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Nasa will send helicopter to Mars to test otherworldly flight

bbc.com

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Re: Nasa will send helicopter to Mars to test otherworldly flight

#111

Post by cududa »

pvaldes wrote: post #108

Looks like a more efficient and much faster way to explore the area if they can solve the thinner atmosphere but, if their missions are autonomous and it seems that can't be modified in real time, what happens with the mars storms? I hope that they have a software to take measures if the air pressure or the light levels change suddenly. Couldn't the differences in temperature between shadowed and sunny areas create t…

Yes to all of this but do you assume no one at NASA has thought of any of this? Weird.

Re: Nasa will send helicopter to Mars to test otherworldly flight

#112

Post by SamReidHughes »

jacquesm wrote: post #90
TeMPOraL wrote: post #86

Earlier quoted context omitted.

> round-off errors regarding the timing would make all satellites appear at the same point in space when looked at from Mars Not just timing, also space - Earth is a fraction of an arc second on Martian sky, pretty much a very small dot. All your signals would be coming from that small dot, i.e. practically on top of one another.

The whole idea of GPS is to turn a very good time reference (an atomic clock) into a space reference, by using multiple such references with known locations at once and then to send out time stamped signals. If you can't distinguish arrival times the signal origins collapse into a point. The travel time of the signal from Earth to Mars is anywhere from 4 to 24 minutes (assuming you have line of sight, which isn't the…

I'm pretty sure if you're on the Earth's surface and can pick up three GPS satellites, the other solution is out in space. If you see four or more GPS satellites, there's a unique solution.

Re: Nasa will send helicopter to Mars to test otherworldly flight

#113

Post by pmoriarty »

djsumdog wrote: post #71
sktrdie wrote: post #20

So if it falls on its side, something that has a probably a 50% chance of happening, can it get back up? I always thought that for exploring another planet, you shouldn't really use something with wheels or wings. Something different like small "jumping robots" would make a lot more sense in a place where you have literally the ability to do 0-hardware maintenance. Instead of a single expensive flying robot, why not…

OMG that little jumping robot is so cute!

I don't know.. I shudder every time I see a robot from Boston Dynamics, because I always imagine it with weaponry running/rolling down the street and killing people, with people trying to fight back but being mostly ineffective.

It's likely we'll see some nightmare uses for such technology in our lifetimes.

Re: Nasa will send helicopter to Mars to test otherworldly flight

#114

Post by PhasmaFelis »

djsumdog wrote: post #68
chiefalchemist wrote: post #22

Earlier quoted context omitted.

"The helicopter uses counter-rotating coaxial rotors about 1.1 m in diameter..." Not to be little it but, in short, a drone. I presume the rocket scientists are jealous ;)

That's what I thought too. But they've been designing this for years; so it might have started before drones got as popular as they are. I mean, drones are just a new name for hobby aircraft. People typically associate drones with quad-copters, but people were flying tiny helicopters next to their small replica remote aircraft for decades. I realize the FAA has official designations for what is a drone (and a lot of…

It's always struck me, when people are panicking about some overwrought news story, how much scarier R/C helicopters are when you call them "drones".

Re: Nasa will send helicopter to Mars to test otherworldly flight

#115

Post by pasbesoin »

KineticLensman wrote: post #17

Link to the underlying press release [0] which has slightly more info than the BBC article. There is a bit more background about the project at [1], with some key points being: "The helicopter uses counter-rotating coaxial rotors about 1.1 m in diameter. Its payload will be a high resolution downward-looking camera for navigation, landing, and science surveying of the terrain, and a communication system to relay data…

It would have to be pretty dust/debris resistant, but could the helicopter -- or a simplified version of it -- be used to clear a lander's solar panels of dust?

I recall with previous landers, how solar charging performance would degrade, then pick up after what was surmised to have been a wind storm event.

Re: Nasa will send helicopter to Mars to test otherworldly flight

#116

Post by skykooler »

ambicapter wrote: post #89

Does this make any sense? Isn't Mars' atmosphere much thinner than Earth's? Wouldn't that count against using rotary wing crafts?

The interesting thing about rotary-wing craft is that they actually work sort of independent of altitude (as long as everything stays subsonic.) As air pressure decreases, lift at a given rotor RPM decreases - but the drag on the rotor also decreases, so the RPM increases and it ends up providing the same amount of thrust. The reason helicopters on Earth haven't flown very high is not because of the rotors, but rather the engines, which require more air than is present at high altitude. For electric motors, that is not a problem.

Re: Nasa will send helicopter to Mars to test otherworldly flight

#117

Post by microcolonel »

Interesting that they didn't go the multirotor route, seems like it would cut down on development, complexity, and possibly weight. Maybe single axis counter-rotor was chosen for having a slightly better area/diameter to lift generating area ratio.

Re: Nasa will send helicopter to Mars to test otherworldly flight

#118

Post by sgc »

chiefalchemist wrote: post #61
sgc wrote: post #36

Earlier quoted context omitted.

Of course. It's by definition until we get someone to Mars.

I hear ya. But at 1.1m lifting an adult human might be a struggle.

Right, of course you got that. I just wanted to point out that we need to manage our expectations of such a headline due to the current state of technology. There is no way an earth-size helicopter is making it to Mars with current rocket capabilities. The thing is the size of a softball and requires those 1.1m rotors. A human carrying copter would be pointless it seems. They will probably use rocket powered hoppers or something along those lines

Re: Nasa will send helicopter to Mars to test otherworldly flight

#119

Post by jacquesm »

SamReidHughes wrote: post #112
jacquesm wrote: post #90

Earlier quoted context omitted.

The whole idea of GPS is to turn a very good time reference (an atomic clock) into a space reference, by using multiple such references with known locations at once and then to send out time stamped signals. If you can't distinguish arrival times the signal origins collapse into a point. The travel time of the signal from Earth to Mars is anywhere from 4 to 24 minutes (assuming you have line of sight, which isn't the…

I'm pretty sure if you're on the Earth's surface and can pick up three GPS satellites, the other solution is out in space. If you see four or more GPS satellites, there's a unique solution.

That's probably correct. I read up on GPS years ago and I remember that one of the possible solutions is intuitively wrong for a surface of the earth measurement and filled that in mentally as 'inside the earth', but out in space sounds much more logical and likely.

Re: Nasa will send helicopter to Mars to test otherworldly flight

#120

Post by dredmorbius »

pasbesoin wrote: post #115
KineticLensman wrote: post #17

Link to the underlying press release [0] which has slightly more info than the BBC article. There is a bit more background about the project at [1], with some key points being: "The helicopter uses counter-rotating coaxial rotors about 1.1 m in diameter. Its payload will be a high resolution downward-looking camera for navigation, landing, and science surveying of the terrain, and a communication system to relay data…

It would have to be pretty dust/debris resistant, but could the helicopter -- or a simplified version of it -- be used to clear a lander's solar panels of dust? I recall with previous landers, how solar charging performance would degrade, then pick up after what was surmised to have been a wind storm event.

A dusting brush would likely be more mass- and energy-efficient.
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