Orion Starship - Heat Sink

American nuclear pulse orbital launch vehicle. The heat sink version of Dyson's starship would have a pusher plate made of copper. This would require 5 million metric tons of exposed surface to absorb and then reradiate 1 megaton of bomb energy. The plate would have to be 20 km in diameter.

15 billion kg of deuterium would be used in 30 million bombs. The spacecraft would have an empty weight of 10 million tons and a loaded weight of 40 million tons. The bombs would explode 120 km behind the pusher plate at 1000-second intervals over 500-year acceleration and deceleration periods. Payload would be several million metric tons, enough to house a city of 20,000 people. The starship would reach a velocity of 1000 km/sec. Effective exhaust velocity would be 150,000 seconds. The cost would be equal to the entire Gross National Product of the United States. This generation ship would take 1800 years to reach Alpha Centauri.