4 ms·

The winning design assumes redundant toroidal fusion reactors.

• jmyeet 1y ago
  Having a fusion engine or fusion reactor is basically hand-waving away the energy problem. Controlled fusion has a fundamental problem: neutrons. Even if you solve the problem of container destruction (ie neutron embrittlement), which is significant, you still face the problem of significant energy loss to the system through high-energy free neutrons. Stars solve this problem by simply being really large so a free neutron can't really go that far without hitting another nucleus, particularly because fusion happens at the core. The hope with commercial fusion research is that we can somehow avoid the container destruction issue and have sufficient energy generation (given the energy inputs) despite the free neutron energy loss but it's unclear if that'll ever happen.
  • protocolture 1y ago
    IIRC (Its a long document, and I only skimmed it) they assumed 20% efficiency on behalf of the reactors. I think they just wanted a plausible future energy source that they didnt have to look at too closely. My first issue with the design is that it looked like a decent percentage of the planet would have to be launched into space just to build the thing. A lot of the space math looked alright, but theres several issues of practicality. >Even if you solve the problem of container destruction No idea if this is related, but everywhere they needed 1 reactor, they had 4. 2 in active/active failover, and 2 cold spares. It seemed relatively easy for them to perform maintenance on these. But its just heaps more launch mass, heaps more acceleration fuel, and a lot more deceleration fuel.