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Space Tourist Trips To the Moon May Fly On Recycled Spaceships
thomst writes "Rob Coppinger of Space.com reports that UK-based private company Excalibur Almaz plans to offer commercial lunar-orbital tourist missions based on recycled Soviet-era Soyuz vehicle and Salyut space stations, using Hall Effect thrusters to power the ensemble from Earth orbit to the Moon and back. The company estimates ticket prices at $150 million per seat (with a 50% profit margin), and expects to sell about 30 of them. Excalibur Almaz has other big plans, too, including ISS crew transport, Lagrange Point scientific missions, and Lunar surface payload deliveries. It expects to launch its first tourist trip to the Moon in 2014."
Several articles on /. along these lines recently. Humble beginnings from actual private space enterprise closely followed by science fiction from space charletons.
Who cares about sustainability with business? Lots of businesses have no such need; they get in, make a bunch of money, and that's the end of it; as long as the owners are able to walk away with a pile of cash, that's good enough for them.
Not all businesses need to continue to grow without end. That's mainly a requirement of publicly-traded companies because shareholders expect it, but private businesses operate very differently.
If these business owners think they can get a few dozen rich people to pony up $150M apiece for Moon tickets, at a claimed 50% profit margin thanks to recycled Soviet hardware, that's a nice hunk of profit to walk away with after 5 years or so.
When you're 60+ years old and have tons of money, but not that much time left on the Earth, you don't really worry so much about the risk of such ventures. Just being able to go to the Moon is a once-in-a-lifetime thing and only a very tiny number of people have even done it so far. Just like it wouldn't be that hard to find people willing to take a one-way trip to Mars despite the extreme risk there, I don't think they'll have much trouble finding people willing to take the risk of traveling to the Moon in a recycled Soviet capsule (esp. if they can do it once successfully to prove they can do it). The question is if they'll find enough people with the required funds willing to do it; however, the Russians didn't have that much trouble finding rich people willing to spend $20M on a ticket to LEO, so it's possible.
Hall effect thrusters are NOT high thrust devices. He's not talking three days to Luna, more like three MONTHS.
Each way.
Somehow, I'm not seeing this as terribly practical.
"I do not agree with what you say, but I will defend to the death your right to say it"
For those unfamiliar with the tradeoffs: Hall effect thrusters make fairly efficient use of the reaction mass - about 2000s, compared to ~250 for solid rockets or ~300-400 for liquid rockets. That means a considerable increase in your delta-v - since you only need 10-20% as much reaction mass for the same impulse, you get 5-10x more delta-v. Great, right?
The trouble is that you need a power source. Liquid fuel rockets just burn the propellant. Hall effect thrusters (and other ion thrusters) need a power source in addition to the propellant.
This is a great tradeoff for stationkeeping on satellites - you only need tiny amounts of thrust, so you can easily generate enough power using solar cells or a RTG. Thus the very efficient use of reaction mass means a much longer useful life, or more useful payload in your satellite for a given launch mass, etc. It's just plain more efficient.
But this isn't like that. They seem to want to use them to perform the Hohmann tranfer. That means having a very high thrust for a short duration - not just because you want to get there more quickly, but because it's much more efficient than a long continuous burn.
They're talking about 100KW. That seems low. Ballpark 5000 newtons of thrust... Compare to the Apollo command/service module at ~90,000 newtons. Thus they'll need a fairly long burn at that power. How the heck are they generate that kind of power for a long duration?