Ingenuity (helicopter)
Ingenuity, nicknamed Ginny, is an autonomous NASA helicopter that operated on Mars from 2021 to 2024 as part of the Mars 2020 mission. Ingenuity made its first flight on 19 April 2021, demonstrating that flight is possible in the extremely thin atmosphere of Mars, and became the first aircraft to conduct a powered and controlled extraterrestrial flight. It was designed by NASA's Jet Propulsion Laboratory in collaboration with AeroVironment, NASA's Ames Research Center and Langley Research Center with components supplied by Lockheed Martin Space, Qualcomm, and SolAero.
Ingenuity was delivered to Mars on 18 February 2021, attached to the underside of the Perseverance rover, which landed at the Octavia E. Butler Landing site near the western rim of the Jezero crater. Because radio signals take several minutes to travel between Earth and Mars, it could not be manually controlled in real time, and instead autonomously flew flight plans sent to it by JPL.
Originally intended to make only five flights, Ingenuity completed 72 flights in nearly three years. The five originally planned flights were part of a 30-sol technology demonstration intended to prove its airworthiness with flights of up to 90 seconds at altitudes ranging from. Following this demonstration, JPL designed a series of operational flights to explore how aerial scouts could help explore Mars and other worlds. In this operational role, Ingenuity scouted areas of interest for the Perseverance rover, improved navigational techniques, and explored the limits of its flight envelope. Ingenuity's performance and resilience in the harsh Martian environment greatly exceeded expectations, allowing it to perform far more flights than were initially planned. On 18 January 2024, the rotor blades were broken during landing on flight 72, permanently grounding the helicopter. NASA announced the end of the mission one week later. Engineers concluded that Ingenuity's navigation system was not effective over the featureless terrain on the final flight, resulting in a crash landing. By the end of its mission, Ingenuity had flown for a total of two hours, eight minutes and 48 seconds over days, covering more than.
Development
Concept
The development of the project that would eventually become Ingenuity started in 2012 when JPL director Charles Elachi visited the lab's Autonomous Systems Division, which had done relevant concept work. By January 2015, NASA agreed to fund the development of a full-size model, which came to be known as the "risk reduction" vehicle.NASA's JPL and AeroVironment published the conceptual design in 2014 for a scout helicopter to accompany a rover. By mid-2016, $15 million was being requested to continue development of the helicopter.
By December 2017, engineering models of the vehicle had been tested in a simulated Martian atmosphere. Models were undergoing testing in the Arctic, but its inclusion in the mission had not yet been approved or funded.
Mission integration
When the Mars 2020 program was approved in July 2014, a helicopter flight demonstration was neither included nor budgeted.The United States federal budget, announced in March 2018, provided $23 million for the helicopter for one year, and it was announced on 11 May 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 mounted on the underside of the Perseverance rover in August 2019. NASA spent about $80 million to build Ingenuity and about $5 million to operate the helicopter.
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 about 0.60% 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, 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.
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. Its full-scale engineering model for testing on Earth was named Earth Copter and, unofficially, Terry.
Ingenuity was designed to be a technology demonstrator by JPL to assess whether such a vehicle could fly safely. Before it was built, launched and landed, scientists and managers expressed hope that helicopters could provide better mapping and guidance that would give future mission controllers more information to help with travel routes, planning, and hazard avoidance. Based on the performance of previous rovers through Curiosity, it was assumed that such aerial scouting might enable future rovers to safely drive up to three times as far per sol. However, the new AutoNav capability of Perseverance significantly reduced this advantage, allowing the rover to cover more than 100 meters per sol.
Development team
The Ingenuity team was comparatively small, with never more than 65 full-time-equivalent employees from JPL. Program workers from AeroVironment, NASA AMES and Langley research centers brought the total to 150. Key personnel include:- MiMi Aung – Ingenuity Mars Helicopter Project Manager at NASA's Jet Propulsion Laboratory,
- Bob Balaram – Chief Engineer
- Timothy Canham – Flight Software Lead and Operations Lead
- Håvard Fjær Grip – GNC Lead and Chief Pilot
- Matt Keennon – AeroVironment Technical Lead
- Loay Elbasyouni – Lead Electrical and Power Electronics Engineer.
