NASA’s Ingenuity helicopter is currently sitting on the surface of Mars waiting for its first test flight. Ingenuity, which is about the size of a tissue box, will pave the way for future aerial exploration of the planet.
The Mars helicopter’s first test flight is scheduled for no earlier than April 14. For the first trial, the helicopter will go straight up, hover for about 30 seconds, then come straight back down. Ingenuity will be tested a total of five times in about 30 days, with each successive test building on the previous ones and adding more difficult maneuvers.
Although this is just a technology demonstration, other helicopters could be helpful for Mars exploration down the road. The agile aircraft can cover more area more quickly than a rover, explains Amiee Quon, mechanical integration engineer at the NASA Jet Propulsion Laboratory. Helicopters can also explore hard-to-reach areas like cliff faces. One day, Quon says, they could even perform some science tasks.
Ingenuity looks very different from helicopters on Earth. It’s small — small enough that it hitched a ride to Mars on the belly of the Perseverance rover — and has four legs, two blades and a solar panel. The blades are stacked on top of one another.
The martian helicopter operates differently from helicopters on Earth due to the difference in atmospheric densities between the two planets. Quon explains that Mars’s atmosphere is just one percent of the density of Earth’s atmosphere at sea level.
On Earth, typical helicopters big enough to carry people often have two rotors, one on top of the helicopter and another on its tail, explains Vincent Passerini, flight instructor at Smoketown Helicopters in Lancaster County.
The blades on the top rotor provide lift to get the helicopter into the air, while the blades on the tail help stabilize the helicopter, Passerini says. Together the blades control the aircraft’s horizontal motion, as well.
In contrast, the Mars Helicopter is considered a coaxial contra-rotating helicopter. It has two blades that spin in opposite directions around the same axis, Quon explains.
Additionally, Ingenuity is much smaller and lighter than the people-transporting helicopters on Earth, and its rotors spin much faster than those on Earth helicopters. Passerini says the blades on the helicopters at Smoketown Helicopters spin at about 500 revolutions per minute. To get Ingenuity in the air with Mars’s lighter atmosphere, its rotors spin at up to 2,400 rpm, says Quon.
Lots of calculations to redesign and miniaturize helicopters went into building a helicopter capable of operating on another planet. Developing a helicopter to fly on Mars also involved testing the technology in “Mars on Earth,” Quon explains. JPL has a space simulator that can mimic the conditions on Mars and is used to test spacecraft here before they’re launched.
“We had a very experienced helicopter pilot directly controlling the helicopter, and we discovered that A, we do have lift, and we can fly; and B, because of that thin atmosphere, though, things happen really quickly and humans’ reaction time [and] reflexes are not quite enough to deal with it,” Quon says.
Because of that, and because directly controlling the Mars helicopter from very far away on Earth isn’t feasible due to the delay in communication from here to there, Ingenuity operates autonomously. It needs to be able to run its heaters overnight so it doesn’t freeze, charge itself using its solar panel, and follow flight instructions that NASA conveys to it.
With the series of tests that Ingenuity will go through over the next month or so, Quon says “NASA is hoping to learn that we can fly the helicopter in the very thin atmosphere at Mars…We also want to prove that we can fly this autonomously.”
“By proving that we can fly autonomously and that we actually do have the lift, we can build more helicopters, potentially larger helicopters that can carry more payloads,” says Quon.
Ingenuity’s first test flight was originally scheduled for Sunday, April 11, but it was postponed due to an issue during a high-speed spin test. The first flight test will now take place no earlier than April 14. A statement on NASA’s website says, “The helicopter is safe and healthy.”