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The Mars Helicopter Is Online and Getting Ready to Fly

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

#221

Post by johnwalkr »

contravariant wrote: post #127
tus89 wrote: post #123

Earlier quoted context omitted.

If we understand "flight" as being the use of a wing to generate lift in an atmosphere, then I think we can safely say this is the first time we have flown on another planet. I assume this little helicopter actually has rotary wings rather than fans.

If we're splitting hairs then the lack of control seems like a better criterion to distinguish the two. If you ask me there's no reason a zeppelin would be inherently less 'flighty' than a helicopter.

In the space industry, “flight” is used for all types of vehicles so I’d also argue to use that very broad definition rather than terrestrial terminology.

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

#222

Post by bananasbandanas »

ChuckMcM wrote: post #212
zhoujianfu wrote: post #204

Earlier quoted context omitted.

Does anybody have any thoughts on how feasible it would be to make a metal “vacuum sphere” that floated in earth’s atmosphere? That’d be pretty cool! How huge would it have to be? Would it have to be made of titanium? Aluminum? Stainless steel? How good are those materials at withstanding a vacuum (or partial vacuum) if the diameter was say... 50m? I feel like at some size it must work, as the volume of air displaced…

The challenge is that Earth's air isn't dense enough. That said, the math is "easy" density is volume/mass, vacuum adds no mass, so it is just material mass / volume. A 20cm diameter diamond sphere that was .5mm thick would have a mass of about 41g, a 20cm diameter sphere of air at sea level and "room" temperature is about 50g. So you would get 9g of "lifting force" from such a balloon (assuming I did all the calcula…

If you're interested in some fiction with this concept: In Neal Stephenson's 'Diamond Age' humans have mastered assembly of individual atoms in basically arbitrary ways. They use it (among other things) to create flying airships with an envelope made of diamond with a vacuum inside. Found it to be a fun read in general.

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

#223

Post by withjive »

thaumasiotes wrote: post #217
tempestn wrote: post #215

Earlier quoted context omitted.

Yes, but you could still construct it in orbit. Imagine building four quadrants, spooning them together for launch, then fusing ("cold welding") them into a sphere in space.

It is surely better to construct them here, where we have all our tools, and if really necessary pump them out here. There just isn't an advantage to doing it in space. You end up paying more to create a lower-quality sphere. And what weighs more - the air that got trapped in the sphere when we made it, or the machine we sent up to space to assemble a sphere there?

Seems quite short sighted to assume space manufacturing processes would not improve - or we would not want to improve them.

Cold weld it in space, it's not that difficult with some engineering.

Space X?

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

#224

Post by Kliment »

JoeAltmaier wrote: post #161
Robotbeat wrote: post #66

Earlier quoted context omitted.

How would it take-off and land without runways? VTOL flying wing designs have been proposed. But the first step is demonstrating any powered flight at all, which means helicopter.

Catapult of course! But then, only one takeoff. Which for some missions, would be enough.

robot arm on rover throwing it, and then rolling over to pick it up again

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

#225

Post by contravariant »

johnwalkr wrote: post #221
contravariant wrote: post #127

Earlier quoted context omitted.

If we're splitting hairs then the lack of control seems like a better criterion to distinguish the two. If you ask me there's no reason a zeppelin would be inherently less 'flighty' than a helicopter.

In the space industry, “flight” is used for all types of vehicles so I’d also argue to use that very broad definition rather than terrestrial terminology.

And even on Earth the term "flight" doesn't really care about the method, you've got 'balloon flights' for instance.

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

#226

Post by thaumasiotes »

withjive wrote: post #223
thaumasiotes wrote: post #217

Earlier quoted context omitted.

It is surely better to construct them here, where we have all our tools, and if really necessary pump them out here. There just isn't an advantage to doing it in space. You end up paying more to create a lower-quality sphere. And what weighs more - the air that got trapped in the sphere when we made it, or the machine we sent up to space to assemble a sphere there?

Seems quite short sighted to assume space manufacturing processes would not improve - or we would not want to improve them. Cold weld it in space, it's not that difficult with some engineering. Space X?

The assumption is that no matter how much space manufacturing processes improve, ordinary manufacturing processes will improve more than that.

This is pretty well guaranteed.

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

#227

Post by KuiN »

feralimal wrote: post #219

The mars atmosphere is equivalent to 120,000 feet. The record altitude for a helicopter on earth is 40,820 feet. How are helicopters able to fly so high on Mars? Also, parachutes do not open when the altitude is greater than 15,000 feet. How was the rover able to land at all with parachutes, in an atmosphere equivalent to 120,000 feet?

Phase 1 of the landing used parachutes to bleed off speed, but they aren't able to slow it enough for a soft landing. So a Skycrane was used for the second phase / touching down.

The blades on Ingenuity are larger (relative to the rest of the vehicle) and spin much faster than would be required on Earth.

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

#228

Post by KuiN »

dev_tty01 wrote: post #101
upbeat_general wrote: post #86

Earlier quoted context omitted.

I’m pretty sure this was one of the main criteria for building the helicopter since the -reject is not essential to the mission but is instead is a demonstration. It’s probably also why they’re waiting to fly it so that the rover is a bit further away

No it is still attached to the rover.

At the moment. Ingenuity is in a compartment on the underside of the rover and will be released onto the surface before flying.

Presumably they'll move the rover away to a safe distance before flying.

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

#230

Post by causality0 »

julienchastang wrote: post #93

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

It's actually not even the first time a powered aircraft has flown on Mars. Both Curiosity's and Perseverance's descent stages were powered aircraft that, after releasing the rovers, flew up and away from them in a controlled manner through the air.
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