TL9 Spaceships

[Apache]

Originally Posted by sir_pudding

Yeah, but then we are back to the "abstract space-faring civilization" that the OP isn't asking about. The political status quo of Earth as it is simply doesn't care about space travel and is pathologically afraid of nuclear reactors.

No, Western countries are pathologically afraid of nuclear reactors.

I could see Japan, China, India or Russia all deciding to use nuclear pulse, altho Japan probably wouldn't use it in atmo...they (the Japanese) would most likely use laser-launch to boost anything to orbit, and then light off the drives.

[sir_pudding]

Originally Posted by Apache

I could see Japan, China, India or Russia all deciding to use nuclear pulse, altho Japan probably wouldn't use it in atmo...they (the Japanese) would most likely use laser-launch to boost anything to orbit, and then light off the drives.

I don't see any of them risking international ire for whatever marginal benefits that space offers any time soon.

[Nyarli]

I don't see why use of any TL9 drives' designs from Starships in interplanetary space should provoke international ire(well, except Orion, of course).

[sir_pudding]

Originally Posted by Nyarli

I don't see why use of any TL9 drives' designs from Starships in interplanetary space should provoke international ire(well, except Orion, of course).

You have to get them into interplanetary space in the first place, and that's where people are going to freak out. Fusion drives with no radioactive components might be acceptable, but the international community isn't going to be happy with anybody that tries to boost radioactive or antimatter fuels from Earth to space.

[Ulzgoroth]

Originally Posted by sir_pudding

You have to get them into interplanetary space in the first place, and that's where people are going to freak out. Fusion drives with no radioactive components might be acceptable, but the international community isn't going to be happy with anybody that tries to boost radioactive or antimatter fuels from Earth to space.

Aren't space-based RTGs quite common?

Of course, there may be a major difference of quantity if you're boosting an Orion system.

[sir_pudding]

Originally Posted by Ulzgoroth

Aren't space-based RTGs quite common?

They exist, but not without controversy, and with very small amounts of fuel.

[johndallman]

Originally Posted by Ulzgoroth

Aren't space-based RTGs quite common?

There have been sizable protests about them. NASA's latest Jupiter mission, Juno, does not use them. Reasons for this include improved solar panels, spacecraft electronics that use a lot less power (flash drives vs. tape recorders), the problem that nobody's making Pu-238 any more ... and the protests.

[Apache]

Originally Posted by sir_pudding

I don't see any of them risking international ire for whatever marginal benefits that space offers any time soon.

We're not talking now. We are talking about TL9, and a supposed reason why a country would see a reason to use these drives. Maybe they discovered Handwavium-234 on Luna (or Mars)....maybe they found a 1x3x9 black monolith floating around Jupiter.

Russia and China already pretty much ignore "international ire", such as it is, and Japan and India will do whatever benefits Japan and India, and play patty-cake with the neo-luddite morons later, just as they do now.

[teviet]

Re: magsails:

Originally Posted by sir_pudding

Other options might be cheaper in some applications if you are more worried about expense over velocity, but otherwise they seem like a pretty good choice in real-life too.

They are pretty much the best real-life choice, for suitably broad definitions of "real life". We have yet to demonstrate superconductors that can operate at the required temperatures, but if you take modern high-T superconductors and say "like that only up to 350K" then you get very impressive performance.

Plasma sails, OTOH, require consumables, and I would wager that the concept proposals likely err on the side of optimistic specific impulses.

TeV

[wellspring]

BTW, how does a fission reactor work in space in the first place? Do you have to rotate it for gravity, or does it use something other than convection to operate?