Mars 2020 mission. The helicopter underwent extensive flight-dynamics and environment testing, and was then mounted on the underside of the "Perseverance" rover in August 2019. Its mass is just under and JPL has specified that it is planned to have a design life of five flights on Mars. NASA has invested about US$80 million to build "Ingenuity" and about US$5 million to operate the helicopter.
In April 2020, the vehicle was named "Ingenuity" by Vaneeza Rupani, a girl in the 11th grade at Tuscaloosa County High School in Northport, Alabama, who submitted an essay into NASA's "Name the Rover" contest. Known in planning stages as the Mars Helicopter Scout, or simply the Mars Helicopter, the nickname Ginny later entered use in parallel to the parent rover "Perseverance" being affectionately referred to as "Percy".
Preliminary tests on Earth.
In 2019, preliminary designs of "Ingenuity" were tested on Earth in simulated Mars atmospheric and gravity conditions. For flight testing, a large vacuum chamber was used to simulate the very low pressure of the atmosphere of Mars – filled with carbon dioxide to approximately 0.60% (about ) of standard atmospheric pressure at sea level on Earth – which is roughly equivalent to a helicopter flying at altitude in the atmosphere of Earth. In order to simulate the much reduced gravity field of Mars (38% of Earth's), 62% of Earth's gravity was offset by a line pulling upwards during flight tests. A "wind-wall" consisting of almost 900 computer fans was used to provide wind in the chamber.
Future Mars rover design iteration.
The "Ingenuity" technology demonstrator could form the foundation on which more capable aircraft might be developed for aerial exploration of Mars and other planetary targets with an atmosphere. The next generation of rotorcraft could be in the range between with science payloads between . These potential aircraft could have direct communication to an orbiter and may or may not continue to work with a landed asset. Future helicopters could be used to explore special regions with exposed water ice or brines, where Earth microbial life could potentially survive. Mars helicopters may also be considered for fast retrieval of small sample caches back to a Mars ascent vehicle for return to Earth such as the one to be launched in 2026.
Mission profile.
After deployment, the rover drove approximately away from the drone to allow it a safe "danger zone" in which it flew in April 2021. The "Ingenuity" helicopter is expected to fly up to five times during its 30-day test campaign starting in April 2021, early in the rover's mission.
Each flight is planned to be at altitudes ranging from above the ground. In a NASA press conference on April 9, 2021, Operations Lead Tim Canham and Aung said that the first flight is planned to be a stationary hover at an altitude of , lasting about 40 seconds and including taking a picture of the rover, with subsequent flights being increasingly ambitious. Aung also explained that the flights would get more ambitious as experience is gained and the allotted time for operating the helicopter dwindles, and that the mission may end before the 30-day period is up, in the likely event that the helicopter crashes. In up to 90 seconds per flight, it could travel as far as downrange and then back to the starting area.
The helicopter uses autonomous control during its short flights, although flights are be telerobotically planned and scripted by operators at Jet Propulsion Laboratory (JPL). It communicates with the "Perseverance" rover directly after each landing.
After the successful first three flights, the objective was changed from technology demonstration to operational demonstration. The target is shifted towards supporting the rover’s science mission by mapping and scouting the terrain. On 30 April, 2021, the fourth flight resulted in "Ingenuity" successfully capturing numerous color photos and also exploring the surface of the terrain it covered with a black-and-white navigation camera.
 On May 7, Ingenuity successfully flew to a new landing site.
Operational history.
"Ingenuity" was deployed on April 3, 2021, after landing with the rover "Perseverance" in the crater Jezero at Octavia E. Butler Landing on February 18, 2021, and removal of the debris shield on March 21, 2021. The same day, "Ingenuity" took a photo of the surface of Mars which was transmitted back to Earth.
"Ingenuity" rotor blades were successfully unlocked on April 8, 2021 (mission sol 48) and it performed a low-speed rotor spin test. spinning at 50 rpm. A high-speed spin test was attempted on April 9, but failed due to the expiration of a watchdog timer, a measure to protect the helicopter from incorrect operation in unforeseen conditions. On April 12, a software update with a patch to correct the problem was announced. Since with an adapted command sequence there is an 85 % chance that it will work correctly, the update was not used. On April 17, 2021, "Ingenuity" successfully passed the full-speed spin test. The test involved spinning its rotor blades, while still on the surface, up to full speed at around 2400 rpm for the first time on Mars.
On April 19, 2021 at 7:34 UTC, the helicopter successfully performed the first powered flight on Mars, lasting 39.1 seconds. It rose vertically about , hovered, rotated in place 96 degrees in a planned maneuver, and landed. Data confirming the success of the test flight with the first photographs from "Ingenuity" mid-flight were later received at 11:30 UTC.
On April 22, 9:33 UTC, "Ingenuity" successfully performed its second flight, lasting 51.9 seconds. It rose vertically to about 5 meters (16 ft) and hovered briefly at that altitude. It then performed a 5 degree tilt, allowing the rotors to accelerate it 2 meters sideways, came to a stop, hovered in place, and made turns to point its camera in different directions. "Ingenuity" then headed back to the center of the airfield to land. Messages of this flight started coming in at 13:20 UTC. 
"Ingenuity" successfully performed its third flight on April 25, 2021, 11:31 UTC, lasting about 80 seconds. Similar to the last flight, "Ingenuity" rose about 5 meters (16 ft) and hovered briefly at that altitude. It then flew downrange 50 meters while maintaining its altitude, reaching a top speed of two meters per second. The downward-facing black and white camera helped "Ingenuity" keep track of its position above the ground. The helicopter flew back to the location above its takeoff spot and landed, completing a round-trip of about . Data from the flight was received at 14:16 UTC."Ingenuity"'s 4th flight was attempted on April 29, but failed due to the helicopter failing to transition to flight mode. It was re-attempted on April 30, 2021, 14:49 UTC, and succeeded, lasting 117 seconds. Just like the previous 2 flights, the helicopter rose to an altitude of 5 meters (16 ft), marking the start of the 4th flight. It then flew south about and back for a round trip of . Data from the flight was received soon after. A record number of images were captured and saved to the database, about 60 total during the last before the helicopter returned to its landing site. On May 7 NASA confirmed that "Perseverance" managed to record both audio and video from the fourth flight.
"Ingenuity"'s fifth flight succeeded on May 7, 2021, 19:26 UTC, lasting 108 seconds. "Ingenuity" went 5 meters (16 ft) high, just like the last three flights, and travelled to a landing site to the south. After arrival, the helicopter flew to an altitude of high, captured a few high-res color images of its landing site, and landed at the new site.
Tributes to the Wright brothers.
NASA and JPL officials described the first "Ingenuity" flight as their "Wright Brothers moment", by analogy to the first successful airplane flight on Earth. A small piece of the wing cloth from the Wright brothers' 1903 "Wright Flyer" is attached to a cable underneath "Ingenuity"s solar panel. In 1969, Apollo 11's Neil Armstrong carried a similar "Wright Flyer" artifact to the Moon in the Lunar Module "Eagle". 
NASA named "Ingenuity" first take-off and landing airstrip Wright Brothers Field, which the UN agency ICAO gave an airport code of JZRO for Jezero Crater, and the drone itself a type designator of IGY, call-sign INGENUITY.