NASA Tests New Moon Engine 75
Iddo Genuth writes "Pratt & Whitney Rocketdyne of West Palm Beach, Florida has successfully completed the third round of its Common Extensible Cryogenic Engine (CECE) testing for the National Aeronautics and Space Administration (NASA). CECE is a new deep throttling engine designed to reduce thrust and allow a spacecraft to land gently on the moon, Mars, or some other non-terrestrial surface."
NASA is also set to launch a new satellite on Tuesday — the Orbital Carbon Observatory — that will monitor the level of carbon dioxide in the atmosphere. On the research front, NASA has announced this year's Centennial Challenges. $2 million in prizes are available for a major breakthrough in tether strength (one of the major obstacles for developing a space elevator), and another $2 million is being offered to competitors who are able to beam power to a device climbing a cable at a height of up to one kilometer.
Re:Space elevator power? (Score:3, Informative)
It's the same problem whether you are sending the power for the climber up from below or down from above.
New? They had these in 1936! (Score:3, Informative)
Re:Space elevator power? (Score:4, Informative)
I think one of the silliest notions I ever heard is the idea that we could propel a carriage without a horse, by using explosions from a highly explosive liquid substance. Obviously the first time they try this they are just going to blow the carriage sky heigh. The simple reason this will never work is that they forgot that a carriage has a thing called inertia, and it will quickly buckle under the force of the explosions rather than be propelled down the lane. Even if it could withstand the force of the explosions, could you imagine what kind of jerky ride you would have?
Re:Space elevator power? (Score:3, Informative)
Yes and no. Yes, by itself the moon's slow rotation would call for a really long tether (to match the 27.3 day rotational period, and the counterweight would be too strongly influenced by Earth's gravity. I haven't done the calculations, but it wouldn't surprise me if the tether would have to pass through the Earth itself.
However, there is another space elevator design that will work. Between the Earth and the Moon lies the first Lagrange point of the Earth-Moon system (EML1). It is essentially the point where the gravitational pull from the Earth matches the gravitational pull of the Moon. Anything on the Earthward side of the EML1 gets pulled to the Earth, and anything on the Moonward side of EML1 gets pulled to the Moon. So, basically what you do is hang the counterweight on the Earthward side of EML1, and run the tether to the Moon. The counterweight is going to want to fall to Earth, but it will not be able to because it is tethered to the Moon.
Apparently we have sufficiently strong materials right now to be able to create such a tether. There are still engineering difficulties (such as getting a 56,000+ km length of kevlar rope strung out from the moon to the counterweight) but a lunar tether lies within our current technological capabilites