New NASA rocket fuel 'could be made on Moon, Mars'
Exploding toothpaste to bring astronauts home
NASA, in a joint venture with US air force boffins, has tested a new kind of rocket fuel which "has the consistency of toothpaste" and could potentially be manufactured off-planet in remote space outposts. Its inventors say it is also less environmentally damaging than some current rocket fuels when used within Earth's atmosphere, and could be more powerful too.
The new wonder-paste is composed of aluminium powder and ordinary water ice, and is known as Al-ice or ALICE. The clever bit is that the aluminium powder is extremely fine - "nanoscale" fine - giving it much greater surface area and letting it react with the water much more vigorously. The vid above, courtesy of Purdue university, explains in more detail.
An ALICE-fuelled rocket was flight tested in Indiana earlier this month, apparently, reaching thrust of 650 pounds as it soared into the sky.
"ALICE can be improved with the addition of oxidizers and become a potential solid rocket propellant on Earth," says Dr Steven F Son of Purdue university. "Theoretically, ALICE can be manufactured in distant places like the moon or Mars, instead of being transported to distant locations at high cost."
The jury's still out on whether there are useful amounts of water ice on the Moon, but there's known to be some on Mars. Being able to make rocket fuel on either body would be good news for prospective interplanetary expedition planners, as lugging fuel out from Earth for the return journey takes up a distressing amount of the outbound spacecraft's payload.
As for environmental friendliness here on Earth, it would be hard to be a lot friendlier than the commonly-used liquid hydrogen-oxygen rockets in common use - their exhaust is made up of water vapour. But the new ALICE tech could well be nicer than some present-day solid fuels. ®
Why don't we visit the oceans?
We know less about the earth's oceans than we know about the moon/mars. It doesn't need all sorts of boffinry and is more meaningful.
@ Chris McFaul
Depends on the liquid fuel combo used. Some rocket engines burn pure liquid hydrogen and liquid oxygen. (no additives needed) Some burn rocket grade kerosene (RP-1) and liquid oxygen. Some burn hydrazine and nitrogen tetroxide, which is nasty stuff. The later, and other hypergolic fuels like them, are probably the one you're thinking of when you say "extremely toxic" and are often used in upper stages or thrusters. This isn't by any means an exclusive list of fuel combinations. You might find one or more of these combined together in separate stages on one vehiclet.
The correct term for Helium would be a consumable. It does not burn but probably would escape the Earth.
"Rockoons" (rocket-ballons) have been proposed regularly since the 1950s. Some have flown.
The problem is this.
Balloon carries big rocket up to altitude (this allowas a *very* big expansion nozzle on the engines which improve Isp quite a lot. At sea level the final pressure inside the nozzle would be so low it would trigger massive shaking and destroy itself)
Balloon looses huge portion of mass balencing the lift gas.
Balloon goes into sudden fast ascent
Skin tension rises to bursting levels
Gas vents fast enough to stop it and balloon goes into dive.
Gas does not vent fast enough and ballon bursts.
If it were hydrogen it could be burnt off (and hydrogen is cheap and used in high altitude weather ballons regularly)
Helium is not that rare. Most Helium in the US comes from collecting it at oil wellheads in Texas where it exists with the oil in reservoir strata. This was the supply Germany wanted to use to gas the Hindenburg which the US refused to supply and which caused the switch to Hydrogen.
On a general point. Water is quite rare and should be conserved. It contains hydrogen, which on planets (which are what people tend to prefer not interplanatary or interstellar space) people might live on is rare. Hydrogen is akward to store in pure form and difficult to seperate in compounds (unless you have a compact nuclear reactor handy). Probably best avoided as a rocket fuel.