Thread:20100vincent/@comment-6752454-20141120165604

I would just just like to summarize a few points on why your "space cannon" can't work:

1. Friction: Escade velocity is 6.6km/s or 23760km/h. That can't change. But air resistance rises exponentially with velocity, and at surface level that is approximately Mach 20. At that speed you will quickly lose most of it long before you reach space. And that assumes the turbulence doesn't throw you off course. Not to mention the massive sonic boom.

2. Explosion : To accelerate just a 1 ton satellite to escape velocity takes the equivalent of 10 tonnes of TNT. This means trying to a make extremely delicate systems endure full scale explosives. And while you may suggest generating the necessary force with nuclear reactions, I don't feel like getting into the numerous flaws of launching a satellite by detonating a nuke.

3. Acceleration: If we once again assume a generous launch velocity of 6.6km/s, with the cannon takimg 1s to fire, then you push your satellite through nearly 700 G of acceleration. For any kind of escape velocity you'd hit it in the thousands of G, and the friction alone may generate several G after launch. Needless to say this makes "suicidal" an understatement for any kind of manned usage of this.

4. Control: Assuming you even make it to space (hoping that drag doesn't send you off course, and that your ships hasn't been reduced to useless junk by the acceleration) if you intend to stick your satellite into any kind of useful orbit, and maintain it against atmospheric drag long-term, you'll need thrusters. I'm not going to bother explaining why it's a bad idea to expose rocket fuel to extreme accelerations and nuclear explosions. 