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The moon would be acceptable and Mars is simply the next big thing. Esp. the moon because you can use a cannon to launch spacecraft so you don't need to use fu
by zaarn 8y ago
The moon would be acceptable and Mars is simply the next big thing.
Esp. the moon because you can use a cannon to launch spacecraft so you don't need to use fuel on it (if you'd do it with a magnetic cannon you could do it entirely with solar arrays).
- mirekrusin 8y agoEscape velocity is more than 2km/s, roughly the speed of bullet, that's a bit too much to "launch spacecraft" or am I missing something? ps. it's actually interesting concept, you could have something similar to medieval catapult on the Moon and throw rocks on Earth which would be equivalent to nuclear explosions, no?
- steve_musk 8y agoNo/little air resistance and plenty of space mean that you could accelerate the spacecraft over a longer period of time
- mirimir 8y agoSee Heinlein's The Moon Is a Harsh Mistress.
- RegBarclay 8y agoRIP NORAD
- wongarsu 8y agoAccelerating from 0 to 2km/s at 3g (suitable for humans) takes about 60 seconds, and a barrel that's about 70km long (40 miles). That's no easy feat, but certainly achievable. You can get around the barrel length by building a circular barrel (with it's own set of problems). Just launching cargo is a lot easier, we already know how to accelerate things to the speed of a bullet in a variety of ways. Scaling up a railgun to handle heavier bullets is comparatively easy.
- pjc50 8y agoA single long metal rail would suffice, with a maglev acceleration system. Lack of atmosphere makes it easier too. Could probably manage up to 10g with a bit of scaling at the ends, although might be bad for people who'd been on the moon for a while. Cargo could be made to go much, much faster.
- VikingCoder 8y agoFor payloads, I suspect a Slingatron on the moon would work well... https://www.kickstarter.com/projects/391496725/the-slingatron-building-a-railroad-to-space https://www.kickstarter.com/projects/391496725/the-slingatro...
- gandutraveler 8y agoShouldn't the escape velocity be way less when firing from moon to earth ?
- zaarn 8y agoFor non-alive payloads you can accelerate at >10g and get a comfortably short rail to fire the bullet from. For alive payloads, the rail becomes longer. The advantage is that on the moon the low gravity and no atmosphere make megastructures like this easier to build. Energy is also no concern either, you have pure unfiltered sunlight for about 15 days each month on each side of the moon.