3 ms·
It would be interesting to see a quantitative head-to-head comparison, but my guess would be that once you have the technology to retrieve first-stage rocket en
by maxander 11y ago
It would be interesting to see a quantitative head-to-head comparison, but my guess would be that once you have the technology to retrieve first-stage rocket engines after launch space-guns aren't economical- the fuel used lifting the engine itself may be expensive, but the energy losses from hitting sea-level atmosphere at ~8km/h would have to be astronomical.
...As it were.
- gvb 11y agoSpaceX appears to be competitive even without reusing the first stage: At its 2013 launch price and at full LEO payload capacity, the Falcon 9 v1.1 cost $1,864 per pound ($4,109/kg). Ref: https://en.wikipedia.org/wiki/Falcon_9#Launch_prices https://en.wikipedia.org/wiki/Falcon_9#Launch_prices From TFA: The cost was roughly $1,727 per kilogram, adjusting for inflation. By comparison, Nasa estimates that it costs $22,000 per kilogram to launch a modern satellite into orbit using conventional rockets.
- mrfusion 11y agoI disagree. With a rocket you have to lift all your fuel. With a space gun the fuel stays on earth and only the payload goes to space. Look up the rocket equation to see what a huge difference this makes.
- maxander 11y agoDoes it, though? I mean, I've played KSP, I know the rocket equation. But with a space gun, your vehicle only winds up moving as fast as the propellant pushing it out- so that mass of fuel (more explosive than fuel, I guess) still has to be accelerated to near-orbital speeds in order for the gun to work.
- pizza 11y agoWhat about a railgun or some similar accelerator prior to the first stage?
- vlehto 11y agoRocket engines are light. But rockets need lots of fuel. The problem is lifting all the fuel.