Robert Zubrin's Mars Gashopper Airplane

Fraser Cain writes "Universe Today has a story about Robert Zubrin's (Mars Society President) Martian Gashopper Aircraft proposal to NASA. It uses solar power to liquefy carbon dioxide and then use it as a propellant to take off, fly hundreds of km above the surface of Mars like an airplane, and then land vertically again."

Comments

Here and now?

[FractiousWeasel]

Is it possible to use this technology here on Earth? We certainly have the carbon dioxide for the fuel. Are higher temperatures or gravitational forces a showstopper?

Re:Here and now?

[stratjakt]

The limiting feature of the gashopper is the electricity required to pressurize and heat the carbon dioxide propellant. This process consumes a lot of power, and the gashopper would need more than a month using its solar cells to refuel and recharge its batteries before it could take off again.

I guess if you only travelled a few hundred yards a month, it might work.

I'm pretty sure gravity is an issue, though. Gravity's a real bitch. Newton should never have invented it. Or he should have at least patented it so noone could use it.

Re:Here and now?

[Clay Pigeon -TPF-VS-]

The Carbon dioxide is much more concentrated on Mars than on Earth. It would take a lot longer to get enough for fuel, and you would need more propellant to overcome Earth's larger gravity.

Re:Here and now?

[Egekrusher2K]

They've done test flights here on Earth, so I'm assuming it works here.

Re:Here and now?

[realdpk]

The global warming people indicate that carbon dioxide is a major problem and is coming from factories and the like. Could they not cap off the factory chimnies or whatever (I honestly don't know) and at least try to do something useful with it?

Re:Here and now?

[InfiniteWisdom]

I don't think CO2 is essential to the system... it just happens to be the most handy gas available on mars. Its really like a VTOL aircraft with jet engines except that the gas is heated electrically rather than by burning fuel. An earth-based gashopper would just use air.

Re:Here and now?

[thinkstoomuch]

CO2 has a relatively warm freezing point, -78C, compared with -196 for nitrogen, and -182 for oxygen. So, it's convenient for that reason too. I'm sure you could make a similar system for our atmosphere, though liquid nitrogen is trickier to deal with than CO2.

Re:Here and now?

[Fortran IV]

Interesting question. From the article: The simplest gashopper could actually be quite light, as little as 50 kg (110 pounds). That's using Earth gravity conversions. The same 50 kg would weigh about 41 lbs on Mars.

But this little beast will use most of its propellant on forward motion, and acceleration relates to mass, not weight. Density of atmosphere will be the other factor, affecting the amount of lift the wings generate.

Re:Here and now?

[r00zky]

> The same 50 kg would weigh about 41 lbs on Mars.

Do martians use the imperial system now?

For the imperial impaired (like me) 41 lbs == 18,6 kg

Re:Here and now?

[Fortran IV]

Problem is, kilograms are properly a unit of mass, not weight (or force). Mars has about 3/8 the surface gravity of Earth (I think), so something that weighs (exerts a downward force of) 88 lbs on Earth weighs about 33 lbs on Mars. But it will still have a mass of about 40 kg.

Re:Here and now?

[Spetiam]

Yeah, but I'd award them the contract just because the of the name. "Gashopper." Heh.

Ok, I need to find some work to get done...

Re:Here and now?

[r00zky]

Ok, weight should be expressed in Newtons like any other force.

F = m * a
Just multiply for 9,8 here in Earth and for 9,8 * 3/8 (or whatever) in Mars.

Re:Here and now?

[PabloD]

If you let it roam around earth a little bit, it will get most likely stolen ;-)

Re:Here and now?

[Vulcann]

The question one must focus on is that WHAT does burning CO2 produce ? If it produces CO as one of the byproducts, we arent necessarily improving the situation much - CO is a lethal gas for human beings. On a place like Mars where you dont have to worry about poisoning humans no one could care less but the same doesnt apply on earth.

Interesting

[over_exposed]

While the mobility is an interesting concept (being able to move 100+ km at once), how does this change the vehicle's ability to analyze more area? The other crafts "can only examine a few square metres of ground"... at a time. But then it moves and does it again... The only differences I see is that the gashopper does it's analysis of the "few square metres of ground" then hops ~100km away only to analyze a "few square metres of ground." How is this spotty analysis better than continuous examination? Maybe it could be used in conjunction with other crafts of old style. The gashopper gets sent to interesting locations to determine if they should send a more traditional land-based craft? One thing is does have going for it is the ability to refuel itself.

Re:Interesting

[Egekrusher2K]

You're correct in one aspect, that it can only examine a small area at a time. However, with this new vehicle, they aren't limited to one geographical feature set. With the rovers, we are limited to flat terrain that is navigable by wheeled autonomic vehicles. With this, we can fly down to the bottom of a chasm and take readings down there, where there may be a better chance to find some sign of life (ie an area of Mars that is more well preserved than others).

