The work isn’t over for NASA’s Ingenuity Mars helicopter.
Engineers hope to fly the rotorcraft four more times in the next two weeks before calling it quits on the pioneering technology experiment, which accomplished the first powered flight of an aircraft on another planet Monday.
As officials celebrated the helicopter’s historic flight, teams were already looking forward to a series of more daring hops to take Ingenuity higher and farther away from its makeshift “airfield” on the Red Planet.
The helicopter’s one-month test flight campaign officially began April 3, then the Perseverance rover deployed Ingenuity onto the surface of Mars.
“We have a 30 day experiment window, so we have two weeks left,” said MiMi Aung, Ingenuity’s project manager at NASA’s Jet Propulsion Laboratory in California.
She said the helicopter will attempt “increasingly bolder flights” that could travel more than 2,000 feet (600 meters) from its takeoff location. “We do want to push it, and I believe we have enough time to squeeze the next four flights in the next two weeks left.”
“Ultimately, we expect the helicopter will meet its limit,” Aung said. “But that information is extremely important. This is a Pathfinder. This is about finding unknown unknowns that we can model, and we really want to know what the limits are, so we will be pushing them very deliberately.”
On its first flight Monday, the helicopter took off to an altitude of about 10 feet (3 meters) Monday, hovered and turned, then set down in the same location. Due to the vast distance to Mars — some 173 million miles (278 kilometers) from Earth — there’s no real-time control of the helicopter. Instead, Ingenuity uses an altimeter, navigation camera, and a sophisticated processor to help guide its motion.
“From everything we’ve seen thus far, it was a flawless flight,” said Håvard Grip, Ingenuity’s chief pilot at JPL. “It was a gentle takeoff. At altitude, it gets pushed around little bit by the winds, but it really just maintained station very well, and it stuck the landing right in the place it was supposed to go.”
Cameras on-board the Ingenuity helicopter took pictures throughout the automated test flight. Long-range observations from NASA’s Perseverance rover showed the rotorcraft’s historic flight from an observation post about 211 feet (64 meters) away.
The rover’s Mastcam-Z instrument, featuring two telephoto cameras capable of long-distance imaging, recorded video of the 39-second flight. The first video downlinked from the Perseverance rover was a wide-angle view recorded in 720p at 6.7 frames per second, according to Justin Maki, deputy principal investigator for the Mastcam-Z instrument at JPL.
Ingenuity beamed black-and-white images from an down-looking on-board camera back to ground teams Monday. Grip said the imagery indicated the helicopter kicked up less dust than expected, a good sign for future flights.
The data route between the helicopter and mission control passes through a base station on the Perseverance rover, then through an orbiter flying around Mars, which then transmits information back to engineers on Earth. Commands from mission control reach the helicopter the same way.
Still to come are the first views from a color camera on the helicopter, and a more zoomed-in view from Perseverance’s other Mastcam-Z camera that should show a portion of the rotorcraft’s flight.
“We are swimming in data right now,” Maki said.
Steve Jurczyk, NASA’s acting administrator, congratulated the helicopter team on an “amazing job.”
“This really is a Wright Brothers’ moment,” he said. “It’s the start of a whole new kind of planetary exploration, and we’ll build on Ingenuity’s success to see how we can deploy this capability on future Mars missions.”
NASA says it developed and flew the Ingenuity helicopter on an $85 million budget. The success adds a new dimension to the way NASA explores other worlds.
“We have this evolution of exploring planets in the solar system, first we do a flyby, then we’ll do an orbiter mission, then we’ll do a lander mission, we’ll land a rover, and now we’ve added another evolutionary capability … of flight on another planet,” Jurczyk said.
President Biden said the helicopter flight on Mars “proved once again that with relentless determination and the power of America’s best minds, anything is possible.”
Ingenuity’s fuselage is not much larger than a tissue box, and its twin counter-rotating carbon-composite rotor blades span about 4 feet (1.2 meters) tip-to-tip. The entire helicopter weighed about 4 pounds (1.8 kilograms) on Earth, or 1.5 pounds under weaker Martian gravity.
