Blade Strike on Landing Ends Mars Helicopter’s Epic Journey

The Ingenuity Mars Helicopter made its 72nd and ultimate flight on 18 January. “Whereas the helicopter stays upright and in communication with floor controllers,” NASA’s Jet Propulsion Lab mentioned
in a press release this afternoon, “imagery of its Jan. 18 flight despatched to Earth this week signifies a number of of its rotor blades sustained harm throughout touchdown, and it’s now not able to flight.” That’s what you’re seeing in the picture above: the shadow of a damaged tip of one of many helicopter’s 4 two-foot lengthy carbon fiber rotor blades. NASA is assuming that a minimum of one blade struck the Martian floor throughout a “tough touchdown,” and this isn’t the type of harm that can permit the helicopter to get again into the air. Ingenuity’s mission is over.

The Perseverance rover took this image of Ingenuity on on Aug. 2, 2023, simply earlier than flight 54.NASA/JPL-Caltech/ASU/MSSS

NASA held a press convention earlier this night to present as a lot info as they will about precisely what occurred to Ingenuity, and what comes subsequent. First, right here’s a abstract
from the press release:

Ingenuity’s group deliberate for the helicopter to make a brief vertical flight on Jan. 18 to find out its location after executing an emergency touchdown on its earlier flight. Knowledge reveals that, as deliberate, the helicopter achieved a most altitude of 40 toes (12 meters) and hovered for 4.5 seconds earlier than beginning its descent at a velocity of three.3 toes per second (1 meter per second).

Nonetheless, about 3 toes (1 meter) above the floor, Ingenuity misplaced contact with the rover, which serves as a communications relay for the rotorcraft. The next day, communications had been reestablished and extra details about the flight was relayed to floor controllers at NASA JPL. Imagery revealing harm to the rotor blade arrived a number of days later. The reason for the communications dropout and the helicopter’s orientation at time of landing are nonetheless being investigated.

Whereas NASA doesn’t know for certain what occurred, they do have some concepts based mostly on the reason for the emergency touchdown in the course of the earlier flight, Flight 71. “[This location] is among the hardest terrain we’ve ever needed to navigate over,” mentioned
Teddy Tzanetos, Ingenuity Project Manager at NASA JPL, in the course of the NASA press convention. “It’s very featureless—bland, sandy terrain. And that’s why we consider that in Flight 71, we had an emergency touchdown. She was flying over the floor and was realizing that there weren’t too many rocks to have a look at or options to navigate from, and that’s why Ingenuity referred to as an emergency touchdown on her personal.”

Ingenuity uses a downward-pointing VGA camera running at 30hz for monocular feature tracking, and compares the obvious movement of distinct options between frames to find out its movement over the bottom. This optical circulate approach is used for drones (and different robots) on Earth too, and it’s very dependable, so long as you’ve sufficient options to trace. The place it begins to go unsuitable is when your digicam is issues which might be featureless, which is why client drones will typically warn you about surprising conduct when flying over water, and why robotics labs typically have weird carpets and wallpaper: the extra options, the higher. On Mars, Ingenuity has been reliably navigating by on the lookout for distinctive options like rocks, however flying over a featureless expanse of sand brought on severe issues, as Ingenuity’s Chief Pilot Emeritus Håvard Grip defined to us throughout at present’s press convention:

The way in which a system like this works is by wanting on the consensus of [the features] it sees, after which throwing out the issues that don’t actually agree with the consensus. The hazard is whenever you run out of options, whenever you don’t have very many options to navigate on, and also you’re not likely in a position to set up what that consensus is and you find yourself monitoring the unsuitable sorts of options, and that’s when issues can get off observe.

This view from Ingenuity’s navigation digicam throughout flight 70 (on December 22) reveals areas of practically featureless terrain that may trigger issues throughout flights 71 and 72.NASA/JPL-Caltech

After the Flight 71 emergency touchdown, the group determined to attempt a “pop-up” flight subsequent: it was purported to be about 30 seconds within the air, simply straight as much as 12 meters after which straight down as a check-out of the helicopter’s methods. As Ingenuity was descending, simply earlier than touchdown, there was a lack of communications with the helicopter. “Now we have motive to consider that it was going through the identical featureless sandy terrain challenges [as in the previous flight],” mentioned Tzanetos. “And due to the navigation challenges, we had a rotor strike with the floor that may have resulted in an influence brownout which brought on the communications loss.” Grip describes what he thinks occurred in additional element:

A few of that is hypothesis due to the sparse telemetry that we’ve got, however what we see within the telemetry is that coming down in the direction of the final a part of the flight, on the sand, once we’re closing in on the bottom, the helicopter comparatively shortly begins to assume that it’s shifting horizontally away from the touchdown goal. It’s possible that it made an aggressive maneuver to attempt to appropriate that proper upon touchdown. And that may have accounted for a sideways movement and tilt of the helicopter that would have led to both placing the blade to the bottom after which dropping energy, or making a maneuver that was aggressive sufficient to lose energy earlier than touching down and placing the blade, we don’t know these particulars but. We could by no means know. However we’re attempting as exhausting as we will with the info that we’ve got to determine these particulars.

