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.

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).

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: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.

Look at the diagram in the article

[stratjakt]

This thing is equipped with a warhead of PURE SCIENCE!

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.

About Time

[mordors9]

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

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...