Nasa proves its space helicopter can fly on Mars | Hacker News Reader

Nasa proves its space helicopter can fly on Mars

engadget.com

79 pointsoedmarap33 comments

While the unmanned aerial vehicle (UAV) only logged a total of one minute of flight time at an altitude of 2 inches above the ground, the scientists were able to get the data they need to be able to say that it will work on Mars. "The next time we fly, we fly on Mars," project manager MiMi Aung said.

I realise it's just a concept test for future missions, but this doesn't seem like a particularly rigorous test. I assume they are they under a lot of time pressure.

They (endgaget) were treating that test as the first and last proof. In reality, that project has been full-speed-ahead with flight tests for a while.

The difference is more like that this is the first untethered, full-flight-system, full-environment test. The data from which is compared to the huge batch previous tests with partial systems, w/ and w/o gravity offloads, etc etc.

Logging a lot of flight time with the actual hardware is a really bad idea, sort of like "testing in production."

>Logging a lot of flight time with the actual hardware is a really bad idea, sort of like "testing in production."

That's a fascinating fact. A lot of work must have gone into a testing environment that can do so much of the work via simulation.

>Logging a lot of flight time with the actual hardware is a really bad idea, sort of like "testing in production."

We test in staging environments set to mimic production 100% (or as close as possible) all the time.

After an initial period where they're under development, un-maned aerial vehicles should obviously be tested a hell of a lot in actual end environment, with their whole actual hardware, too.

>I realise it's just a concept test for future missions, but this doesn't seem like a particularly rigorous test.

It worked for Boeing.

I buy it. While the helicopter technology isn't currently developed by enough to do a flashy demonstration on Earth, the telemetry is developed enough to guarantee it will work on Mars with only that minimal test.

It's really cool. I am amazed they're able to fly a helicopter in what is effectively almost a vacuum to us.

But what about power? How long can a 4lb drone fly? a few minutes?

Presumably there's a way to recharge this thing, but that would require a base-station with solar or nuclear power source. I am not understanding how this drone would be effective in a mission!

Something I don't think people appreciate is how slowly things move on mars in general. Curiosity, a huge success, has moved a total of 20.38 kilometers as of two days ago. That's after 2359 martian days.

It's hard for me to imagine a drone not being effective!

https://mars.nasa.gov/msl/mission/whereistherovernow/?ImageI...

To be fair, though, a lot of that is by choice. What advantage is there in moving quickly and taking on all of the associated risks when there's lots to see and do while moving slowly and spending extended periods of time parked at specifically interesting sites?

By having alternate crafts that can move quickly, we might be able to better guesstimate if it's worth the time of the slow rover to change course and investigate a blip on the map. Alternatively, fast craft could fly around and drop beacons on areas of interest to be investigated at a later time. Beacons that could be sensor probes returning data of interest.

Tons of technical details on the helicopter here [0]

For power in particular, charged by solar panels (the things above the rotor), worst case end-of-life flight time is estimated at 90s, depending on season it might take more than 1 day to reach full charge.

Edit: And the two numbers for range I can find in that document suggest 300m flight range, and "outbound sorties" of length 100m (suggesting always flying back to the rover?).

[0] https://rotorcraft.arc.nasa.gov/Publications/files/Balaram_A...

I spoke to one of the project engineers at JPL’s Open House last year. He said the only planned mission for this unit is proof of concept. If they can make it fly on Mars they will be sending a bigger one with larger batteries and more instrumentation on a later mission. He said their constraint is his team has received a small allocation of antenna time during the overall mission. The 2020 Rover ops get priority.

I imagine based on past missions, probably after all objectives are achieved and time on the array is available, they’ll get creative and push the chopper a little more.

Not a rocket scientist, but I really wonder about the cost-effectiveness of this approach. Is it really more effective to do testing in prod (on another freaking planet) than to more thoroughly emulate the Martian atmosphere here first?

Emulating the martian atmosphere is easy enough, but the helicopter can't fly with martian atmosphere and earth gravity. And we don't really have good, cost effective ways to simulate lower gravity (at least none that work for flying drones). That really limits how much testing you can do on earth outside testing the subassemblies in isolation.

For anyone else wondering:

Earth gravity is 9.81 m/s^2, mars gravity is 3.72 m/s^2. To emulate this on earth you would have to be on a aircraft accelerating downwards at 6.09 m/s^2. Doing so starting at 0 vertical velocity for 90 seconds would mean loosing 24664.5 meters of altitude, ending at 548.1 m/s. The speed of sound is 340 m/s - so the only reasonable flight profiles (i.e. subsonic) probably involves starting out with ~274m/s vertical velocity, and doing a parabola where you get back to your starting point.

