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#26 2026-11-02 09:13:13
- Calliban
- Member
- From: Northern England, UK
- Registered: 2019-08-18
- Posts: 4,462
Re: Large Ship Atomic Propulsion
The shielding problem can be mitigated (partially) by distance. Unshielded dose follows the inverse square law. The USS Discovery in 2001: A Space Odyssey captured that quite accurately. The propulsion section was seperated from the habitation section by a long pylon. Waste heat radiators are a more difficult problem. One way of making them smaller is to dump heat at higher temperatures. The heat flux from a radiator scales with the fourth power of temperature. But that causes problems as well if the heat produced by a reactor is needed to run some sort of heat engine. Dumping heat at higher temperature then negatively impacts efficiency.
I cannot really comment on your 10B-P fusion engine design.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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#27 Today 13:31:27
- Void
- Member
- Registered: 2011-12-29
- Posts: 10,047
Re: Large Ship Atomic Propulsion
I might be intruding in ignorance, not sure why radiators are needed, if it is nuclear thermal. Yes you do need if Nuclear-Electric>Plasma.
The Pylon idea is interesting. What about thethers?
If you had a slow spinning spider web of Carbon-Unicorn materials, then you could put nuclear, cargo, and habitation structure at a distance very favorable to radiation protection.
If Nuclear Thermal, then you have to bring Hydrogen with you to Mars in order to get your ride back to Earth. Or you have to use Starships to bring Hydrogen off of Mars.
I am wondering about Nuclear>Thermal>Other Fluids.
What about Nuclear>Thermal>Water? I recall that that is about as good as chemical. But water is able to help shield from radiation, and is relatively passive in containers, not having so much problem from boil-off.
And water might be brought up from Mars. You could clean the ice water and bring it up with a Starship.
So, you only have to cook up Methane and Oxygen to run the Starship which is a water tanker. You also have to melt and clean the Mars ice water, but as I have said, water in tanks may help to protect from radiation of a nuclear reactor.
So, you might have water cooled Nuclear>Thermal>Water reactors
The rotation rate for the web to keep it inflated could be rather small, so the tensile force the web has to deal with would be miniimized.
So, with that as well, you might have some residual water after the initial thrusting event(s). So that may serve as radiation protection as well.
At first perhaps water would be lifted to Earth-LEO and Mars-Low Orbit, but later on when things are better developed perhaps Oxygen for Water may come from our Moon or Phobos or Deimos. In that case Hydrogen would have to be lifted from Earth or Mars and converted to be part of water as soon as possible.
What do you think?
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Last edited by Void (Today 13:50:52)
Be careful what you wish for.
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