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The Mars Helicopter Is Online and Getting Ready to Fly

universetoday.com

171–180 of 265 posts

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#171
post #46

Does anyone know why they chose to send a helicopter and not some kind of plane or glider? I would've thought that a fixed-wing aircraft would have been simpler, lighter, faster and more efficient.

The helicopter makes up for thin atmosphere by rotating blades faster. Glider or a plane would have to move faster to get the necessary lift.

TBH in this environment I would make something that jumps like a flea instead :)

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#173
post #172

I wonder how they considered dust (dust storms) in their design of the mars helicopter.

They briefly talk about it in this Veritasium Video at around the 9 minute mark https://youtu.be/GhsZUZmJvaM

He says, unlike in the movies, it is not really an issue. With 1% earth’s atmosphere there is very little matter actually hitting you.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#174
post #105

Earlier quoted context omitted.

The moon is not a planet.

By many definitions the Earth-Moon system is a dual planetary system. The moon has more that 1% the mass of the Earth, which is by far the largest primary-secondary "not a planet" system in the solar system. Only not-a-planet Pluto and Charon exceed it. Also, Isaac Asimov considered the system a dual-planet system as the Moon's path around the sun is at no point convex nor retrograde.

Earth-Moon centre of mass is inside Earth, so, it's obvious that the Moon is orbiting the Earth, not both orbiting something else.

1% is an arbitrary threshold and solar orbit is dependent on external circumstances rather than the Earth-Moon system itself.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#175
post #134

Earlier quoted context omitted.

I'd argue Mars is still the most impressive. Rockets in no atmosphere is easy. Floating on Venus is easy because it has more atmo than any other rocky planet. Figuring out something that works well in Mars' thin (but still there) atmosphere, especially a helicopter , is really impressive. The celestial body classification is just a cherry on top.

Highly recommend looking at the specs of the helicopter. It masses just 1.4kg. Each blade is 35g!

Basically a DJI Phantom 4.

Edit: Phantom 4 is 1.3 kg and blades are 45g

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#176

Earlier quoted context omitted.

A consumer chip is a lot more likely to be permanently damaged by a "silver bullet" cosmic ray, though. Rad-hard chips don't just have shielding, they can also have redundant circuits and modifications to the foundry process. That said, I'm sure Ingenuity's processor is fit to purpose.

It's a bit of a shame that radiation hardened chips are stuck so far in the past. I believe the volume is so low it does not warrant the investment to make radiation hardened versions more often.

Parts of hardening include enlarging physical features and increasing operating voltage

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#177

Kinda curious those "pointy counterweights?" near the hub of the rotors, why are those there? Looks like they'd run into each other? It looks like it has full collective/cyclic on both levels.

Not sure about the counter-weights, but without a tail rotor, I'm pretty sure it requires either a collective on both levels, or else software to navigate properly when the body is spinning, and some mechanism to allow it to safely land while the body is spinning.

The torque to spin the rotor changes with the blade angle, so to keep the counter-rotating torques balanced, they need to control blade pitch on both. I suppose the blade drag is a non-linear function of blade angle, so technically they might be able to keep the torques balanced with cyclics on both and a collective only on one, but it's certainly much more simple to have at least collectives on both.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#178
post #84

Earlier quoted context omitted.

As the name RAD750 indicates, that processor is designed to be radiation hardened which matters for longer missions. I doubt the Snapdragon 801 will survive as long or have as few errors but it also doesn't matter since Ingenuity isn't aimed for long term usage.

What I imagine for long lived and high-cost missions is using some sort of co-processor setup with a radiation hardened processor and a faster and more modern processor. These rovers run a lot of computer vision algorithms and I believe more powerful hardware would be quite useful. They may already do something like this, however my understanding is that there is a lot of skepticism in integrating these less fault-to…

Do keep in mind that radiation cause permanent damages at predictable paces... I don’t understand why online discussions like this fails to address permanent damages. You can’t reset burnt chips.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#179
post #177

Kinda curious those "pointy counterweights?" near the hub of the rotors, why are those there? Looks like they'd run into each other? It looks like it has full collective/cyclic on both levels.

Not sure about the counter-weights, but without a tail rotor, I'm pretty sure it requires either a collective on both levels, or else software to navigate properly when the body is spinning, and some mechanism to allow it to safely land while the body is spinning. The torque to spin the rotor changes with the blade angle, so to keep the counter-rotating torques balanced, they need to control blade pitch on both. I su…

Yeah I don't know enough myself. I wonder if you could use drag change on one and rpm change on the other, maybe balance out in terms of lift.

But yeah maybe those pointy things are just weights/for aerodynamics.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#180

Fun fact: This is not the first time a space program has flown on another planet. The Soviets launched weather balloons on Venus during the Venera missions [1] [1] https://en.wikipedia.org/wiki/Vega_program#Balloon

And given the density of Venus' atmosphere, here is a fun thought experiment. It may be possible to make 'titanium' balloons for longer term operation. The would work by creating the balloon envelope on earth, have a sealing mechanism that you activated in orbit so they had vacuum inside. And then drop them into the atmosphere. Same idea a glass floats on fishing nets[1] except with titanium (so they can withstand th…

Venus’s atmosphere is 100x denser than earth’s, so you could just seal the metal balloons at sea level pressure and it wouldn’t really make a difference. Or you could seal them in a vacuum on earth. Not sure why you would need to feel them in space.
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