Sunday, May 08, 2005

Nuclear Rockets Will Take Us There

Why is it so hard, so dangerous, and so expensive to get into space? It's because we rely on huge semi-controlled explosions to take us there. Who in there right mind would ever strap themselves above tens of thousands of pounds of explosives and press ignite? But that is what we ask our astronauts to do every time we send them to space. But this isn't the way it has to be.

As you guessed, I'm talking about nuclear power. But isn't that dangerous, isn't Nuclear scary? Nuclear power in general has gotten a bad rap (Nuclear power as it is practiced in the U.S. deserve that reputation, but that a topic of another post). With modern nuclear technology there is no risk of meltdown, fuel and equipment are recycled and overall radiation levels are reduced.

A nuclear rocket would emit NO radiation. The technical term for such a device is a nuclear Thermal Rocket. A nuclear core is used to heat hydrogen gas to extreme temperatures and expel it out the rear of the rocket. The hydrogen fuel it uses cannot pickup radiation from the core. The Gas Core Nuclear Rocket design uses a Uranium hexafluoride core spun into a vortex with a fused-silica shield used to separate the hydrogen from the radioactive gas. Approximately 10 pounds of gas would be needed. For details about the concept and the issues involved, read Anthony Tate's excellent article on the subject.

These engines would finally allow the ability to easily leave the surface of the planet and reenter again safely. Imagine simply slowing down enough in space using a nuclear rocket, eliminating entirely the need for much of the heat shielding used on current missions. With a combination of nuclear thermal and nuclear electric powered ion engines, the entire Solar system would be at our feet.


Most of the technology for nuclear rocket engines was developed in the 1960s in Project NERVA by NASA for use on a manned mission to Mars. When it was canceled in 1969 when it was apparent the Soviets were not going to launch their own manned Lunar and Mars missions, the project has already conducted test firings of a nuclear rocket engine which showed how effective and powerful the system would be.

Nuclear rocketry is seeing a recent reemergence in NASA's Project Prometheus which received funding this year of $430m. For more information about Project Prometheus read the Space.com article from 2003.