General Atomics was given a $22 million contract by the Defense Advanced Research Projects Corporation to develop a compact nuclear reactor for space propulsion; the agency reported April 9. General Atomics, located in San Diego, was chosen for the first step of the DRACO program, which stands for demonstration rocket for agile cislunar operations. The project aims to show nuclear thermal propulsion, which involves heating rocket fuel to produce thrust. In May 2020, DARPA’s Tactical Technology Office issued a “big agency statement” seeking proposals. By 2025, a nuclear thermal propulsion device will be tested in space.
Electric and chemical propulsion systems are currently in operation in space; however other options will be needed for potential exploration outside Earth’s orbit, according to DARPA. “The DRACO program aims to create a novel nuclear thermal propulsion system. Unlike current propulsion technologies, NTP can achieve strong thrust-to-weight ratios that are comparable to chemical propulsion but with about 2 to 5 times the performance.’ According to DARPA, monitoring cislunar space – the amount of space between the Moon and Earth – would necessitate a “breakthrough in propulsion technology,” stated DARPA.
On-orbit, the DRACO program would try to show a nuclear thermal propulsion device. To generate thrust, a nuclear reactor heats propellant to high temperatures before expelling it via a nozzle. Nuclear thermal propulsion, according to Christina Back, who serves as vice president in charge of the nuclear technologies as well as materials at the General Atomics Electromagnetic Systems, is a “step ahead of traditional propulsion technology and would allow spacecraft to fly vast distances quickly.”
Back told SpaceNews that “agile spacecraft are crucial to preserve space domain understanding and greatly reduce transit periods in the large cislunar region.” “Nuclear propulsion would make for further mobility of launch windows, as well as extended stays on the planet itself,” Back added, referring to human missions to Mars.
In the 1960s, NASA initiated nuclear thermal propulsion research, but interests changed, and activities were scaled down in the 1970s. “There is once again the acknowledgment that the nuclear thermal propulsion is a feasible and efficient choice for exploring Mars and other destinations,” according to a NASA press release. According to a February report funded by NASA, nuclear thermal, as well as nuclear electric propulsion methods, could cut expeditions to Mars’ travel time in half. However, they must resolve major technological challenges.