As an astronaut you would not want to be blasted into space from a giant air gun — but it makes sense for certain sturdy payloads:
The gun is based on a smaller device Hunter helped to build in the 1990s while at the Lawrence Livermore National Laboratory (LLNL) in California. With a barrel 47 metres long, it used compressed hydrogen gas to fire projectiles weighing a few kilograms at speeds of up to 3 kilometres per second.Now Hunter and two other ex-LLNL scientists have set up a company called Quicklaunch, based in San Diego, California, to create a more powerful version of the gun.
At the Space Investment Summit in Boston last week, Hunter described a design for a 1.1-kilometre-long gun that he says could launch 450-kilogram payloads at 6 kilometres per second. A small rocket engine would then boost the projectile into low-Earth orbit.
While humans would clearly be killed and conventional satellites crushed by the gun’s huge g-forces, it could lift robust payloads such as rocket fuel. Finding cheap ways to transport fuel into space will lower the cost of keeping the International Space Station in orbit, and in future it may be needed to supply a crewed mission to Mars.
The gun would cost $500 million to build, says Hunter, but individual launch costs would be lower than current methods. “We think it’s at least a factor of 10 cheaper than anything else,” he says.
Franklin Chang-Diaz, a former astronaut and physicist at the Ad Astra Rocket Company based in Webster, Texas, says a launch gun might make more sense on the moon, where there is no atmosphere. “You don’t have to worry about drag or heating or anything like that,” he says.
(Hat tip to Nyrath.)