When the Ingenuity group tried reestablishing contact with the helicopter the subsequent
sol, “she was proper there the place we anticipated her to be,” Tzanetos mentioned. “Photo voltaic panel currents had been wanting good, which indicated that she was upright.” The truth is, all the pieces was “inexperienced throughout the board.” That’s, till the group began wanting by means of the photographs from Ingenuity’s navigation digicam, and noticed the shadow of the broken decrease blade. Even when that’s the one harm to Ingenuity, the entire rotor system is now each unbalanced and producing considerably much less carry, and additional flights might be unattainable.

A closeup of the shadow of the broken blade tip.NASA/JPL-Caltech

There’s all the time that piece behind your head that’s preparing each downlink—at present might be the final day, at present might be the final day. So there was an preliminary second, clearly, of disappointment, seeing that picture come down and pop on display screen, which provides us certainty of what occurred. However that’s in a short time changed with happiness and pleasure and a sense of celebration for what we’ve pulled off. Um, it’s actually outstanding the journey that she’s been on and value celebrating each single a type of sols. Round 9pm tonight Pacific time will mark 1000
sols that Ingenuity has been on the floor since her deployment from the Perseverance rover. So she picked a really becoming time to come back to the top of her mission. —Teddy Tzanetos

The Ingenuity group is guessing that there’s harm to greater than one of many helicopter’s blades; the blades spin quick sufficient that if one hit the floor, others possible did too. The plan is to try to slowly spin the blades to convey others into view to try to gather extra info. It sounds unlikely that NASA will divert the Perseverance rover to present Ingenuity a better look; whereas persevering with on its honest mission the rover will come between 200 and 300 meters of Ingenuity and can attempt to take some photos, however that’s possible too far-off for a very good high quality picture.

Perseverance watches Ingenuity take off on flight 47 on March 14, 2023.NASA/JPL-Caltech/ASU/MSSS

As a tech demo, Ingenuity’s complete motive for existence was to push the boundaries of what’s attainable. And as Grip explains, even in its final flight, the little helicopter was doing precisely that, going above and past and attempting newer and riskier issues till it received so far as it presumably might:

General, the way in which that Ingenuity has navigated utilizing options of terrain has been extremely profitable. We didn’t design this technique to deal with this sort of terrain, however nonetheless it’s kind of been invincible till this second the place we flew on this utterly bland terrain the place you simply don’t have anything to actually maintain on to. So there are some classes in that for us: we now know that that exact type of terrain generally is a lure for a system like this. Backing up when encountering this featureless terrain is a performance {that a} future helicopter might be outfitted with. After which there are answers like having a better decision digicam, which might have possible helped mitigate this example. However it’s all a part of this tech demo, the place we outfitted this helicopter to do at most 5 flights in a pre-scouted space and it’s gone on to take action far more than that. And we simply labored all of it the way in which as much as the road, after which simply tipped it proper over the road to the place it couldn’t deal with it anymore.

Arguably, Ingenuity’s most essential contribution has been exhibiting that it’s not simply attainable,
but practical and valuable to have rotorcraft on Mars. “I don’t assume we’d be speaking about sample recovery helicopters if Ingenuity didn’t fly, interval, and if it hadn’t survived for so long as it has,” Teddy Tzanetos told us after Ingenuity’s 50th flight. And it’s not simply the pattern return mission: JPL can be creating a much larger Mars Science Helicopter, which can owe its existence to Ingenuity’s success.

Practically three years on Mars. 128 minutes and 11 miles of flight within the Martian skies. “I stay up for the day that one in every of our astronauts brings house Ingenuity and we will all go to it within the Smithsonian,” mentioned
Director of JPL Laurie Leshin on the finish of at present’s press convention.

I’ll be first in line.

We’ve written extensively about Ingenuity, together with in-depth interviews with each helicopter and rover group members, and so they’re nicely price re-reading at present. Thanks, Ingenuity. You probably did nicely.

What Flight 50 Means for the Ingenuity Mars Helicopter

Staff lead Teddy Tzanetos on the helicopter’s milestone aerial mission

Mars Helicopter Is Much More Than a Tech Demo

A Mars rover driver explains simply how a lot of a distinction the little helicopter scout is making to Mars exploration