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Alternative Orion Missions Proposed
skywatcher2501 writes "Lockheed Martin, the company producing NASA's new Orion spacecraft,
published three videos (news article in German) showing alternative Orion missions. Great efforts are made to show Orion's flexibility as a space transportation system beyond the goals of the Constellation program." The three videos, respectively, illustrate ISS missions with cargo in low-Earth orbit; autonomous use of the service module; and maintenance missions from low-earth orbit to geosynchronous orbit.
http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)
Of course this type of nuclear propulsion is just made of lulz, NERVA's are the way to go.
Funny you should mention this. Per this source, American manned space flight is in serious doubt. If true, I'd say even unmanned American space flight is in jeopardy as well. Why buy space toys when you can buy votes?
Understanding the scope of the problem is the first step on the path to true panic.
Orion [the original project] was never designed to reach orbit from Earth but in fact was only meant for space travel owing to its use of nuclear weapons being detonated behind the ship sequentially.
Sigs are too short to say anything truly profound so read the above post instead.
The Orion spacecraft is not the problem with the current NASA Constellation program. The Ares I launch vehicle is. It does not have the lifting capability, among other problems, to meet the goals of the program so they keep cutting back on the capability of the one thing that its supposed to lift to orbit, the Orion crew capsule.
Sig this!
I am a fan of commercial space as much as the next guy, but they have yet to put a single person in orbit, yet alone get to the moon. Even the Dragon spacecraft cannot handle a re-entry from the moon.
Project Orion was certainly designed for planetary launch. They even did an analysis of how many people it would kill per launch due to fallout.
"It is possible to commit no errors and still lose. That is not a weakness. That is life." -Peak Performance
There was and is a good reason to keep manned spacecraft in LEO. Radiation. Geosynchronous satellites are outside the protection of the Van Allen radiation belts, and any astronauts traveling outside that protection are subject to high doses of pretty nasty radiation under normal circumstances, and outright lethal doses when solar storms occur.
We still don't have a good solution to the radiation problem, which is one of the major obstacles to practical moon bases and Mars missions. Leave the satellite maintenance to robots. How about a robotic craft that could grab a satellite and ferry it to the ISS for repair? Now THAT'S a worthwhile mission...
Its a little more complicated than that. The reason you use a lot more fuel to get out of the atmosphere than you use once you make orbit, even on interplanetary missions, is that you've got to carry all that fuel with you out of the atmosphere.
Spacecraft sizing is like a Russian nesting doll. If you required a 4:1 ratio of propellant to spacecraft mass to get to the moon, and you were able to reduce it to 2:1 propellant ratio, you could get away with about half the launch vehicle because you don't need to launch all that propellant. The equations defining this (Tsiolkovsky's rocket equation) are all exponential with Delta-V.
Now as you can imagine, doing a return trip is even harder... imagine a Mars sample return mission. You have to have enough fuel in Martian orbit to get your sample and re-entry vehicle from there back to Earth. You have to have enough fuel on the surface to get that fuel and the sample into orbit. This means you have to send all of that fuel to the surface in the first place (requiring more for the entry burns), and of course this defines the amount of fuel required to leave Earth and get to Mars, which in turn defines the size of the initial launch vehicle. Minimizing one of the steps is enough to fit the mission onto a much smaller LV. This is why concepts like using ion engines, leaving return vehicles in orbit (like in Apollo), and extracting fuel from the target (ISRU) are so important, even though the amounts of propellant are small compared to the initial LV.
3 There have been a few sucessful commercial launches
No, there's a plenty of commercial satelittes launches every single year. ULA, EADS Astrium, Orbital to name a few.
I don't know where to get statistics for this but a commercial launch is something very common place.
English is not my first language. Corrections and suggestions are welcome.
according to this site. you're correct. I quote:
"In the early 1960s, Freeman Dyson estimated that each launch from Earth would cause, on average, 10 fatal human cancers among the population of the entire planet (some people argue that these figures may be an over estimate because of the particular mathematical model used). "
From what I recall from the Project Orion book, they managed to get the estimated death down a bit, but still. A solution would be to only use the orion drive while in space, and only when outside earth's van allen belt as the magnetic field would drag some of the fallout back to earth.
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