Tuesday, July 11, 2023

Fusion rocket being planned in the UK



Here's an idea that I once discussed many years ago with a fellow who identified himself on Twitter as Quantum G.

The idea was that you do not need a net energy production from fusion in order to use it as a propulsive device. The fusion reaction does occur. Modern devices ARE capable of producing fusion reactions. But they are NOT capable of getting positive net energy out of them.

Therefore, an onboard device that can generate the necessary energy to produce the fusion reactions will get you the reaction mass that can propel a ship. In this case, the proposition is to use a fission reactor to produce the energy that drives the fusion reactions.

The result would be an ISP of 10-15 times the best devices available today.

The Angry Astronaut did not specify the downsides enough. The trouble with these kinds of devices is 1) the high energy requirements will produce a lot of heat. How to cool it down? and 2) What kind of thrust can this device produce? Ion engines do not produce much thrust. You would need to produce a lot of reactions in order to get a lot of reaction mass.

The VASIMIR proposed spacecraft can also produce a high ISP, but it doesn't have an energy device either.

ISP is like MPG for automobiles. The higher the ISP, the further you can go on a tank of fuel. The ISP mentioned here could be around 30-45k. That's several orders of magnitude better than chemical engines. But there's no mention of thrust capacity on this video. Nor heat management.

An interesting video anyway... Enjoy



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