How does it work?
““These more powerful and efficient nuclear thermal propulsion systems can provide faster transit times between destinations. Reducing transit time is vital for human missions to Mars to limit a crew’s exposure to radiation,” said Kirk Shireman, vice president of Lunar Exploration Campaigns at Lockheed Martin Space.”
Like every government job Lockheed lands: delays and cost overruns abound. Nothing much actually gets done, but Lockheed makes a fortune off of “development”.
/sarcasm
Steve
For those of you who may be nervous about the idea of a nuclear powered rocket launching from Cape Canaveral, it wouldn’t exactly work that way. A conventional chemical rocket would boost the reactor into Earth orbit, and then the nuclear engine would be turned on for the first time to take the spacecraft to Mars or wherever. Fresh uranium fuel has low radioactivity and would not cause a huge problem, even in the event of a crash.
Another article below from Nuclear News. BWXT will provide the nuclear equipment and fuel.
It sounds like Project Orion is getting another chance.
The idea of rocket propulsion by combustion of an explosive substance was first proposed by Russian explosives expert Nikolai Kibalchich in 1881, and in 1891 similar ideas were developed independently by German engineer Hermann Ganswindt. Robert A. Heinlein mentions powering spaceships with nuclear bombs in his 1940 short story “Blowups Happen”. Real life proposals of nuclear propulsion were first made by Stanislaw Ulam in 1946, and preliminary calculations were made by F. Reines and Ulam in a Los Alamos memorandum dated 1947.[1] The actual project, initiated in 1958, was led by Ted Taylor at General Atomics and physicist Freeman Dyson, who at Taylor’s request took a year away from the Institute for Advanced Study in Princeton to work on the project.
Not really. The current plan will not use atomic explosions like Project Orion. The heat from a fission reactor will simply convert a cold fluid to gas. The expanding hot gas will be propelled out the back end of the craft, in the same way as a conventional rocket engine.
There is no great scientific leap needed to develop these engines, but there will certainly be a lot of engineering required to make it work.
Readers of this thread may be interested to know that nuclear reactors have already flown to space.
In 1965, the US launched the SNAP-10A satellite, which included a small fission reactor and electrical generator. The craft also included a cesium ion thruster which was tested as part of the program.
The reactor operated for 43 days before a voltage regulator failed and the reactor shut down. It still orbits the Earth, and will be up there for an estimated 4000 years. However, parts of the satellite have reportedly come off, possibly because of a collision with a piece of space junk.
^ ^ ^ ^ ^ ^ ^
The Soviets/Russians have launched over 30 nuclear reactors into space over the years. Those satellites used reactors to power radar surveillance systems in low Earth orbit. After their missions completed, the reactors were put into high Earth orbit, so they wouldn’t burn up in the atmosphere. However, there were a few failures with some of the missions. You may recall a Soviet satellite burning up over Canada in 1978, and contaminating an area with radiation.
^ ^ ^ ^ ^
In addition to the reactors, both the US and Soviets/Russians have launched numerous spacecraft with radioisotope thermoelectric generators (RTGs). These are not fission reactors, but use the heat of radioactivity to generate electricity. In the US, plutonium-238 is used as the heat source. The rovers currently exploring Mars, for example, use RTGs for their power. At that distance from the sun, and with the dusty Martian atmosphere, solar panels would not work as well.
Wikipedia article about the SNAP-10A satellite here.
About the Soviet RORSAT reactors here.
About RTGs here.