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Inflatable Spaceship Ready for Test
colonist writes "Nature reports that an inflatable re-entry vehicle could one day carry astronauts or robots to the surface of Earth or Mars. The heat shield (that can withstand 900 C) and the parachute are inflatable. The advantage of inflatable structures is weight: a 130 kg vehicle can carry about 200 kg of cargo back from the space station. The vehicle is made by Return and Rescue Space Systems."
It's for re-entry, not for general flight in space.
It's the heat shields that are inflatable, and they are armored - e.g. not the same material as your pool floats...
feh. stuff.
The surface is made from a tough, flexible polymer coated with a paint that can withstand temperatures of around 900 C. The exact composition of the paint is a closely guarded secret, says Joachim Thäter, an engineer at RRSS.
I was more amazed that it can withstand the heat of re-entry when you consider that the ceramic tiles on the shuttle glow red from the friction of the atmosphere.
Probably there is far more detail that clears these things up but I doubt the average non slashdot reader is all that picky about the details.
Cheers,
Erick
http://www.busyweather.com/
I believe they used parachutes to help land the rovers, so they do work. I think the atmosphere is thin, but with a big enough chute it will help to slow it down.
I was more amazed that it can withstand the heat of re-entry when you consider that the ceramic tiles on the shuttle glow red from the friction of the atmosphere.
Mars' atmosphere is much thinner than Earth's so it wouldn't generate nearly as much heat.
JacquesItch
Look, unless you happen to be a rocket scientist, perhaps you should leave the heavy thinking to the NASA engineers. (I happen to be one, but think of me as a wanna-be myself, as I am transferring over to the Electric space propulsion division soon)
Anyway, I would agree to your comment, that yes, due to Mars gravity, it would be hard(er), well harder 40 YEARS AGO. Technology and efficiency have taken great strides these past 40 years, and we feel confident in our ability to make a rocket that does what its supposed to do.
I can tell you, that Mars manned missions have been fully detailed with many many different mission paths that could be taken. For instance, using Ion propulsion and launching from the International space station or the moon are one of the many possibilities that have already been detailed by many scientists and engineers.
Give NASA a little faith; you don't need to back seat drive them like some little ol' lady.
//Information does not want to be free; it wants to breed.
Yes, however, there are two factors that make this a far easier technical challenge:
A) An inflatable structure like this has a *much* larger surface area. The goal here is not to "soak up" the heat, but to radiate it away. This is largely surface area limited. This allows it to keep the temperature down.
B) The very large cross-sectional area of an inflatable reentry system allows the craft to begin to slow down from air resistance at higher altitudes. Not only does this mean that the craft doesn't need as much fuel for reentry, but it allows for a steadier velocity reduction profile.
C) Lower temperatures of reentry make *huge* differences. Look at the tensile strength of aluminum alloys at different temperatures, for example, here's some data on Aluminum AA 1100 O (a cheap aluminum):
Temperature (K) Tensile Strength (MPa)
53, 172
183, 103
242, 96
328, 90
386, 69
441, 55
503, 41
566, 28
628, 20
691, 14
Here's data from a good aluminum alloy - AA 7178 T76 T7651:
53, 730
183, 634
242, 606
328, 572
386, 475
441, 214
503, 103
566, 76
628, 58
691, 45
Now, we're not dealing with an aluminum parachute or anything here - aluminum is just something that I happened to have data for offhand. However, you often see tensile strength fall off like this with most materials. Temperature is a *very* important factor.
I'm you from the future! We have to finish our time machine before the Angels of Destruction find the portal!
Dude...it's not the foam insulation at several hundred miles per hour that's the problem. It's the pound-and-a-half of foam plus ice that's the trouble.
The kinetic energy of 750 g of foam at 240 meters per second is about 22 kJ. That's about the energy delivered in ten high-powered rifle shots , or in the neighbourhood of a hundred rounds from a moderately-sized handgun. The leading edge of the Shuttle wing that took the collision is already one of the most heavily reinforced parts of the Shuttle, and it's made with a carbon-fibre composite material--not the brittle tiles. Even so, the foam was a lot more abuse than we could expect it to stand.
When the oxygen tank blew in the Apollo 13 service module, there was a great deal of concern at NASA about it because they were afraid that it might have damaged their heat shield. In that case, they tried the reentry anyway, because (as with Columbia) there wouldn't be any good way to effect rapairs or launch a rescue. It turned out all right, but there were a lot of nervous engineers. I expect that faced with a couple pounds of material at five hundred miles per hour, the Apollo heat shield wouldn't have made it either.
~Idarubicin