Members of the NASA Ingenuity helicopter team attach a thermal film to the exterior of the flight model of the rotorcraft. The image was taken on Feb. 1, 2019 inside the Space Simulator, a 25-foot-wide (7.62-meter-wide) vacuum chamber at NASA’s Jet Propulsion Laboratory in Pasadena, California. Credit: NASA/JPL-Caltech
Officials said one of the biggest challenges of the Mars helicopter’s six-year development was controlling the rotorcraft’s weight. Engineers had to fit the rotorcraft’s computer, batteries, rotor blades, and motors under the strict weight limit.
The rotors have to spin at near 2,500 rpm, much faster than helicopter blades on Earth, to create enough lift to power Ingenuity off the ground in the rarefied atmosphere of Mars, which is less than 1% the density of Earth’s at sea level. That’s roughly equivalent to the density of Earth’s atmosphere at 100,000 feet.
Ingenuity’s team took some extra time preparing for the first flight after a command sequence error cut short a spin-up test of the helicopter’s rotors. The time to troubleshoot the problem delayed Ingenuity’s first takeoff by about eight days, but officials are still optimistic to complete the helicopter’s five-flight test campaign by early May.
The second flight is scheduled as soon as Thursday, when Ingenuity will climb to an altitude of about 16 feet (5 meters), according to Aung. The helicopter will move laterally nearly 7 feet (2 meters), then come back to its original position for landing.
Flight No. 3 will extend the range of the helicopter by flying up to 160 feet, or 50 meters, from its “helipad” before returning for touchdown.
Grip, a guidance engineer serving as the helicopter’s chief pilot, said ground teams will command Ingenuity to travel downrange at around 4.5 mph (2 meters per second) on the third flight.
“In general terms, what we’re talking about here is going higher, going farther, going faster — stretching the capabilities of the helicopter in those ways,” Grip said.
Plans for the fourth and fifth flights haven’t been announced, but Aung said she hopes the helicopter can travel to distances between 600 and 700 meters, or nearly a half-mile, from its airfield — and go “as fast as we can go.”
According to Grip, the theoretical limit for Ingenuity’s altitude is constrained by the rotorcraft’s altimeter, which uses a laser range finder to measure the distance from the helicopter to the ground. That altitude limit is “probably around 10 meters (33 feet), or a little bit more, but not much more,” Grip said.
Teams also want to ensure the helicopter stays within range of its communications relay station on the Perseverance rover.
NASA named the helicopter’s takeoff and landing zone as “Wright Brothers Field.” The space agency also announced the International Civil Aviation Organization — the United Nations’ civil aviation agency — presented NASA and the Federal Aviation Administration with the official ICAO designator IGY, call-sign INGENUITY.
The location of the flight also received the ceremonial location designation JZRO for Jezero Crater, where the Perseverance rover landed Feb. 18, according to NASA.
Ingenuity’s demonstrations are scheduled to end in early May to allow the Perseverance rover to continue its primary mission. The $2.7 billion mission is designed to explore an ancient dried-up river delta a few miles from where the rover landed on Mars on Feb. 18.
Perseverance will gather rock samples for return to Earth on a future mission due to arrive on Mars in the late 2020s. Scientists will analyze the specimens — the first pristine samples ever returned from Mars — in search of signs of ancient life.
Ingenuity paves the way for aerial scouts that NASA could dispatch across the solar system. Future airborne drones could provide reconnaissance for rovers and astronauts exploring the surfaces of other worlds, and they could reach areas inaccessible to other vehicles, according to NASA officials.
NASA has selected a robotic mission named Dragonfly to explore Saturn’s largest moon Titan. But Titan has a much thicker atmosphere than Mars, which eases the difficulty of rotor-driven flight. The Dragonfly mission is scheduled for launch in 2027.
There are no more helicopters currently scheduled to fly to Mars. Thomas Zurbuchen, head of NASA’s science mission directorate, said one area where future Mars helicopters might assist scientists is in exploring the walls of craters, places inaccessible to rovers driving on the surface.
Bob Balaram, Ingenuity’s chief engineer, said Monday that the Ingenuity design could be scaled up to masses between 25 and 50 kilograms — or 55 to 110 pounds — to accommodate scientific instruments. Ingenuity’s only payloads are black-and-white and color cameras.
NASA’s next Mars lander is scheduled for launch in 2026. It will land in the Jezero Crater region to retrieve the rock samples collected by the Perseverance rover, then launch the specimens on a journey back to Earth.