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Chinese astronauts make rocket fuel and oxygen in space

(www.livescience.com)
298 points Teever | 3 comments | 24 Aug 25 17:54 UTC | HN request time: 0.399s | source
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habibur ◴[26 Aug 25 22:08 UTC] No.45032963[source]▶
This won't enable perpetual space travel in case anyone thought so.

Rockets need to eject particles to generate force. And to eject 1 kg of fuel, its photo synthesis system has to lose 1 km of mass in one way or another.

The solution is to find a way to generate thrust without rocket fuel ejection.

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Buttons840 ◴[26 Aug 25 22:22 UTC] No.45033094[source]▶
Can we "swim" through space? Collect particles from space, add energy, expell them backwards to generate a net thrust.
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aspbee555 ◴[26 Aug 25 22:25 UTC] No.45033121[source]▶
no particles needed, we already have ion drive, just need electricity
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1. Taniwha ◴[26 Aug 25 22:28 UTC] No.45033141[source]▶
Ions are atoms ..... tiny particles
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2. grues-dinner ◴[26 Aug 25 23:13 UTC] No.45033491[source]▶
Quite big tiny particles in this application: Xenon is a fairly hefty atomic number of 54 - exactly double iron.

And you need quite a bit of it: even fairly small spacecraft like probes can have nearly a tonne of the stuff. Which, considering there's only 30-40ish tonnes extracted per year at a cost of about 1.5ish dollars per gram is quite a bit!

3. lmm ◴[27 Aug 25 02:14 UTC] No.45034731[source]▶
Ions are small enough that you can bring enough for a whole trip pretty easily. Yes they're still consumable, but you need a tiny fraction of the reaction mass you need with a conventional rocket.