Quote:
Originally Posted by Michael Thayne
Looking at this more, I'm kind of wondering why mass drivers weren't listed in Spaceships as TL8—sure mass driver propulsion hasn't been developed yet, but neither have Orion drives or nuclear thermal rockets, both TL7.
|
Actually, the NERVA project did test fire a nuclear thermal rocket and a small scale Orion (using conventional explosives) was flight tested before Orion was shut down by JFK. So both were fairly well developed in TL7.
The work done with Mass Drivers in the same period were more focused on using them to shoot material into lunar orbit (or the lagrange points anyway) than on useful propulsion of spacecraft. A mass driver rocket with the kind of stats listed in Spaceships is pretty scifi even by modern standards. It fires off it's propellant at ~6-9,000 m/s (roughly 3-4 times that of a modern railgun, meaning 10 times the energy). Worse still, in order to get an acceleration of 0.01G, it has to fire away the propellant at a sustained rate of measured in kilograms or even tons per second. Railguns require massive capacitor banks to recharge between shots, while this theoretical mass driver needs a constant supply of power.
Basically, Mass Drivers are TL9 because they require a TL9 power source. NTRs and Orions are TL7 because we actually built working prototypes of them in the Cold War.