[Spaceships] Getting A Few Thousand Extra MPS

[Varyon]

Originally Posted by Aldric

I don't understand what the problems would be (according to the rules in Spaceships) with building say an SM+10 fusion drive ship, grabbing an ice rock 10x the size of the ship and heading off with about 4k mps to spare.
Acceleration at the start of the journey might be quite bad (1/11 of what the engines usually provide) but it would improve over time.
If a rock/asteroid is too unstable and possibly not pure enough, you can still build a "ship" made of 20 fuel tanks for about 600M and push that.

If the ice rock were somehow pure hydrogen, that's a 90.9% mass fraction. That's the same as having 18 fuel tanks, for x2.5 to delta-v per tank. At 60 mps per tank, that's a total of 2700 mps delta-v. Without a ramscoop, that means a travel speed of 1350 mps, and ignoring time to accelerate and decelerate, a travel time of 533 years and 4 months. And your rock is unlikely to be pure hydrogen - at best you're looking at more-or-less pure water, which has 3x the acceleration but 1/3rd the delta-v, for a total of 900 mps - at 450 mps travel speed, that's 1,600 years.

You're gonna need a bigger rock...