Quote pyramid deconstructed.
you do have to use energy to get the spin, but it's much less than the energy needed to decelerate to land on a planet safely.
Not what I was asking, but I doubt this. How much energy was spent by Neil Armstrong and Buzz Aldren when they fell into the ocean?
You have to use energy to keep it spinning, but the modifications are insignificant in comparison to those of getting resources from Mars. Probably the energy for one mission to get resources from Mars would use more energy than correcting the spin for the whole lifespan of the station.
Yeah, it takes less energy to keep a space station spinning than it takes to perform a mission to gather resources from Mars, but it also takes more resources to make a space station than a spacecraft capable of reaching Mars. That comparison is much more relevant than yours, because A. the space station and space ship are being used for roughly the same purpose, B. have more technical similarities, and C. you need to go to planets or wherever for resources anyways, because steel doesn't grow on vacuum.
Why would a ship have to dock on the outside. put the dock in the middle and use an elevator or whatnot to get to the edges.
The middle spins, too. Unless you want to make the ship even more complicated than it needs to be...
...I don't think that answered my question.
Yes, you'd get the energy from the reactors; no, it wouldn't be infinite. Solar energy might be close but won't be infinite.
Your example has you expending energy to spin. Why wouldn't a spacecraft need a (probably small) amount of energy spent to keep the centrifugal force up?
Once spun, the kinetic energy of every point of the rotating object remain constant(as in Newton's 2nd law for rotational motion). Barring outside influences, or the inhabitants' conscious cooperation to change it, the station will spin indefinitely with constant angular velocity.
Ah. The "spinning=gravity=acceleration=not allowed for free with thermodynamics" is what was tripping me up.
1. It's not going to solve the problem by spinning the spacecraft as it docks; it'll need to actually have a curved trajectory matching that of the outside of the ship. That's kinda hard without gravity (nil between such small objects) or tethers or something...
Here's a famous scene from 2001: A Space Odyssey showcasing how it works.
http://www.youtube.com/watch?v=q3oHmVhviO8
Any good physics-based space game simulates this element of space travel as well. Try Elite 2 & 3, Orbiter, Terminus, Babylon5:IFH.
Ah, I see now. Well, see below.
GWG, am I correct in assuming you want the docking port to be mounted on an equatorial plane of a body rotating to mimic gravity? Docking at the pole/rotation axis of a rotating body would be much simpler.
It's still spinning, just less. Which means there's the same problem, just less. Or maybe more, since the spin is more tightly curved.
We've been looking at the negatives of stations, but what about negatives of planetary ones.
Gravity + meteor - atmosphere = shooting range.
Oh, right, I forgot how there's no way to protect from meteors and how they're so common that Neil Armstrong said, "That's one small step for man an--CRCKzzzzzzz..." Oh, wait, he didn't.
Yes, maintenance would be needed. Guess what? That's true everywhere. Easy access to various resources should counteract that, especially since you would actually have the materials to make repairs. Oh, and by the way? There's meteors in space too.
Also, have you noticed that most of my suggestions for, say, Lunar bases have most of the bases underground? If a meteor can penetrate dozens of feet of solid rock, maybe hundreds, it could probably hit your little space station too.
