Skipjack wrote:Paul, at least there is a little bit of funding for all that. I know about a small NTR project that has been going on for a while ( I posted about it a year ago, or so) and NASA is funding fusion research (on a small level), like John Sloughs fusion rocket engine.
Skipjack:
Don't get me wrong, NIAC grants and small 2-to-20 person nuclear study teams are needed to keep our eyes on the nuclear power prize in an educated way, but they are no substitute for a long term space nuclear power program tailored to be able to support both scientific and human spaceflight requirements that is spending real $$$ on real hardware. And in my view what’s needed now is a closed-cycle nuclear electric propulsion (NEP) program that has the goal of developing a space qualified 1.0-to-10 MWe output electric power plant that has an operational specific mass of 5-to-10 kg/kWe which includes its reactor, radiation shielding, internal structures, thermal radiators and controls with all of these subsystems being constructed as a turn-key power module ready for the next customer's mission. The open-cycle NTR isn't much good past Mars due to its low Isp and it's a political hot potato in regards to ground testing on Earth, so in my view its just not worth the development pain verses its performance gain over chemical rockets in getting payloads to LEO and GEO. Now if we could build single stage to orbit vehcile using NTR, my analysis would be different, but that just isn't going to happen in the USA due to the current nuclear bomb perceptions of the populace and their politians.
IMO power plants are always the long pole in the tent in both in development cost and schedule impact for any project and they have to be developed first to take the largest risk out of any program of note. So my recommendations are along the lines of picking up where the USA’s SP-100 NEP ~2.0 MWt program left off and start developing it along the above specifications with its first use to be able to drive an array of the currently available 20 kWe, 1.07N, ~2,800 second Isp Hall Effect thrusters that could be replaced with any competing electric thrusters that might come along, like Ad Astra’s VASMIR or longer term, Woodward's M-E thrusters or White's Q-thrusters and Warp drive.
BTW, 1.0 MWe is only 1,336 horsepower (hp) so talking about a few megawatts of power is just talking about building a dragster with several thousand hp and no big deal, except in space…
Best,