NASA’s Ingenuity Mars helicopter worked so well on its initial test flights that NASA has decided to extend its mission another 30 sols (Mars days).
But instead of simply testing the helicopter, says Lori Glaze, director of NASA’s Planetary Science Division, it will be seeing how it can be used to help explore the Martian landscape in tandem with the Perseverance rover.
“It’s going to transition from a technology demonstration to an operations demonstration,” she says.
“It’s a new phase,” says the helicopter’s project manager, MiMi Aung of NASA’s Jet Propulsion Laboratory, in California.
Initially, Aung says, the goal was simply to demonstrate that it was possible to fly on Mars, and then to investigate how flying Ingenuity on Mars differed from flying it in the lab – important information for the development of the next generation of Mars helicopters. In the process, she expected that the helicopter would be pushed close enough to its limits that its last flight of the month was likely to be a crash.
But it turned out that there were precious few differences between flying on Mars and the engineers’ expectations.
In its first three flights, the helicopter demonstrated that it could rise, hover, fly, track its elevation to within a centimetre, and land safely at precisely the designated position. “All in all, it’s really a great-performing vehicle,” says Bob Balaram, the helicopter’s chief engineer.
What that means is that the Perseverance rover team is suddenly gifted with a functional helicopter that might actually be able to carry out aerial reconnaissance.
To test that, the helicopter’s fourth flight last Saturday (AEDT) saw it airborne for 117 seconds, flying 133 metres out and back, and taking about 60 black-and-white and 5 colour images along the way.
These, Aung says, will be used to make 3D maps of the surrounding terrain—maps that can be used to find another safe landing zone for the fifth flight.
That flight will be a one-way trip to the new “airfield,” demonstrating that the helicopter can scout out its own landing zone on one flight, then go to it on the next, leaping across the Martian surface, rather than staying at a single base.
Meanwhile, says Jenifer Trosper, the rover’s deputy project manager, the Perseverance rover itself will go back to its main mission, to study Jezero Crater and collect samples for eventual return to Earth.
Previously, she says, scientists had thought that this was the point where Ingenuity would have to be abandoned, even if it hadn’t crashed.
That’s because the helicopter can only fly for 2 minutes per outing, before it has to land, lest its motor overheat, says Balaram. And because it’s solar powered, it has to recharge its batteries. It wasn’t expected to take long for the rover to outdistance it and lose contact.
But, says Trosper, it turns out that the rover won’t be driving very far in the next few weeks.
“We thought we would be driving away from the region we landed,” she says, “but the sample team is interested in getting the [first] samples from this region.”
That area, says Ken Farley, a project scientist at California Institute of Technology (Caltech), is a narrow strip about 1.6km long that appears to contain ancient mudstones.
These are formed from what was once silt at the bottom of the lake that once filled the crater, coming from a time when the lake would have been particularly habitable. They are also the type of sediment that is most likely to preserve signatures of ancient life, he says. “[So] we are planning to explore this area looking for interesting rocks.”
Will Ingenuity be able to help find the best sample sites? Time will tell.
Meanwhile, Farley says, “we appreciate the [helicopter’s] scouting ability and the ability to fly to territory the rover could not traverse. This is useful for future missions that could combine a rover with a helicopter.”
With flight number four logged, however, the helicopter team will have to slow down the pace of its operations.
For the past month, the rover’s main job has been to babysit the helicopter, taking pictures of it as it flies, and limiting its own activities to minimize the risk of electrical interference with the helicopter’s signals.
Now, the helicopter takes a backseat, and will only fly when it doesn’t distract from the rover’s main mission.
“We will fly every few weeks instead of every few sols,” Trosper says.
After 30 sols, the new phase of the helicopter’s mission will be re-evaluated, and possibly extended again.
“Right now it’s healthy,” Balaram says. “But it wasn’t designed for a long mission and its components haven’t been tested for how many cold Martian nights they can tolerate before something snaps.” But he says, “there are no consumables on this helicopter. The only consumable is our landing gear, which is good for up to 100 landings”.
All told, Glaze says, this is a “see how it goes” phase of the mission. “There is the potential to go beyond [30 days] but we’ll have to assess after 30 days.”
Not to mention that there is still the risk of a crash. “We are transferring to airfields that are not well characterised,” Aung says, “so there is higher possibility of errant landings.”