- Ben Pipenberg – AeroVironment Design Lead
- Chris Bang - AeroVironment Mars Helicopter Program Manager
- Josh Ravich – Mechanical Engineering Lead
- Teddy Tzanetos – Operations Lead
- Nacer Chahat – Antenna Engineer and Telecom System Engineering
Opposition
The idea to include a helicopter in the Mars 2020 mission was opposed by several NASA leaders, scientists and JPL employees. Up until the end of the 2010s, they argued against integrating a helicopter into the mission. For three years, the future Ingenuity was developed outside the Mars 2020 project and its budget. Although NASA management accepted assurances in the spring of 2018 that the addition of a helicopter would not harm the goals of the expedition, Mars 2020 chief scientist Kenneth Farley stated; "I have personally been opposed to it because we are working very hard for efficiencies and spending 30 days working on a technology demonstration does not further those goals directly from the science point of view". Farley was convinced that the helicopter was a distraction from the priority scientific tasks, unacceptable even for a short time.The skepticism on the part of NASA leadership was not unfounded. Scientists, engineers and managers proceeded from a pragmatic comparison of the benefits of additional aerial reconnaissance with the costs that inevitably fall on the schedule for the rover to complete all the tasks assigned to it. During a live stream from NASA, MiMi Aung, the Ingenuity Project Manager, and Jennifer Trosper discussed the value of Ingenuity. Trosper argued that the Perseverance rover would outpace the helicopter due to its auto-navigation capability, thus negating one of central arguments for the value to the mission of the helicopter.
At the end of the test window, NASA extended support for Ingenuity for another 30 sols, limiting the frequency of departures to one flight every few weeks.
On 14 June 2021, the Director of the Mars Exploration program, E. Janson, and the Principal Mars Explorer, M. Meyer, directly addressed all the staff of the Mars 2020 project. During this address they cautioned the staff to keep their Ingenuity enthusiasm in check, and concentrate on collecting samples. On the same date, in their report to the Planetary Advisory Committee, the helicopter was mentioned only in the past tense, e.g. "...placed Ingenuity and completed the technology demonstration phase...".
Despite this early pessimism, Ingenuity proved to be more than capable of keeping up with Perseverance, actually staying ahead of the rover for the majority of the traverse up the Jezero delta.
While it was able to keep up with Perseverance, in the spring of 2022 the helicopter did begin to fall behind the rover starting at the beginning of Sol 400. Insufficient solar energy during the Martian winter was the main driver of poor operational performance in the latter half of 2022.
Design
Mechanical design
Ingenuity consists of a rectangular fuselage measuring suspended below a pair of coaxial contra-rotating rotors measuring in diameter. This assembly is supported by four landing legs of each. It also carries a solar array mounted above the rotors to recharge its batteries. The entire vehicle is tall.File:Ingenuity coaxial rotor assembly.png|thumb|left|upright=0.8|Ingenuity upper swashplate assembly
A – Rotor blade; B – Pitch link; C – Servo; D – Swashplate
The lower gravity of Mars only partially offsets the thinness of the 95% carbon dioxide atmosphere of Mars, making it much harder for an aircraft to generate adequate lift. The planet's atmospheric density is about that of Earth's at sea level, or about the same as at, an altitude never reached by existing helicopters. This density reduces even more in Martian winters. To keep Ingenuity aloft, its specially shaped blades of enlarged size must rotate between, or about 10 times faster than what is needed on Earth. Each of the helicopter's contra-rotating coaxial rotors is controlled by a separate swashplate that can affect both collective and cyclic pitch. Ingenuity was also constructed to spacecraft specifications to withstand the acceleration and vibrations during launch and Mars landing without damage.