What Flight 50 Means for the Ingenuity Mars Helicopter

JPL’s Ingenuity helicopter is getting ready for the fiftieth flight of its 5-flight mission to Mars. Flight 49, which befell final weekend, was its quickest and highest but—the little helicopter flew 282 meters at an altitude of 16 meters, reaching a high pace of 6.50 meters per second. Not a nasty efficiency for a tech demo that was alleged to be terminated two years in the past.

From right here, issues are solely going to get harder for Ingenuity. Because the Perseverance rover continues its climb up Jezero crater’s historical river delta, Ingenuity is attempting its finest to scout forward. However, the winding hills and valleys make it troublesome for the helicopter to speak with the rover, and thru the rover, to its workforce again on Earth. And there isn’t quite a lot of time or room to spare, as a result of Ingenuity isn’t allowed to fly too near Perseverance, which means that if the rover ever catches as much as the helicopter, the helicopter might must be left behind for the rover’s personal security. This high-stakes race between the helicopter scout and the science rover will proceed for kilometers.

“Two years in, 10 kilometers flown, and we’re nicely over an hour now within the skies of Mars.”
—Teddy Tzanetos, NASA

For the Ingenuity workforce, this new mode of operation was each a problem and a possibility. This was nothing new for people who’ve managed to maintain this 30-day know-how demo alive and wholesome and productive for years, all from a pair hundred million kilometers away. IEEE Spectrum spoke with Ingenuity Staff Lead Teddy Tzanetos at JPL final week about whether or not flying on Mars is ever routine, how they upgraded Ingenuity for its prolonged mission, and what the helicopter’s success means for the way forward for airborne exploration and science on Mars.

IEEE Spectrum: Is 50 flights on Mars a milestone for you of us, or are issues routine sufficient now that you simply’re it as simply one other flight?

Teddy Tzanetos: It’s massively significant. We’ll come again to the routine query in a second, however it’s very significant for all of us. Once we hit 10 after which 25 it was huge, however 50 is a fairly severe quantity now that we’re 10X our preliminary flight depend. Two years in, 10 kilometers flown, and we’re nicely over an hour now within the skies of Mars. So hitting flight 50, it’s a giant factor—we’re in all probability going to arrange a cheerful hour and have a giant social gathering for the workforce.

Are you able to speak about a few of the new challenges that Ingenuity has been going through because it makes its approach up Jezero Crater’s river delta together with the Perseverance rover?

Tzanetos: The core of the problem right here is that the paradigm has modified. If you have a look at the primary 12 months of Ingenuity’s prolonged operations, we had been nonetheless within the Three Forks space, the place the bottom was flat. We might get line of sight from the helicopter to the rover from a whole bunch and a whole bunch of meters away. Our longest hyperlink that we established was 1.2 kilometers—an enormous distance.

After which we began to appreciate that the rover was going to enter the river delta in like six months. It’s going to begin climbing up by dozens and dozens of meters of elevation change and passing by ravines, and that’s going to begin presenting a telecom problem for us. We knew that it couldn’t be enterprise as traditional anymore—if we nonetheless wished to maintain this helicopter mission going, not solely did we have to change the way in which we had been working, however we additionally needed to change the helicopter itself.

“We owe it to everybody who labored on Ingenuity and everybody who will proceed to work on rotorcraft on Mars to try to get every thing out of this little spacecraft that we are able to.”
—Teddy Tzanetos, NASA

This realization culminated in essentially the most difficult flight software program improve we’ve ever performed with Ingenuity, which occurred final December. We went into the heart of our algorithms and added two new options. One was the power to detect and react to touchdown hazards from the air, which concerned handing over just a little little bit of autonomy again to Ingenuity, with the power to inform it, “Fly to your terminal waypoint and try to land the place we predict is sweet, based mostly off of orbital imagery. However in case you have higher info out of your photographs than what we people had right here on Earth, and also you see a hazard, decide a safer web site and land there as a substitute.” In order that’s one big change in what’s taking place now. And we’d like that on the river delta as a result of we’re now not flying in a car parking zone—in addition to the problem of the elevation change, the terrain is totally different as nicely, with extra, bigger rocks that Ingenuity must keep away from.

The second characteristic that we added was to incorporate details about the terrain to Ingenuity’s navigation filter. Once we designed Ingenuity, we assumed we had been solely going to be deployed on the flat terrain of Three Forks. Subsequently, any change within the laser altimeter measurement we might belief to be an actual change within the movement of the helicopter, or we might at the least filter that into our altitude knowledge. However that’s now not the case. Now, as Ingenuity flies, if the altimeter sees a giant lower in elevation, that could possibly be as a result of the bottom is rising to satisfy us somewhat than as a result of we’re transferring down. So since December, we’ve been telling Ingenuity in regards to the elevation profile throughout its supposed flight in order that it is aware of what the bottom is doing beneath it.

Now that each the rover and the helicopter have begun the river delta climb, we’re additionally paying very shut consideration to our telecom hyperlink finances maps. You possibly can think about each hill or rise that would occlude the road of sight between the helicopter antenna and the rover antenna can have a big effect in your telecom hyperlink, and we’ve fantastic maps from orbit the place we are able to decide a possible touchdown level and propagate our radio hyperlink finances calculation throughout that time.