I'm not sure if you could actually maintain the necessary acceleration, and I imagine it would be difficult to maintain an atmosphere simultaneously, but it might be doable.

Maybe you have a partial vacuum chamber and the drone suspended by a winch that is tuned to reduce its effective weight to what it would weigh on Mars. A fairly complicated test setup, but cheaper than flying out to the red planet.

Unless you have a mission scheduled that can take a few more kilos of payload as is the case here.

It's more a risk assessment problem than a cost effectiveness problem. They're not going to get funded for a 50-100kg fully-instrumented UAV (and the boosters and spacecraft to get it to Mars) until they prove the concept first. The brass is willing to spend a half million on a mission that piggybacks on and minimally impacts a currently-funded mission to find out if UAVs are feasible. The reality is Opportunity has covered ~45 linear kilometers in its 14 year lifespan. They hope to cover hundreds of square kilometers with the UAV approach.

> but that would require a base-station with solar or nuclear power source. I am not understanding how this drone would be effective in a mission!

We have a very good track record of sending large rovers with solar and nuclear power sources to mars. A rover would make a good mobile base station, with a helicopter for collecting samples from various places to bring to the rover's onboard lab.

Side note: anyone tried to change his privacy settings on engadget.com? There seems to be a lot of bad ux at play.

Yes. They just do not enable you to do that. And do totally not comply with GDPR requirements this way. But non the less hope to come out unscathed because of their "opt in" popup.

Well. As I have a strong hosts file as well as respective browser addons I do not care - their trackers do not see me.

I've just stopped bothering. The intersection between "sites that use dark patterns to get around gdpr" and "sites with content I really need to get, and from them" is empty (in my sample)

Likewise. I'm much more likely to just go "meh" and close the tab if I hit some shitty cookie dialogue that makes me manually untick 37 options before continuing.

There are plenty of good sites out there who have either less or no tracking bollocks, I don't need to use the shitty ones.

Whenever I see the Oath pop up, I just close the site.

Same here. It's way beyond unacceptable; it's atrocious. I hope someone has the time and energy to pursue a GDPR complaint against them, as at least some Oath sites are clearly targeted at EU-based users.

Yeah.

> Before you continue...

> Engadget is now part of the Oath family. We (Oath) and our partners need your consent to access your device, set cookies, and use your data, including your location, to understand your interests, provide relevant ads and measure their effectiveness. Oath will also provide relevant ads to you on our partners' products. Learn More

> Select 'OK' to allow Oath and our partners to use your data, or 'Manage options' to review our partners and your choices. Tip: Sign In to save these choices and avoid repeating this across devices. You can always update your preferences in the Privacy Centre.

Not going to do that!

And from the Google cache link:

> 404. That’s an error.

> The requested URL /search?q=cache:lT5Qm1nXpPcJ:https://www.engadget.com/2019/03/29/nasa-proves-its-space-he... was not found on this server. That’s all we know.

But the Internet Archive has a good copy: https://web.archive.org/web/20190329140048/https://www.engad...

I've been using the Duck Duck Go Firefox extension. It seems to help a fair bit.

If you use Android then I strongly recommend Firefox, you can easily install ublock origin and other addons, and they even have an option to disable cookies altogether.. it's really a joy to use.

> They also had to use a gravity offload system in the form of a motorized lanyard that tugged at the helicopter as it hovered above the ground

This sounds like something that could make the helicopter more stable. Could a physicist please explain why it's still a good test?

They were probably just testing the thrust it puts out in that atmosphere by measuring the force applied to the tether.

They could also test the stability by trying to maintain a constant force on the tether (by not simply pulling as hard as possible), but I imagine they have different ways to test stability.

The concept is to have the object as the input and having ARGOS follow and adapt to make the object behave as if it were on another planet. If a person were testing for Mars, ARGOS would make a 100 pound barbell feel like only 38 pounds. Change the environment to Jupiter and the 100 pound barbell would feel like 240 pounds. It is designed to simulate conditions, not support what is already on Earth.

As for the helicopter, ARGOS had to adapt its weight relative to Earth by pulling it up enough to simulate lighter conditions on Mars.

I expect they probably anchored the tether to the center of gravity.

If this were the only test, that would be a bad test. They're probably verifying that the flight hardware has characteristics consistent with all the previous test cases before blasting it to Mars. (I work near this project, but not on it directly).

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