As NASA prepares to put astronauts back on the surface of the Moon, it’s not losing sight of its other big goal: getting humans to Mars. For this reason, the US space agency advertisement a new partnership with DARPA, the Defense Advanced Research Projects Agency, to develop and demonstrate a thermonuclear-powered rocket.
The objective of this project is to make progress on a crucial point so that manned missions to Mars can materialize: to prove the feasibility of thermonuclear propulsion, which promises to be faster and more efficient than the methods currently used. According to NASA, using a space rocket with this type of motorization would bring enormous benefits in both the technical and safety aspects.
Reducing space travel times would imply fewer risks for astronauts, they say from the agency. In addition, crucial space on the ships would be freed up for more advanced instruments, more powerful communication equipment, and more supplies for crew survival, considering the length of the voyage.
“In a thermonuclear rocket engine, a fission reactor is used to generate extremely high temperatures. The engine transfers the heat produced by the reactor to a liquid propellant, which expands and is expelled through a nozzle to propel the spacecraft. Thermonuclear rockets can be three or more times more efficient than conventional chemical propulsion,” explains NASA.
NASA and DARPA will develop a thermonuclear propulsion system
Photo by Todd Trapani on Unsplash
The project announced by NASA and DARPA is really ambitious. Both agencies intend to conduct a space demonstration of their thermonuclear propulsion system starting in 2027, at the earliest. It remains to be seen if they manage to meet such an upcoming goal, considering that we are only four years away. Although it would not be surprising if the initiative suffers delays.
Regarding the hierarchies within this alliance, NASA will be in charge of leading the technical development of the thermonuclear propulsion engine. It will do so through its Space Technology Mission Directorate (STMD). While DARPA will provide the experimental spacecraft that will be used during the test in space.
It is worth clarifying that this alliance between the two organizations was born to continue with an already existing DARPA program, called DRACO. It has already been in development for a few years, with the aforementioned agency working alongside the United States Department of Defense.
In fact, in 2021, Blue Origin, Jeff Bezos’s aerospace company, won a contract to design a thermonuclear-powered spacecraft capable of flying in low-Earth orbit by 2025. While Lockheed Martin was given a similar task .
It is therefore not surprising that DARPA is leading the overall program and acting as the contracting body for all stages. The latter includes the development of the rocket and the parts that make up the engines, including the fission reactor, among many other responsibilities. Regarding the assembly of the motorization, engineers from both agencies will take charge of the task.
It is important to remember that, in 2020, the General Atomics company presented NASA with a concept of thermonuclear propulsion. Although for now it is unknown if this company will be one of the many involved in the DRACO program.
Photo: Glenn Research Center –NASA.
This is not the first time that thermonuclear propulsion has been discussed as a possibility to send manned missions to Mars. In fact, NASA already has significant experience in developing this type of engine for spacecraft, although it was never able to test it in space. The latter is what the alliance with DARPA is trying to remedy.
The last antecedent of NASA and thermonuclear space rockets dates from the NERVA program (Nuclear Engine for Rocket Vehicle Application), which began in the fifties and lasted until 1973. The project was born within the Atomic Energy Commission of United States and had purely military purposes. After all, the original intention was for its implementation in ICBMs.
However, it later became a civil initiative developed in conjunction with NASA to analyze the feasibility of thermonuclear propulsion in space travel. In fact, the NERVA roadmap was very ambitious, aiming to send astronauts to Mars in 1978. However, that never happened, due to its cancellation by the Richard Nixon administration.
NASA’s greatest success in the field of thermonuclear propulsion was with the NERVA XE engine. To the point that it was tested on the ground and considered prepared for the space agency’s missions to Mars. However, it was never implemented in a space demonstration.