NASA has announced that it will work with DARPA (Defense Advanced Research Projects Agency) to restart the Cold War-era “Nuclear Thermal Rocket Engine” technology.
NASA will be responsible for the development of the rocket engine itself, while DARPA is responsible for building the rocket carrying the engine. NASA hopes to demonstrate the nuclear thermal rocket technology in 2027 and prepare for future missions to Mars.
Image source NASA
The company’s main goal is to develop a new nuclear-powered rocket that will be ready for future missions to Mars.
The nuclear-powered rocket NASA is trying to develop does not burn nuclear material directly as fuel, but only uses the nuclear reactor as a “heater”. The actual thrust is generated by piping hydrogen gas through the reactor, which expands rapidly when heated and is ejected by nozzles to generate thrust. This technology was already proposed in the 1940s, and the U.S. began experimenting with it in the 1950s.
Unlike direct fueling by nuclear reactions, the nuclear reactions of a nuclear thermal rocket engine are closed and, if fully operational, no nuclear material will leak. However, if the rocket explodes accidentally before reaching outer space, there is still a possibility of spreading nuclear material into the atmosphere. To avoid unnecessary risk and to avoid funding shortfalls, NASA ended research on nuclear heat engines in 1972.
Now with decades of experience in miniaturizing nuclear power systems, improved rocket safety, and a better understanding of nuclear safety, NASA believes that the risks of nuclear thermal rocket engines have come to a manageable level and are worth trying to shorten the voyage to Mars. Nuclear thermal rocket engines can be used without carrying oxidizers because they are not powered by chemical reactions. This allows the nuclear thermal rocket engine has more than three times the efficiency of ordinary chemical engines, in addition to providing more power, but also allows the spacecraft to Mars to carry more supplies.