Re:Interesting

[stratjakt]

This thing could hop around and get a broader view of the planet, compared to the rovers which move what, a meter or two a day?

The terrain might be completely different 100km or so away, but the dirt thats 10 feet from here is probably exactly the same as the dirt you're currently on.

This thing would no doubt have more luck stumbling upon a deposit of water ice or finding bacteria or something of the sort.

The article talks about this being a good way to blast off if you wanted to make a return trip back to earth, which would be good for a potential manned mission, since you'd cut your fuel requirement nearly in half.

Re:Interesting

[zx75]

Remember though, it can analyze ground that we haven't seen close-up at all. It has the ability to travel to rough, or mountainous terrain, or explore into a canyon which are places that our current landers cannot reach. For now we have been limited to flat, rather uninteresting surfaces of mars due to mobility limitations.

Re:Interesting

[drinkypoo]

Besides being able to refuel itself, and cover immense amounts of ground especially as compared to a rover, there's also the aspect that it will pick itself up and shake itself off, thus ensuring that we can avoid any more conversations on slashdot about why the latest vehicle doesn't have wiper blades to brush the dust off the solar panels.

Re:Interesting

[Dorsai65]

It also gives mission control a better idea of what they might want to look at next: during a hop, take a few photos and send them back for review and planning. That and the photos can be stereoscoped to give a better idea of terrain features. No more landing in a crater they can't get out of :-/

Re:Interesting

[radtea]

The advantage this concept has is one of sampling scales. We know very little about Mars in terms of its global minerology, etc. I'd say "geography" and "geology" except some pendant would insist that the correct term is "areology" or "gnu/areology" or something.

In any case, landing in one or two spots tells us about those spots, but we'd really like to know about over overall structure of the planet. On Earth, for example, we have big structures like the Canadian Shield. Landing on one spot and then moving around will tell you that, yep, you got granite over here, too. What we'd like to do is sample on a coarse scale, so we could see that a few 100 km away we've got completely different geology.

That's where the gashopper comes in. It's an extremely clever concept. The Martian atmosphere is mostly CO2, and the cycle of boost, glide, land and recharge could go on for a long time. It's a great way to explore a new planet on a scale that's never been done before.

--Tom

Re:Interesting

[DerekLyons]

With the rovers, we are limited to flat terrain that is navigable by wheeled autonomic vehicles. With this, we can fly down to the bottom of a chasm and take readings down there,

Only so long as the bottom of the chasm has quite a bit of open and reasonably flat terrain, and as long as the chasm is several times wider than the wingspan of the Gashopper. (And the winds are low.)

All this become possible once we develop terrain avoidance software considerably more sophisticated than the current generation, and a computer considerably more powerful, yet lighter and less watt hungry than the current generation...

In short, this is a typical Zubrin proposal. Long on wildly handwaving the advantages (while throwing darts at NASA), and very short on a realistic assesment of the problems and challenges that lay between here and there.

Re:Interesting

[Idarubicin]

I'd say "geography" and "geology" except some pendant would insist that the correct term is "areology" or "gnu/areology" or something.

On behalf of the pedants, I must make two observations. First, it's GNU/areology--the capitals are important.

Second, it's only appropriate to use the GNU prefix if the Magratheans have provided full blueprints for Mars along with the distributed, completed planet. Said plans must be under the GNU GPL (General Planet License).

Glad I could help out.

Re:Interesting

[jafac]

I'd worry about any automated aircraft having to perform risky landings on rough terrain. Response-time between Earth and Mars is sufficiently slow that direct remote-control would be difficult at best. It's the repeated landing that's scary.

Unless this thing has a reusable airbag mechanism.

Re:Interesting

[dj245]

The current rover landing design can't go to many many places because it is far too dangerous to attempt to land on much of the surface of mars with the rolly-airbag ball technique, among other reasons. With this hopper, maybe they could land somewhere near the poles (which are too dangerous/expensive to land near) and then hop there in a series of hops, getting data along the way. Some of the best landing sites for the rolly-airbag landing are also the least interesting. This lets them spread out from desirable rolly-ball landing strips.

Re:Interesting

[astro-g]

and so long ass there is enough sunlight down the bottom of the chasm for it to recharge and fly out again.

Re:Interesting

[Mycroft_VIII]

One thing occures to me, this assumes you do all your data collection while on the ground. I would think there would be some utility to the data collected while flying. You are much closer than an orbital satalite, yet up high enough to observe an area many meters wide and as long as your flight path.

Mycroft

Re:Interesting

[sydres]

because 100km away there may be a basaltic dike intruding in a sedimentary ridge, or there might be a granite outcropping or a sand pile.

Re:Interesting

[douglips]

I'd say "geography" and "geology" except some pendant would insist...

