Turtle on 28/9/2010 at 18:58
I think I got my virginity back just reading those last few posts.
Kolya on 28/9/2010 at 20:54
Quote Posted by Vivian
Seeing as the hoop is vertical, not horizontal, the helicopter is flying through the hoop.
The point is that the helicopter might make that flight anyway while the hoop is deliberately thrown in its way, a rather simple artistic trick. In which case the hoop could be said to fall around the flying heli, vertical or not.
catbarf on 28/9/2010 at 23:33
Quote Posted by Vivian
Unless your spacecraft weighs less than half a tonne, even 5000N is useless for Earth-to-orbit. Space Shuttle engine, which is I guess fairly representative, does something like 2 million newtons.
As I said:
Quote:
No, it can not simply turn on the engine and fly to space. But the high thrust mode does provide enough thrust for suborbital maneuvering with very reasonable reaction mass consumption, which current chemical rockets are pathetically bad at
Using an ion drive, for example, would not have enough thrust for orbital maneuvering. So you'd need three stages- first the booster rockets, then a conventional chemical engine, then the ion drive. That's horribly inefficient. With a VASIMR, all you need are the booster rockets. You cut the engine mass in half.
Vivian on 29/9/2010 at 01:14
Quote Posted by catbarf
As I said:
The VASIMR is the first method of spacecraft propulsion besides the Orion drive (which has some big problems, namely that it requires you to detonate a nuclear bomb) that is feasible for both Earth-to-orbit and orbit-to-orbit transitions
Yeah, everything else sounds awesome. That bits wrong though. How much power does a decent size solar cell array generate in space these days anyway? Any chance the vasimir could propel (
http://en.wikipedia.org/wiki/Self-replicating_spacecraft) von Neumann probes?
catbarf on 29/9/2010 at 01:57
Suppose I should have clarified that I meant LEO-to-proper-orbit. I don't see anything short of a nuclear thermal rocket replacing chemical rockets for liftoff anytime soon.
And the VASIMR could very well run off of solar panels- it only needs a few kilowatts.
