NASA Demonstrates Powered Flight On Mars
At 12:33 p.m. Mars time (3:34 a.m. EDT) on April 19 a small helicopter lifted off from the planet’s Jezero Crater in the first demonstration of powered flight beyond Earth.
The 4-lb. Ingenuity rotorcraft, designed and built at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, was airborne in the thin atmosphere of Mars for 39.1 secs., according to altimeter data relayed to ground controllers.
“We can now say that human beings have flown a rotorcraft on another planet,” project manager MiMi Aung told the JPL team on a NASA TV broadcast.
With its four blades spinning more than 2,400 rpm—five times faster than a small helicopter on Earth—Ingenuity flew 10 ft. above the ground, hovered for 30 sec., descended and then settled back on its four carbon composite landing legs, successfully completing the first of up to five flight tests planned over the next two weeks.
Ingenuity flew as a secondary payload on NASA’s Mars rover Perseverance, which landed in Jezero Crater on Feb. 18 for a two-year primary mission to look for signs of past microbial life and cache samples for a return trip to Earth. The rover’s science mission will follow the Ingenuity flight test program, which runs through May 4. Perseverance serves as Ingenuity’s communications relay.
The unprecedented technology demonstration sets the stage for an entirely new way to explore Mars—as well as other planetary bodies even if they, like Mars, have just a wisp of atmosphere.
At ground level the air density on Mars is less than 1% the density of Earth’s, so flying on Mars is equivalent to operating at around 100,000 ft. on Earth—about 2.5 times the maximum altitude achieved by any helicopter to date.
NASA’s design compensates for the thin air with two 4-ft. counter-rotating, composite wide chord rotor blades that spin five times faster than the typical 400-500 rpm of a small helicopter on Earth. The coaxial design incorporates collective and cyclic control on both rotors.
“A platform like Ingenuity will be, in my opinion, a powerful new tool for exploration. It gives you more range than the rovers and better resolution than the orbiters,” said Scott Hubbard, a retired Stanford University adjunct professor who led NASA’s first Mars program office and later served as the director of the agency’s Ames Research Center in Moffett Field, California.
“In all the evolution of rovers, from the little bitty Pathfinder to Curiosity and Perseverance, I can’t count how much time the science team has spent trying to figure out the next traverse, the next science place to go. Boy, if you had the ability to go out a kilometer or something, look around and take some high-resolution pictures that would really be beneficial,” Hubbard said in an interview with Aerospace DAILY.
Pathfinder and the prototype Sojourner rover landed in 1997, reopening NASA’s surface exploration of Mars after a 20-year hiatus. That mission was followed by the now-defunct Spirit and Opportunity rovers, the still-operational Curiosity rover and the newly arrived Perseverance.
“With something like Ingenuity, you can go and take a look at things that are so extreme you wouldn’t probably plan on sending a rover there,” Hubbard said. Those places include Valles Marineris—Mars’ extreme Grand Canyon, which stretches 2,500 mi. across the planet and reaches depths of 6 mi.
Aerial reconnaissance of Mars also promises to play a role in the future human exploration of Mars, Hubbard added. “You’re not going to get very far on foot—I don’t know if there will be a Mars dune buggy—but that scouting ability is really important.”
NASA had hoped to begin Ingenuity’s flight tests on April 11 but encountered a software timing issue on April 9 that prevented the helicopter from transitioning from preflight to flight mode for a high-speed rotor spin test.
“It’s a very subtle timing issue that did not surface during [preflight ground] tests,” Aung told Aerospace DAILY before the flight.
The helicopter team devised a simple workaround that added an extra checkpoint to a watchdog timer system that had triggered the April 9 abort. That solution precluded the need for a time-consuming rebuild, revalidation and reload of Ingenuity’s full flight software. However, tests show the software modification works just about 85% of the time, Aung noted.
Following the successful flight on April 19, Aung and her team will mull whether to pause the test program and complete the software re-validation and upload to better the odds that Ingenuity will be able to continue the flight sequence uninterrupted.
The other option is to continue to use the software patch, which though not fully reliable, poses no danger to the vehicle. “If for some reason it doesn’t go into flight mode, we’ll try again the next day,” Aung said before the April 19 test. “We’re focused on the first flight and then this will be a quick, but deep, conversation about the next step.”
After the flight, NASA Associate Administrator for Science Thomas Zurbuchen announced that the Martian airfield on which the flight took place would be named Wright Brothers Field. “Now, 117 years after the Wright brothers succeeded in making the first flight on our planet, NASA’s Ingenuity helicopter has succeeded in performing this amazing feat on another world,” Zurbuchen said in a press release. “While these two iconic moments in aviation history may be separated by time and 173 million mi. of space, they now will forever be linked.”