Do you often have problems with your jewelry criticizing your writing? Mine is oddly silent on the issue.

Liquefy CO2? Fly on Mars?

[RealProgrammer]

This guy is Out There.

Or maybe I'm a Luddite. It just seems like an unusual focus for one's life's work.

Oh yeah, and I have to make an obligatory "global warming" mention, just like everyone else.

Re:Liquefy CO2? Fly on Mars?

[Scrameustache]

I have to make an obligatory "global warming" mention, just like everyone else.

Considering that they are going to liquefy the CO2, I think that the fact that Mars is very, very cold is an important factor in their plan.

But I guess you can't say the words "atmospheric CO2" in public without people parroting "global warming". Nevermind the fact that it's extraterrestrial CO2 we're talking about...

Re:Liquefy CO2? Fly on Mars?

[LordWynd]

Well, considering Mars could use a little more CO2 in its atmosphere to prep it for colonization, global warming is a good thing :P

Nose full of "science"

[Jonboy X]

I love that diagram on the website. Future press conference transcript excerpt:

Reporter: "Yes Mr. Zubrin, it's certainly an impressive design. What will be in the nose of the craft?"

Mr. Zurbin: "As you can see from this diagram, the nose of the craft will contain "science". Next question."

Re:Nose full of "science"

[stratjakt]

That's not just a nose, that's a warhead with which to assault martian religious fundamentalists.

"It's a trap! Get those ships away from the Creationism deflector shield!"

Re:Nose full of "science"

[bjelkeman]

I see that you have come across Mr Zubrin IRL too. :) That is just the type of comment I imagine him making.

Liquifying CO2?

[crovira]

CO2 sublimates, doesn't it? Might not make any difference for their application though.

Its a good idea NOT to have to import hydrocarbons as the nearest filling station is back here, far far away. CO2 is pretty plentiful.

The wings holding the solar panels would have to be self-cleaning though.

Re:Liquifying CO2?

[Rosonowski]

It's sublimates, but you can force it to liquefy under pressure. This was actually a point of contention between a friend of mine and his highschool chemistry teacher. They made a bet. He won, then the container exploded and cracked the fume hood. Thankfully, it was due to be replaced in a few weeks anyways.

Re:Liquifying CO2?

[Cid Highwind]

CO2 sublimates, doesn't it?
It does under Earth's amospheric conditions. You can liquefy CO2 by putting it under high pressure (5+ atmospheres, IIRC). When they release the liquid CO2 it'll probably produce gas and small crystals that will sublimate away, like what happens when you discharge a CO2 fire extiguisher on Earth.

It would be neat to watch a rocket powered aircraft that trails dry ice snow instead of smoke and flames...

Re:Liquifying CO2?

[Scrameustache]

The wings holding the solar panels would have to be self-cleaning though.

Well, they'll have pressurized CO2 on hand, they could use some of it to dust off the sloar panels.
If the output of the panels drops below a set threshold, simply blow the dust off with a little bit of the propellant (it must take quite a whole lot more of it to lift the 100lbs craft than it would take to clean its wings).

I'm so sure

[Asshat Canada]

That thing is obviously fake. And look at that guy standing next to it! Photoshop anyone? Nice try editors...What a load of crap.

Re:RTGs?

[Anonymous Coward]

Hope you managed to get your knee out from under your desk before it jerked. Patellar cartilage takes a long time to heal.

You need to learn a little about how RTGs work and how ridiculously clean and safe they actually are.

why even worry?

[Anonymous Coward]

why even worry about the effects on mars? it's an empty cold planet to begin with

Re:why even worry?

[spazoidspam]

Gee, that says a lot about humanities approach to global issues: "It won't affect us, so why not?" Not only are we ruining our OWN planet, but now we're going to ruin another one?

How will this hurt the planet? All they are doing is using solar energy to compress CO2 into liquid form, then heating it back up again to make it rapidly expand back into gas form, giving thrust. This is no different then compressing a bunch of air here on earth and then spraying it back out again. I dont see how this could possibly hurt the enviroment.

Re:why even worry?

[Anonymous Coward]

Why not?

there would still be 7 planets left...

Re:why even worry?

[Valar]

Look, your "logic" has no place here. This is the land of knee jerk, uninformed, karma whoring comments. Please, take your "understanding of concepts" elsewhere.

Re:why even worry?

[krel]

Your objection to "ruining" is undermined when the planet is already ruined. It's a long-held theory that solar wind blew the atmosphere right off the planet, making it totally uninhabitable. As an added bonus, there's no more geothermal energy to gain from the planet and it's too far away from the sun to farm a significant amount of solar energy, so one could say definitively that mars is here and forevermore useless.
On a more general note, it frustrates me whenever I hear people comment that we shouldn't pollute the moon, or throw nuclear waste in to the sun -- as if these places had a delicate ecosystem that some human-defined "pollution" would upset. There is so much room in the universe; in the end, only loony environmentalists care whether a hundred thousand tons of used beanie babies end up "recycled" on earth, or dumped on the moon.

