/sci/ - Science & Math

>>11871298
You can push NTPRs to have higher mass flow rates by using a fuel element with a larger surface area, however the liquid propellant can only absorb so much heat (energy) from the nuclear fuel, ISP for NTPRs seems to be capped around 900-1000s. At least in theory though a groove ring fuel element could let you get TWRs in the low 100's range, making them more akin to lower end bipropellant LPREs than it's anemic sister rocket NERVA. The DUMBO concept did something similar, forcing propellant to travel through many folded plates of a cermet fuel element to reach the nozzle, thus allowing more liquid to be heated inside the reactor, thus allowing for greater mass flow rate and in turn greater thrust.

ISP is determined by how much energy the propellant can carry out of the engine per unit of it's mass, TWR is determined by the sheer quantity of that propellant the engine can move through itself.

>>11771207
If I had billions I'd sink it into radically shrinking atomic power generation technology, and discovering the best way to manufacture high-strength, high-temperature, high-corrosion tolerant cermet materials.
If you can solve the cermet problems you can get Nuclear-Thermal rockets with TWRs much closer to conventional chemical rockets with fuel that is strong enough to avoid being corroded or chipped and thus released into the environment. Working off of the back of that you could have safe, reliable, reusable atomic booster stages, or high-TWR NTPR second stages.
Substantially shrinking power reactors would also allow for much larger operations in space, especially beyond the orbit of Earth where solar power suffers radically diminishing returns. It will be anemic on Mars and practically useless in the Jovian and Saturnine systems.