(See my other Space and Propulsion related posts) – I came across the article “Earth To Mars In 100 Days? The Power Of Nuclear Rockets” today and wanted to share it.
The idea of a nuclear rocket engine was developed in the 1960s for NASA. The research was led by Werner von Braun and successfully tested in Nevada.
What is a nuclear thermal rocket?
A conventional chemical rocket carries combustible chemicals which are ignited, then the resulting gases flow out of a nozzle propelling the vehicle. In a nuclear rocket, a small marble size chunk of Uranium fuel undergoes fission. This energy released heats hydrogen to very high temperatures (nearly 2500 C). The hydrogen is then expelled from the vehicle in a nozzle like on chemical rockets. The difference is that nuclear propulsion is two to three times as efficient. Tests were carried out starting in 1955 that have proven that this technique will work. Testing was discontinued in 1973.
Where are we Now?
The original design required highly-enriched uranium. Current designs will most likely rely on low-enriched uranium. This would make nuclear propulsion systems safer to work with. On May 22, 2019, the US Congress approved $125 million to fund new nuclear thermal propulsion development.
Another alternative being researched is using fusion instead of fission for propulsion. The Princeton Plasma Physics Laboratory is working on what they call the Direct Fusion Drive. Applied Fusion Systems is also at work on a fusion alternative.
Whether it is fission in the short term or fusion in the long term, the prospects for nuclear-powered rockets looks very positive. Read the full article for more details.