Re:why even worry?

[LWATCDR]

Okay... ummm.... why don't you share your tinfoil hat with Mars to protect it from the space probes?
Sorry but this probe does not damage mars in anyway. it adds no CO2 to the atmosphere. We should not worry about it because there is nothing to worry about.

Re:why even worry?

[Anonymous Coward]

, it frustrates me whenever I hear people comment that we shouldn't pollute the moon, or throw nuclear waste in to the sun -- as if these places had a delicate ecosystem that some human-defined "pollution" would upset.

The thinking for not polluting space is actually based not in environmentalism, but in economics. Launching radioactive waste into space is a non-starter because it is a few million times cheaper to bury it right here on earth.

Anyone who suggests that waste isn't launched into space for any other reason is telling you a tall tale.

Re:why even worry?

[fucksl4shd0t]

As an added bonus, there's no more geothermal energy to gain from the planet and it's too far away from the sun to farm a significant amount of solar energy, so one could say definitively that mars is here and forevermore useless.

Did you forget about strip mining?

And another thing...

[Asshat Canada]

Grasshoppers can't live on Mars! There's no AIR! Read a science book before you make up crap like this.

Re:And another thing...

[Anonymous Coward]

Not much grass, either.

Kinda small

[MyIS]

I know it's OT but it reminded me of an obscure reference...

- ...but Mr Burns...
- *click* Hop in.

Re:Kinda small

[Asshat Canada]

Actually it's a Simpsons reference. It's a popular North American "television series" now in it's third season. It stars the affable Meg Ryan and the butler from "Fresh Prince of Bel Air".

Re:Kinda small

[Anonymous Coward]

It is offtopic. It doesn't have enough detail to make the casual viewer aware of where it's from. And the quote is "Get in", not "hop in"...at least you got the emphasis right, poindexter.

"the gashopper would need

[Sai Babu]

more than a month using its solar cells to refuel and recharge its batteries before it could take off again."

This may well be a feature. Conventional wisdom, when fishing or hunting, is it pays not to move around too much.

Easily tested on earth too.

A really big one might help with moon mining as proposed here. Of course it would literally have to hop as wings are useless on the moon. Low gravity may make the concept practical and gas could be 'waste' from the He3 extraction.

Imagine a whole mining-processing plant hopping about the moon.

Look at the diagram in the article

[stratjakt]

This thing is equipped with a warhead of PURE SCIENCE!

Re:Look at the diagram in the article

[FleaPlus]

Is it a Weapon of Mass Discovery?

Re:Look at the diagram in the article

[Anonymous Coward]

Yes. We likely won't see a war fought with these because of mutually assured instruction.

Grasshoppa!

[Prince Vegeta SSJ4]

Snatch the CO2 from the air, grasshopper!

When you snatch the CO2 from the air, then it will be time for you to leave.

confucious

About Time

[mordors9]

Them martians have been scaring people on this planet for years with their UFOs. Now it's our turn.

Re:About Time

[over_exposed]

yeah, but theirs don't often land somewhere and park it for a month or two at a time... If they did, I'm sure some hick would have submitted his blurry pictures to the National Inquirer already. What we really need to do is modify the Mach 10 scramjet to work in martian atmosphere (don't ask me how, that's up to the NASA brainiacs) and just have it fly laps...

Mad max style vehicles.

[Anonymous Coward]

I will be very pleased to see some mad max style autonomous vehicles roaming on mars.

How would you "fly" it?

[stratjakt]

What kind of response times do you get from mars? I mean, could you interactively fly this thing, or would you just kind of point it and it would end up in some random location, in that general direction?

If the latter, what's the advantage over, say, one of those tumbleweed style bots. What about a tumbleweed with "brakes", that can stop, expore, then curl back up into a ball and move along?

Mars exploration sounds like a candidate for the KISS principle to me.

Re:How would you "fly" it?

[puppet10]

on the order of 1/2 an hour round trip communication times so it would have to mostly be autonomous - say launch to 50 km height, fly that direction at a steady altitude, land, send signal everything went ok, take data, await new instructions.

Re:How would you "fly" it?

[NoImNotNineVolt]

We could put up a constellation of GPS satellites around mars and have point-and-click navigation.

Although I'm sure the cost of a venture like that would be prohibitive for a long time to come, I don't see gashoppers being launched there anytime soon either.

This thing could also yield the benefit of loads of aerial photography to chart the surface with. Pictures from orbit are nice, but aerial photography is nicer still.

Re:How would you "fly" it?

[Scrameustache]

What kind of response times do you get from mars? I mean, could you interactively fly this thing, or would you just kind of point it and it would end up in some random location, in that general direction?

