[Spaceships] Million Merchant Marathon

[scc]

Originally Posted by sir_pudding

I find the combination of worrying about low-dv transfer orbits with large scale planetary engineering to be incongruous. If the former is a concern you really probably don't have the technology or the resources to do the latter. If you can confidently spin up 5x10^24 kg of Venus by 500 m/s, then you should be able to give a infintesimal fraction of that mass a similar delta-v.

I'm not planning on spinning Venus up. At most I'd go for what is necessary to get the atmosphere off, which imparts just over 3 kph at the equator and is like a 50% increase.

Originally Posted by Fred Brackin

You don't uee transfer orbits for mass driver payloads. You're not using limited reaction mass and you have no manned crews whose time in space you're trying to limit. You fire off payloads continuously and they get where they're going when they get there.

Even if you are using mag sails they're not well suited for transfer orbits. Mag sails don't have limited Delta-V to be conserved by using a Hohman orbit. They make thrust (in small amounts) on a continuoius basis without any energy expenditure after you deploy the sail.

This is most of why I originally thought you were using rocket ships. Rocket ships need Hohman orbits.

Originally Posted by Anthony

You might. It depends how much velocity you want to build your mass driver for. I suspect it's easiest to have a modest size window.

Originally Posted by Fred Brackin

I suspect that for brobdinagian purposes like terraforming you want to keep all of your terraforming machinery working as close to 24/7 as possible.

So just firing off tanks full of gas or liquid has some problems. #1 is controlling their entry into Cis-Lunar space. Keep in mind the the original idea of using Mass Drivers in this sort of manner was for getting Luna material on the Moon, the catcher ships where designed to shred the blocks of pressed together material, I'm going to need to put them in boxes with some sort of maintenance equipment, which I'll want to reuse. #2 is stopping them from hitting each other mid flight. Items launched during the two week least time interval don't all take the same time to travel, those launched first arrive last and those launched last arrive first, so there's a nasty crossover problem, and the moment you start saying it's firing all year despite the rate of launch being steady the rate of arrival will not be.