notes.husk.org. tagged energy.

“ Orion works by the (seemingly insane, but actually quite effective) method of throwing nuclear bombs behind the spacecraft and having it ride the blasts. The hot gasses from the detonations hit a heavy pusher plate at the back of the ship and drive it forward. NSWR [nuclear salt water rocket] is similar, but it instead uses a solution of fissionables in salt water that spontaneously explodes as it leaves the rocket nozzle. Both systems cleverly shift the propulsive reaction outside the spacecraft, eliminating the need to deal with most of the heat it produces and allowing it to be made much more energetic. ”

Memphet’ran on spacebattles.com, as featured by Sarah Pavis, guest editing kottke.org.

I’d heard of Orion, but not nuclear salt water rockets, which get impressive performance:

One design would generate 13 meganewtons of thrust at 66 km/s exhaust velocity (compared to ~4.5 km/s exhaust velocity for the best chemical rockets of today). Another design would achieve much higher exhaust velocities (4,700 km/s) and use 2,700 tonnes of highly enriched Uranium salts in water to propel a 300 tonne spacecraft up to 3.6% of the speed of light.

Of course, there are slight drawbacks to using these things in a biosphere:

a NSWR would eject massive quantities of superheated steam, still containing fissioning nuclear salts. Terrestrial testing might be subject to reasonable objections; as one physicist wrote, “Writing the environmental impact statement for such tests […] might present an interesting problem …”

2012-03-28

post/20081417020

photo 23:07:21

Dymaxion map showing world energy usage, via iamdanw.

2012-03-15

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quote 18:33:05

“ The environment movement has a choice. It has to decide whether it wants no new fossil fuels or no new nuclear power. It cannot have both. I know which side I’m on, and I know why. ”

George Monbiot in the conclusion to No Primrose Path, his post (also on the Guardian) about why he co-signed a letter to David Cameron urging him to support nuclear power (and to ignore the letter suggesting otherwise from four former directors of Friends of the Earth).