I think there's about a 6 minute delay both ways...

But have you never heard of artificial intelligence, autonomous robots, and autopilot? The thing could be told to go to places selected on topographical maps and fly there autonomously...it's not like there's a lot of air traffic to worry about. There's an annual competition of autonomous flying machines I believe, you might want to google for that.

what's the advantage over, say, one of those tumbleweed style bots.

This one goes where you tell it to go, instead of where the wind takes it.

Re:How would you "fly" it?

[Anonymous Coward]

A GPS system for Mars is already in the works. The main issue is the cost of sending an armada of satellites over there. Thus the plan is to place small generic GPS transponders on basically every Mars probe launched by anybody. Eventually, you'll have a small network of GPS orbiters. NASA is doing exactly this with their planned fleet of Mars Recon Orbiters.

Limitations: as planned, this system won't be AS efficient as what we are used to here because there just won't be as many data sources. But it should do the job well enough and can be expanded if/when the money is there.

Of course, all of this and the "gashopper" are moot if they can get off their butts and clone the overtechnology gravity drive sys

++++ NO CARRIER

It's all about

[Anonymous Coward]

It's all about the statistical analysis. You need a wide array of samples to get an overview of a planet's surface. We just don't have that capability right now (at least to the degree that this would offer).

This will allow us to get a more general picture of specific areas of the planet Mars, rather than the ant-like views that we get from the rovers; that's not to say they aren't important. They are, because they give us very specific information.

It'll be really nice to see this project eventually realized. My question is, how durable can something like the gashopper be? What if it landed funny and broke something?

Re:It's all about

[kaitou]

What if it landed funny and broke something?

We'd point and laugh?

I've got

[Dorsai65]

pressurized gas. Does that mean I can fly around on Mars, too?

THIS IS FINE, JUST MAKE SURE...

[stratjakt]

...You aren't using gas from Uranus.

HAahhahahah get it!?

Oh, fuck off you aren't funny either.

Am I the only one...

[Fizzl]

Who thinks the guy looks like a prototype of a hung-over russian mad scientist?

(No offence to any russian mad scientist having hang-over mind you....)

Christ go outside...

[Anonymous Coward]

you have 4 posts in a 36 post thread..isn't it time to step away from the computer??

Re:Christ go outside...

[stratjakt]

Nope, I have to stay in the office until 6 in case anyone calls for support. I'm the only one here. Noone will call for support because all of our clients have today off.

So I have nothing better to do. Too bad for you, chimpy mcgee.

Re:RTGs?

[MichaelSmith]

I think their concern is that hydrocarbons in the soil will make it difficult to work out what the soil is really made of.

Radioactive metals in the RTG can't confuse chemical analysis, even if they are released during the landing

Re:RTGs?

[Dolphinzilla]

RTG's don't release any chemical compounds, they are only used as heat sources (in this case heating banks of thermocouples to generate electricity) - the fuel pellets are usually bound in plastic to make handling safer.

Wouldn't a prop be more efficient?

[flyingsquid]

Jet propulsion is sort of inefficient as a means of producing thrust- since you accelerate a little bit of mass to a high velocity, that requires more energy than pushing a large mass (as a propeller does) to a lower velocity. So wouldn't using the CO2 to drive a propeller or fan be more efficient (KE = 1/2 MV^2)?

OR, we could reroute the contents of that forward compartment into the engine and create the world's first science-powered vehicle...

Re:Wouldn't a prop be more efficient?

[Anonymous Coward]

The atmosphere of Mars is very thin. Anything involving a propeller or fan is going to be nearly useless.

Re:Wouldn't a prop be more efficient?

[flyingsquid]

Around 1% that of earth's; however, couldn't you just increase the length of the prop blades and/or increase their RPM? Lift is proportional to speed squared, so increasing the RPM tenfold should give you the same amount of thrust as in an Earth atmosphere.

wtf?!

[neko9]

Robert Zubrin's Mars Grasshopper Airplane... i need cofee asap

completely ignore terrain?

[FadedTimes]

The gashopper could land at the edge of a deep chasm, examine the area, jump down to the bottom and get back out again I doubt it could completely ignore terrain. It could land at the edge of a chasm, and then fall into it.

Don't dream of Mars planes yet

[killbill!]

I remember some dude that had created Mars planes on a simulator, using real NASA-supplied data.

His findings: low gravity and ultrathin atmosphere are bitches.

For one, the ultrathin atmosphere (air density 1% of the Earth's) requires huge wings and a very high speed to generate enough lift.

Taking-off and landing are almost impossible. The planes needs a speed of 400 knots to take off. Landing is very... hard because low gravity prevents you from using brakes, and low air density from using reverse thrust.

