Re: Someone's been watching
different technology
the Fireflash used a nuclear reactor to heat air passing through what were effectively ramjets. The heat transfer from the reactor to the jets was via Sodium-Potassium alloy - an extremely flammable/water reactive liquid metal which has good thermal conductivity (its used as the primary cooling circuit in nuclear subs)
Of course that wouldn't give any initial thrust at startup as the air needs to be moving through the jet before you can heat it, so initial takeoff was powered by what were described as "chemical engines" but were presumably solid fuel rockets
information remembered from TV21's Christmas annuals back in the 1960's, the technical detail was quite surprising given the target audience