We’re attempting to plan these flights as aggressively as we are able to to ensure that we keep forward of Perseverance. We don’t wish to run the danger of getting a state of affairs the place the rover may have to attend for Ingenuity—that’s not a superb factor for anyone. However we additionally wish to present worth for the rover by scouting forward, and what we hope to do on Flight 50 is to get some imagery of Belva crater, which is that this stunning huge crater to the north of the place Ingenuity presently is. We’re going to get views that the rover workforce wouldn’t be capable of present for the science workforce, and it’s actually thrilling for us when there are these moments which are uniquely pushed by Ingenuity’s functionality. We wish to go after these, as a result of we wish to present that worth whereas she’s nonetheless wholesome. Whereas we nonetheless can. We owe it to everybody who labored on Ingenuity and everybody who will proceed to work on rotorcraft on Mars to try to get every thing out of this little spacecraft that we are able to.

“Among the best hallmarks of know-how success is if you don’t notice it, or when it turns into boring. Which means the know-how is working, and that’s an exquisite feeling.”
—Teddy Tzanetos, NASA

At one level, NASA was very clear that Ingenuity’s mission would come to an finish in order that Perseverance might transfer on to deal with its major mission. However clearly, Ingenuity continues to be flying, and nonetheless maintaining with the rover. Not solely that, however we’ve heard from a rover driver how priceless it’s to have Ingenuity scouting forward. With that in thoughts, as Ingenuity navigates this difficult terrain, will there be any flexibility if one thing doesn’t go fairly proper, or will Perseverance simply depart the helicopter behind?

Tzanetos: We’ve got to take a look at the large image. An important factor at this level is for Perseverance to gather samples and do science. In case you have a look at every thing that must be performed throughout all the rover’s science payloads, each sol [Martian day] is valuable. And the helicopter workforce understands that.

We’re doing our greatest to change into extra environment friendly, and I feel that’s a giant win that we don’t have fun sufficient on the Ingenuity workforce internally—how rather more environment friendly we’re right this moment in comparison with the place we had been two years in the past. Earlier, you talked about flying turning into routine. I feel the workforce has succeeded in doing that, and I’m extraordinarily pleased with that accomplishment. Among the best hallmarks of know-how success is if you don’t notice it, or when it turns into boring. Which means the know-how is working, and that’s an exquisite feeling.

There’s what’s known as a tactical window that we’ve between the downlink of the final sol’s exercise and when we have to uplink exercise for the subsequent sol, which is anyplace from 5 to 10 hours. A sure cadence of actions must happen throughout that window, and we have to cross sure checkpoints to get our knowledge uploaded and radiated by the Deep House Community in time. We’ve labored very, very laborious to attenuate our footprint on that timeline, whereas additionally being reactive in order that we are able to transfer rapidly on any last-minute adjustments that the rover workforce wants us to accommodate. We’ve got to get in, fly, and get out.

Anomalies will occur. That’s simply the character of Mars. However when these moments happen, the helicopter and rover groups again one another up. To be clear, nobody on the helicopter workforce needs to trigger a delay for the rover. All of us need the rover to satisfy its mission, get its samples, and get the science performed. If we’ve a severe anomaly, we’ll must take that one sol at a time. We’re going to strive as laborious as we are able to to ensure we are able to hold pushing this little child so far as we are able to whereas nonetheless engaging in the core science mission.

NASA’s Ingenuity Mars Helicopter takes off and lands on this video captured on April 19, 2021, by Mastcam-Z, an imager aboard NASA’s Perseverance Mars rover. This video options solely the moments of takeoff and the touchdown—and never footage of the helicopter hovering for about 30 seconds.NASA/JPL-Caltech/ASU/MSSS

How do you steadiness threat to the helicopter towards exploration and science targets, or attempting new issues like pushing Ingenuity’s flight envelope?

Tzanetos: That’s the enjoyable half! There’s no instruction guide. The best way we do it’s we’ve a cellphone name with the core folks on the workforce, and everybody simply shares their opinions. The very best precedence for us is getting some good scouting imagery for the scientists and rover drivers—we bounce at these alternatives. If we’re flying by a bit of terrain that isn’t notably fascinating, that’s once we begin wanting on the flight envelope developments, proper? With flight 49, we’re going increased than we ever had earlier than and flying quicker than we ever have earlier than. That’s not a request from the science neighborhood or the rover planners; that’s coming from our personal inner workforce the place we’re attempting to launch functionality piece by piece because the flights go on, as a result of each time we get that win, it’s a win for the pattern restoration helicopters. So there’s that ever-present strain to push more durable, push quicker, push increased. And let’s additionally get some fantastic scouting knowledge alongside the way in which once we can.

What have you ever discovered about flying helicopters on Mars from 50 flights, that you’d do not know about in case you’d been in a position to do exactly 5 flights?