Of course, the Gashopper isn't supposed to take off or land (it could not anyway). However, it'd still need massive horsepower and huge wings - all of which make it hard to cram the Mars plane into a space probe.
Bottom line: if the plane has been successfully tested on Earth, it is unlikely to work on Mars.

Disclaimer: I am not a Mars aerospace engineer. But that guy's findings were definitely interesting.

Re:Don't dream of Mars planes yet

[killbill!]

Sorry for replying to my own post (I did RTFA... but too fast apparently ;p), but I just noticed the plane is actually supposed to take off and land...

It's even worse than I thought. It just won't fly.

Re:Don't dream of Mars planes yet

[Kiryat Malachi]

Take off and landing are difficult... for HTOL aircraft. This is designed to use VTOL (vertical thrusters) to gain altitude, which won't rely on wings for lift; instead, the thin atmosphere and low gravity are beneficial, as both drag forces and gravity forces are reduced. During takeoff, this thing is basically a rocket, for which thin atmosphere and low gravity are benefits.

Once it hits altitude, it begins to fly; it's going to need a huge wingspan to do that, true, but it can get most of the speed from

Similarly, the landing is vertical, which means that all it needs to do is cancel horizontal speed and then use the vertical thruster as a brake to make a soft landing, roughly the same way the Apollo modules landed on the moon. Stability is the only issue with these, and its a surmountable obstacle.

Bottom line: there's no real reason to believe the takeoff/landing of this is unworkable - Apollo worked the same way. Flight is the only question mark, and we're pretty good at understanding how to make things fly; if they can make it fly in a low-density vacuum chamber on Earth, using helium to simulate the low-gravity condition, it seems likely they can make it fly on Mars.

Disclaimer: I am not a aerospace engineer, though I did take a few aero courses in college.

Re:Don't dream of Mars planes yet

[Scrameustache]

I remember some dude that had created Mars planes on a simulator, using real NASA-supplied data.
His findings: low gravity and ultrathin atmosphere are bitches.

From RTFA, I got the feeling that the plan is for the wings to be mostly controll surfaces, and that the lift would come from the jet of CO2.

Of course, the Gashopper isn't supposed to take off or land

Vertical take off and landing using jets.

I'm sure the good people at NASA's jet propulsion lab are gonna run the numbers better than "some dude" : )

Re:Don't dream of Mars planes yet

[Dorsai65]

huge wings - all of which make it hard to cram the Mars plane into a space probe

Wouldn't be all that though: the first thing that comes to MY mind is an (essentially) inflatable wing - the solar panels can be flexible, and adding some lightweight shape-memory metal (nitinol) reinforcing members might do the trick. "flying" doesn't have to mean "go FAST", just "go". In fact, going slow would have its benefits: more time to detail the terrain thats being flown over.

Re:Don't dream of Mars planes yet

[Anonymous Coward]

Nope, Some Dude is right on target. The grandparent is just misinterpreting the findings.

Re:Don't dream of Mars planes yet

[Anonymous Coward]

Of course Apollo was piloted by humans. Do we have autopilot programs that can land the thing on possibly less than ideal terrain? The lag time between Earth and Mars makes remote control unworkable.

Re:Don't dream of Mars planes yet

[Anonymous Coward]

Yes. We do.

Re:Don't dream of Mars planes yet

[Mycroft_VIII]

Unfortunately slow doesn't work so well on Mars where the atmospheric pressure is 1% that of the Earth's.
The lower the atmospheric pressure the higher your stall speed.

Mycroft

Re:Don't dream of Mars planes yet

[Dorsai65]

Even with an airfoil designed for the combo of pressure and speed? Bummer. Still, the little beastie could "supplement" lift with vertical thrust.

Re:Don't dream of Mars planes yet

[Mycroft_VIII]

More like ONLY with an airfoil designed for the pressure. Someone else in this thread linked to the Xplane site where they tried setting for mars pressure and gravity. One design that actually worked was like a modified u2, HUGE wings, and it still had to go over 500mph or stall. And it needed aircraft carrier type aresters to stop.
Not shure how accurate his simulation is, but Xplane has a fairly high rep for a pc simulator (unluss I'm confusing it with another simulator) so it's not likely off by much.
So yeah, vertical thrust would be needed for a leisurly cruise. Still with an automated system (nice long speed of light delay make realtime remote controll impossible) you just need faster sensors.
Not shure how big an airfoil would have to be to keep a plane aloft at less than 100mph. I imagine somthing with a body size akin to a small go cart might need something the size 747 wings, but made of very light plastics (inflated? lots of room for solar cells though).

Mycroft

Re:Don't dream of Mars planes yet

[Anonymous Coward]

If I understand correctly, lift isnt a factor here. A VTOL craft with static wings, here on earth would be an issue. snapping wings off and all.. This craft is more like a glorified paper airplane. It jumps straight up in the air and then gets a kick from the behind pushing it forward.

