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JPL's Plan for the Next Mars Helicopter

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Re: JPL's Plan for the Next Mars Helicopter

#41

Post by rtkwe »

barbegal wrote: post #37

For me, the value of ingenuity has not been the fact that it flies but rather that is designed to be operated in a far more risky way than a traditional rover. A mission that consisted solely of a single larger helicopter would be far more risk averse. It would travel shorter distances, move slower and have so much redundancy built in that there is likely to be little mass dedicated to the scientific instruments.

The issue is it has to be pretty big to carry much in the way of scientific instruments to begin with. Right now there's no scientific instruments on Ingenuity beyond the camera and that is only really useful for surveying the ground. Also Ingenuity can be risky because it's goal is to test the craft itself so they take risks with it to see how well the design performs at the edges of it's flight envelope.

Re: JPL's Plan for the Next Mars Helicopter

#42

Post by JoeAltmaier »

Lots in here, taking me time to unpack.

Kind of blue-sky - 30kG is heavy, so maybe its all moot - who's going to dedicate that much mass to this project.

Any geology it does, will be contaminated by rotor wash scrubbing the surface material when it lands. Is that an issue? Maybe its a benefit.

Can it really react to sample inaccessible places? What is the response time between capturing an image of a face, and getting a response from Earth saying "take a sample!"? Is it even within the battery life/flight time?

Can it range outside the rover line of sight? What about radio relay to the orbiter? Surely it can't track that itself, especially in flight. That level of independence may be a pipe dream.

I'm in favor of a drone element to the next mission, as long as it doesn't instantly get lost or broken.

Re: JPL's Plan for the Next Mars Helicopter

#43

Post by modshatereality »

FreeFull wrote: post #18
dogma1138 wrote: post #14

Wouldn’t an airship be a more viable option for a long term mission on Mars?

I imagine with Mars's thin atmosphere, it'd be hard to get enough buoyancy to lift off.

It won't work at high altitude until we start polluting there. What is air density in one of those nice big craters though?

Re: JPL's Plan for the Next Mars Helicopter

#44

Post by dylan604 »

"You'd shoot a little projectile from the drone that embeds itself in the cliff wall, and then you'd reel it back in with a sample."

Is that what would happen? How does the embed de-embed itself? How does the reeling in not end up pulling the drone closer to the cliff?

Re: JPL's Plan for the Next Mars Helicopter

#45

Post by rtkwe »

dogma1138 wrote: post #30
trothamel wrote: post #22

Earlier quoted context omitted.

Airships seem somewhat vulnerable to the weather, in practice, as they're always flying. A nice thing about a helicopter is you can land, and it's a station until you take off again.

The weather isn’t that of an issue due to the thin atmosphere. You can land an airship by compressing the lifting gas into a liquid. If you can get enough power reserve at least to do that. The main issue would be the size of the balloon but honestly if we can make some origami rigid airframe a vacuum airship might actually work. At that point controlling buoyancy is also less of an issue from a power perspective sin…

In general trying to create a vacuum airship is a loosing game because you have to add so much support to prevent it from collapsing that you can't win the race between volume and weight to achieve buoyancy. The thinner atmosphere is a bonus to decreasing the force for a given volume but you simultaneously have to increase the size of the 'balloon' since it's displacing less air for every unit of volume so it has to get bigger which increases the surface area further.

Doing some quick math using the ideal shape of a sphere: Mars surface atmosphere is ~1/60th as dense as the Earth's so you'll wind up with 23x the surface area which at the reduced surface pressures of mars you'd be looking at around 15% of the total forces you'd have to resist. For a sphere that might just push it into the realm of possible options but to get to a 'pure' vacuum you need very fancy and heavy pumps that need cryogenic cooling beyond the difficulty of doing this with an actual blimp shape.

Re: JPL's Plan for the Next Mars Helicopter

#46

Post by polynomial »

dylan604 wrote: post #44

"You'd shoot a little projectile from the drone that embeds itself in the cliff wall, and then you'd reel it back in with a sample." Is that what would happen? How does the embed de-embed itself? How does the reeling in not end up pulling the drone closer to the cliff?

mainly, precise tolerance engineering.

ofc we don't already know the exact composition and hardness of said cliff walls, so your question stands.

Re: JPL's Plan for the Next Mars Helicopter

#48

Post by jvanderbot »

dogma1138 wrote: post #32
jvanderbot wrote: post #19

Earlier quoted context omitted.

The atmo is very thin, making the balloon huge relative to the gondola. Some people are quite enthused about it anyway. Including myself. http://www.gaerospace.com/space-exploration/planetary-aerobo... With a thick atmo, plenty of sun, and not too much heat / cold in the upper layers. Venus is a _great_ place for balloons. https://www.nasa.gov/vision/universe/solarsystem/venus-20070...

I was thinking about a rigid body vacuum airship, landing would be easy because all you need to do is lose the vacuum which can be done with a valve and cost no power. Taking off again can be done over days so you can power it with solar panels if you can’t fit an RTG. I honestly don’t think winds would be that much of an issue they won’t be strong enough to structurally damage the airship they’ll blow it off sure bu…

And how would that be packed into a landing shell?

Re: JPL's Plan for the Next Mars Helicopter

#49

Post by jbay808 »

dogma1138 wrote: post #32
jvanderbot wrote: post #19

Earlier quoted context omitted.

The atmo is very thin, making the balloon huge relative to the gondola. Some people are quite enthused about it anyway. Including myself. http://www.gaerospace.com/space-exploration/planetary-aerobo... With a thick atmo, plenty of sun, and not too much heat / cold in the upper layers. Venus is a _great_ place for balloons. https://www.nasa.gov/vision/universe/solarsystem/venus-20070...

I was thinking about a rigid body vacuum airship, landing would be easy because all you need to do is lose the vacuum which can be done with a valve and cost no power. Taking off again can be done over days so you can power it with solar panels if you can’t fit an RTG. I honestly don’t think winds would be that much of an issue they won’t be strong enough to structurally damage the airship they’ll blow it off sure bu…

I'm not aware of any vacuum container that is strong enough to resist buckling while being light enough to be buoyant.

Re: JPL's Plan for the Next Mars Helicopter

#50

Post by aboodman »

tablespoon wrote: post #47

30kg flying on Mars? Wow! How massive is this thing gonna be. Ingenuity is already 1.2 metres across, so it’s not exactly small. This thing is gonna be massive.

> 30kg flying on Mars? Wow! How massive is this thing gonna be?

It’s gonna be 30kg =P

…

I’ll show myself out.

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