Tzanetos: Tons of issues. Since I simply talked about flying quicker and flying increased, and we’ve now legitimately expanded Ingenuity’s flight envelope. There’s the lifetime argument, which is clear—this design has lasted for much longer than anybody might have anticipated, even simply by way of elements and workmanship. Every certainly one of Ingenuity’s practically a thousand solder joints had been soldered by technicians at JPL who’ve essentially the most blessed, exact arms. We’d designed Ingenuity to fly in springtime on Mars, however through the Martian winter, for greater than 200 sols the temperature cycled between 20°C and -90°C and again once more. Finally, it bought so chilly that Ingenuity’s battery would die each night time, the heater would cease operating, and every thing would freeze. That was an enormous curveball that we needed to deal with, however due to the workmanship of these folks, Ingenuity was in a position to survive.

“We now have a stake within the floor to say, ‘Off-the-shelf works, we are able to belief this stuff.’”
—Teddy Tzanetos, NASA

Additionally, mud. We knew that mud would choose Ingenuity’s photo voltaic panel, however we’ve proven that by the method of flying, there’s some type of impact that’s serving to us to maintain our panel clear. It’s troublesome to place a finger on precisely what it’s—perhaps the vibration of flight, or the downwash of air passing over the photo voltaic panel and into the rotors, or the oncoming air as we transfer ahead. And it wasn’t simply the mud on the panels; we additionally bought mud in our actuators. Final 12 months, Ingenuity weathered a giant mud storm, and afterwards once we tried checking our management surfaces, issues didn’t look good. The motor currents had been approach too excessive, and we had been left scratching our heads, attempting to determine what to do. We didn’t have mud boots across the rotor system just because we had thought, “we’re solely going to be working for 30 days, we don’t want them.”

Our companions at AeroVironment [who worked with JPL on the Mars helicopter design] had one of many swash plate mechanisms mendacity round, so that they spoke to our geologists to determine what sorts of mud particles might need gotten blown into the swash plate on Mars. We despatched them some simulated Mars mud, and so they threw it on the swash plate, after which did an experiment to determine what number of occasions they wanted to cycle it earlier than it began to function correctly. Seven cycles bought many of the mud out, so we tried that on Mars, and it labored. So now we’ve a brand new software in our software belt: we all know easy methods to clear ourselves. That’s big. And we wouldn’t have found out any of this stuff had we not gone previous 5 flights.

Trying on the Mars pattern return helicopters, how a lot of their design has been made potential by the truth that Ingenuity has been in a position to fly this lengthy, and reply these questions that you simply may not have even thought to ask?

Your entire design. I don’t suppose we’d be speaking about pattern restoration helicopters if Ingenuity didn’t fly, interval, and if it hasn’t survived for so long as it has. You might have to bear in mind, Ingenuity is a tech demo. These pattern restoration helicopters are an actual a part of the mission now. If Perseverance has an anomaly within the subsequent decade, these helicopters are the backup—they must work. And I’m certain that Ingenuity’s two years of prolonged operations supplied the proof essential to even begin speaking in regards to the pattern restoration helicopters. In any other case, it might be loopy to suppose, “let’s go from tech demo to a part of a category B mission inside a 12 months.”

That’s superb. It should really feel actually good for you of us to have fully modified what the pattern return mission appears like due to how profitable Ingenuity has been.

Completely. I personally thought to myself, “Hey, that is nice, Ingenuity has been doing a terrific job, and this will likely be fantastic knowledge for the subsequent time we ship a rotorcraft to Mars.” Which I assumed was going to be like ten years later—I assumed that Mars pattern return would occur with a rover, after which perhaps after that, we might throw some helicopters on Mars, perhaps a hexacopter with some science payloads on it. By no means in my wildest desires did I ever suppose, whereas we’re nonetheless flying Ingenuity, that we’d be designing the subsequent helicopter mission based mostly on Ingenuity to go to Mars.

Extra broadly, how has Ingenuity influenced NASA’s method to robotics?

From a robotics perspective, I hope one of many long-lasting impacts of Ingenuity is the adoption of economic off-the-shelf know-how into extra NASA missions, and different non-NASA missions into area. This was the primary time we flew a cellphone processor, not as a result of we liked the thought about utilizing a component that wasn’t radiation hardened, however as a result of we had been pressured to. We wanted a high-throughput processor, and the one approach to try this and be light-weight sufficient was to make use of a cellphone chip. There was quite a lot of concern about that—we did some preliminary testing, however on condition that we had been a tech demo, which implies high-risk, excessive reward, we might solely accomplish that a lot. And right here we’re, two years later, with this Snapdragon Qualcomm processor that’s been operating for 2 years on the floor of Mars, to not point out all the opposite parts just like the IMU, the digicam, the battery, the photo voltaic panels. I feel that’s one of many unsung victories of Ingenuity. We now have a stake within the floor to say, “Off-the-shelf works, we are able to belief this stuff.” And we are able to make a stronger argument for the subsequent mission to essentially allow your engineers and your scientists to have rather more know-how on board than the rest we’ve despatched into area.

Ingenuity will try Flight 50 any time now, with the objective of touring 300 meters to the opposite facet of a ridge. The touchdown web site might make it troublesome to know whether or not the flight was profitable till Perseverance catches up a bit, however we hope to listen to the excellent news inside the subsequent few days.