So close, and yet...

[Scrameustache]

A really big one might help with moon mining as proposed here. Of course it would literally have to hop as wings are useless on the moon.

The plan is to use stored, compressed atmospheric gasses as propellant for a winged aircraft.

Sit back, and think about this for a second.
Now, tell me again about how this would work on the moon except for the wings.

Re:So close, and yet...

[Sai Babu]

Whoa there Bubba!

I said, "Of course it would literally have to hop as wings are useless on the moon. Low gravity may make the concept practical and gas could be 'waste' from the He3 extraction."

You might also run a fusion reactor on the moon using some of the He3 you've mined and use the heat to vaporize and accelerate other byproducts of mining such as metals.

Links. http://www.space.com/scienceastronomy/helium3_0006 30.html, http://exosci.com/news/129.html (He3 found with concentrations of TiO2), I like the Populrar Science RAIL GUN approach to getting the stuff back to Earth. Another nice thing about proximity of TiO2 and He3 is O2 is handy for miners of the made of meat variety. Perhaps some OPossums or Coons with human like brains (search /. or google for the articles on chimera).

Gotta think outside the bathtub

Re:So close, and yet...

[Scrameustache]

You might also run a fusion reactor on the moon

Whoa there Bubba!

We can't even run those on earth yet.

We are the real Martians

[Maikel_NAI]

As Paul Davies has said: "Mars was ready for life long before Earth. Being a smaller planet it cooled faster. Also, the effect of the asteroid bombardment was less severe. Mars has the volcanoes and water that most astrobiologists believe were needed to incubate life." So if we are here (via panspermia) after been born in Mars, we have to find there the fossils of our ancient relatives.

Physics Buttons

[uberdave]

Gravity's a real bitch.

The physics club at the local university used to sell buttons that read "Friction is a drag", and "Gravity is a downer".

Re:Physics Buttons

[stratjakt]

Yeah, I think I remember holding those guys heads in the toilet while my buddy flushed.

Re:Physics Buttons

[Profane MuthaFucka]

And then the smart guys invented nuclear weapons, and you lived in fear for the rest of your life. Joke's on you. And your kids. And your grand kids. Don't pick on the smart kid. Pick on someone whose capacity for imaginative revenge is limited to mailing dog poop.

Re:Here and now? - Thin martian atmosphere

[UnapprovedThought]

The other side of the coin is that an Earth vehicle can save energy by using lift to take off horizontally, because the atmosphere is thicker. A martian one will probably need to take off vertically, and won't experience lift until it reaches a much higher cruising speed. Once at that speed, it can fly a long way without as much drag, but once you want to land you have to worry about slowing down, so the device had better measure its fuel carefully or have a large wingspan that is retracted just before landing, once again vertically.

Although it sounds less practical than using the same energy for rovers, it might be OK as a proof-of-concept (or proof-of-bad-idea) for a future mission that uses the CO2 to leave orbit on a return trip.

110 LBS

[Anonymous Coward]

The gashopper is 1/3 the weight of the rover. Why is it that they start talking about adding more features, like mini-rovers, to fill in the extra weight? They should just send 3 of them. It will take 30 days for each of them to recharge for flight but you could just offset the take off times by 10 days each. You would have 10 days to study each small area. Or maybe you would stay with one of them that is in an interesting area and only spend a few hours on another. Or split up the group into 3 teams. Whatever. It beats waiting around for the next flight and if one of them crashes into a mountain or something you still have 2 more to work with.

O.T. Mars Society question

[Dr. Cody]

Is this the same group of people who have the laughable reality show on the Discovery Channel? If it is, I would like to point out that these people fund themselves by looking only slightly more embarassing than a furry larping clan on satellite television.

He's not the only one....

[carambola5]

Last Friday (Nov. 19) was a big milestone for many small companies like Robter Zubrin's. This is when NASA announced its 2004 SBIR Phase I awards. And yes, this Gashopper is one of them.

Check them all out at: http://sbir.gsfc.nasa.gov/SBIR/sbir2004/phase1/awa rds/2004topic.html There's really some innovative stuff going on. Also, to the future rocket scientists out there: if you want to work in aerospace, this is an excellent site to find small companies doing NASA subcontracting.

Re:He's not the only one....

[Mycroft_VIII]

Looking down that list I couldn't help but notice one entry*:

Microcide, Inc.
2209 Niagara Drive
Troy , MI 48083-5933
John Lopes ( 248 ) 526 - 9663
04-1-B3.04-8964 JSC
Broad Spectrum Sanitizing Wipes with Food Additives

That's one I'm not shure I want to understand

*emphasis mine

Mycroft

Ode to Robert Zubrin

[Anonymous Coward]

Legendary singer-songwriter Frank Black (Charles Thompson) has written several rock songs about Mars, including this ode to Robert Zubrin. The lyrics say so implicitly, but (as is not uncommon with Thompson's songs) it is also an acrostic poem in which the first letter of each line spells "ROBERT THE CASE FOR MARS ZUBRIN".

cool

[DeathByDuke]

I suppose thats one way of using up all that nasty CO2... then again we wont get to see the first humans take their helmets off and their heads explode like in Total Recall.... damn, theres always a negative to something....

