The SUV-sized Perseverance rover to launch on Mars this week has a companion: a splendid four-pound helicopter with four-foot-long rotor blades that weigh as light as feathers. It will attempt to make the first powered flight on another planet, a potential game changer for deep space exploration.
If all goes according to plan, dispatching the helicopter from the Perseverance womb will be an early first step for the Mars 2020 mission after the rover’s parachute, retro rocket, and celestial crane descend to the flat floor of the planet’s Jezero crater earlier from 2021. Intended only As a technology demonstration, the helicopter, called Ingenuity, will attempt up to five powered flights in the thin Martian air, which is less than 1 percent of the density of Earth’s atmosphere.
These trips will be fast, each lasting approximately 90 seconds from takeoff to landing, which is all the time available before Ingenuity’s batteries run out. To push enough air downward to create an upward lift, its blades have to rotate at around 2,800 revolutions per minute, 10 times faster than helicopters on Earth, so each flight will consume about 350 watts of power. Ingenuity’s solar-powered batteries will take a full Martian day (a little more than an Earth day) to recharge between flights. The spacecraft’s maximum altitude will be only 16 feet, but the conditions it will face will be comparable to those experienced at 100,000 feet on Earth, more than twice the height of any helicopter.
Planning for the Mars helicopter began more than six years ago in the autonomous systems division of NASA’s Jet Propulsion Laboratory (JPL), which studies next-generation capabilities for space exploration. The team, led by engineer MiMi Aung, was challenged to create a flying vehicle that would work on the Red Planet.
If successful, an aircraft could carry scientific instruments to places where rovers and landers cannot go, such as ice scarps exposed on the sides of cliffs or within steep crater walls. The plane could raise cameras to explore locations for future explorers and, someday, astronauts to explore. Doing so would provide much more detailed imaging than is available through current orbital imaging, which can resolve features on Mars of up to approximately three feet. “Imagine having centimeter level precision, [or about half-inch-precision], images of possible destinations and characterize them, “says Aung.
Future concepts include swarms of vessels flying together and working cooperatively or a larger flight vehicle that could travel independently from one location to another, allowing a new type of exploration from another world. JPL is studying possible Mars helicopters weighing up to 33 pounds that could carry a payload of up to approximately 3.3 pounds. NASA is also funding a much more ambitious helicopter-based mission called Dragonfly to explore the rich organic chemistry on Saturn’s largest moon Titan. The natural satellite has a thick atmosphere and lakes and seas of liquid methane underneath its thick hydrocarbon atmosphere, as well as a watery underground ocean, making it a tempting world in search of life beyond Earth.
“What has really changed in recent years is the drone revolution: how much development there has been in drones and autonomous flight technology,” says planetary scientist Elizabeth Turtle, Dragonfly principal investigator at the Applied Physics Laboratory at Johns Hopkins University. “When we were looking at mission architectures that made sense to propose exploring Titan, we realized that now we really had all this ability.”
First, however, it must be shown that powered flight on Mars is possible. And doing so is the sole objective of the $ 85 million Ingenio mission.
The helicopter is slightly larger than a softball, minus its four carbon fiber blades, which rotate on two counter-rotating rotors and sit on four legs, each 15 inches long. It carries tiny avionics and communications equipment, a navigation camera, a single solar panel, and rechargeable lithium-ion batteries, as well as heaters to keep electronics warm on cold Martian nights. There are no scientific instruments on board; just a high resolution color image generator.
The design of the helicopter required innovation in all areas of aerospace engineering: thermal, mechanical, structural, power, materials, etc. “We had to remove all limits,” says Aung. “We are used to having our own chassis … and our own computer for each subsystem. Integrating all that together, and then combining, also, the aerodynamic aspect, uniting the entire system in such a light weight … was the first challenge. That’s what also made it really fun and interesting. “
The mill will travel to Mars connected to the Perseverance rover and behind a shield to protect it from the debris that can be raised during the descent of the celestial crane to the planet’s surface. The launch is scheduled for 7: 50–9: 50 AM EDT on July 30 at Cape Canaveral Air Force Station in Florida. Perseverance is expected to land on Mars on February 18, 2021.
As the rover begins to transmit data that will allow scientists to evaluate Jezero Crater, the landing site of NASA’s fifth and most ambitious Mars rover, Aung and his team will search for a 33-by-33-foot flat site to become the experimental airfield. for Ingenuity test flights, which are scheduled to start in May.
The mill will not be the first spacecraft to fly through another planet’s atmosphere. That distinction goes to a pair of balloons that pierced the skies of Venus in 1985, collecting weather data as part of the Vega missions of the Soviet era. But Ingenuity will attempt the world’s first powered flight, a Wright Brothers moment for the 21st century.
After leaving the helicopter, Perseverance will retreat at least 100 yards away, far enough to avoid being hit in the event that Ingenuity hangs but still close enough for radio communications. Its maximum of five flights will take place within a span of 30 Martian days, after which the rover will resort to its primary mission: to assess the habitability of the Jezero crater and to cache samples of rocks and soils that may contain microfossils or other evidence of past microbial life
During the final test, Ingenuity could fly up to 150 feet away, perhaps reaching its modest maximum altitude before returning to its take-off point. “Because this is a pathfinder, we don’t have a hazard detection and avoidance system,” says Aung. “That would be essential for future helicopters, because just before landing, you would want a three-dimensional digital elevation map to be able to deflect and avoid any danger.”
The most important flight test on Mars will be the first, which will replicate those previously conducted within a 25-foot diameter vacuum chamber at JPL. “We take off, we plan, we do a modest side flight, we go back and land,” says Aung. “It is extremely important, because it confirms all our models, all the tests that we have done on Earth.”
After that trip, Ingenuity flights should be a bit bolder, with the helicopter traveling higher and then laterally farther before returning to land. “There is a saying in the aviation community that the only thing more exciting than taking off in your own plane is to land it again,” says Håvard Grip, the lead pilot for Ingenuity. “I think that is the case here.”
The mill is one of three technology demonstrations planned for the Mars 2020 mission. The second is an autonomous navigation system to avoid hazards that Perseverance will use during its descent to the 28-mile-wide Jezero Crater. And the third is an instrument called the Mars Oxygen In Situ Resource Utilization Experiment (MOXIE), which will attempt to convert carbon dioxide removed from the atmosphere into oxygen, a resource for possible future human missions to Mars.