Re:cool

[space_jake]

Damn you Cohegan give those people their air! Admittedly its funnier when said by the Governator....

If it was anyone else but Zubrin...

[Dog's_Breakfast]

If it was anyone else but Zubrin, I might think the idea had merit. Unfortunately, the more ideas I read from this guy, the more convinced I am that he's a nut case. Take a look at this article: http://space.com/news/aps_report_041123.html Zubrin's comments are down at the bottom. In this case, he's insisting that the Hubble Space Telescope was only made possible thanks to the space shuttle (Zubrin is a space shuttle fan - that ought to tell you something). In fact, Hubble was launched on the space shuttle only because NASA was desperately looking for a way to justify the cost of the space shuttle - it would have been much cheaper to send up Hubble on an unmanned rocket. And Hubble was deliberately designed so that it would need constant servicing by the space shuttle, again to justify the space shuttle (and now that the shuttle is grounded, Hubble is falling apart). Zubrin has an agenda. His agenda is not to support good space science, his agenda is to promote Buck Rogers gee-whiz "technology".

Re:If it was anyone else but Zubrin...

[digitalrust]

Not exactly. The shuttle is the only heavy lifter that was powerful enough at the time; maybe it still is. The Hubble was specifically built as large as possible, to go on the largest launcher. It couldn't have gone up on an unmanned rocket, except maybe the Saturn V or Energia... fat chance.

Anecdotally, I recall hearing that the size/weight specs for the Hubble are the same for the last generation KH-?? optical spy satellites; these were also made as large as possible, for the same reason: to make the mirror as large as possible. The last generation radar spy satellites also supposedly looked much like the Magellan radar orbiter that went to Venus.

Re:If it was anyone else but Zubrin...

[Anonymous Coward]

Odd: I get the exact opposite impression from Zubrin's book; he has consistently decried the shuttle program as a huge waste of time and money. He has also described Nasa in short as a goal-less money-eating machine with no worthy purpose; and made rock-solid, scientifically sound proposals (a conclusion I reach by observing that thousands, rather than mere tens or hundreds of other scientists - including other Nasa scientists - agree that they are sound) for unmanned exploration of Mars followed by a humans-to-Mars program, all within my lifetime. I tend to place him in the same category as Burt Rutan, i.e. maverick visionary, rather than 'crank'. Maybe you have your Zubrins confused... try here for better info: http://www.marssociety.org/

where are teh pikmins?

[apostrophesemicolon]

this guy apparently is friends with the pikmin..
white pikmins.. look at the picture

Black Gold

[Anonymous Coward]

They aren't scared of our spacecraft they're afraid Bush will find oil. Martian suicide bombers will make colonizing the planet difficult but I'm sure things will calm down after we hold democratic elections.

Make more, and simpler, probes

[shlashdot]

At this stage of exploration, wouldn't it make more sense to make a bunch of non-mobile, lightweight probes and pepper the planet's surface with them?

Not much solar power in the bottom of a chasm....

[Anonymous Coward]

Not much solar power in the bottom of a chasm....

it's a great idea

[argStyopa]

....my only concern would be the stability and durability of the 'hopper during Mars' famed dust storms. AFAIK the winds there get to be something ferocious, and can last a long, long time. Even at the rarified air pressure of Mars, I'd guess this thing would fly like tumbleweed.

This will not work

[Anonymous Coward]

Ok Mars has a air desnity that is 1/100 of that here on earth. You remember that big wing that that was all electric powers. That flew at 100,000 feet which is kinda the same as on the surface of mars. That is what it takes to fly just on the surface of Mars. Oh yea the gravity is less on Mars, but it is not going to help you to fly at any altitude if there is no air desnity.

Solar power, to battery then to heat? Ok that is hard to do on earth, but this is on mars, futher from the sun, less light less power.

This is just a whole waste of time and money. BUt then again look who is president of the us.

Grasshopper ferries

[Invidious the Evil]

I wonder if it would be possible for larger versions of these to ferry rovers to various locations on the surface. The rover could roam around while the 'hopper compresses. When all is said and done the two dock with each other and set sail for another spot to explore.

I don't understand...

[Brane2]

why is all this complication with CO2 neccessary.

Why not just make a helicopter ?

Atmosphere is thin, but if they can fly conventional wing in it, why not use rotor blades ?

Since they would probably have to be big, they could mount sollar cells right on the blades.
That could take care of the dust buildup too...