The Defense Advanced Research Projects Agency (DARPA) receives a reward of $22 million worth of contract with General Atomics in order to design small nuclear reactors. Small reactors are designed for space propulsion, an announcement by the agency on 9th April.
General Atomics has its base in San Diego, California. General Atomics is in the first phase of a program which is known as DRACO. It is short for demonstration rocket for agile cislunar operations. The project aims to showcase nuclear thermal propulsion alternatively using a nuclear reactor to heat up rocket fuel to generate thrust.
In May 2020 DARPA’s Tactical Technology Office solicits in a proposal broad agency announcement. The focus remains to test a nuclear thermal propulsion system by 2025. Applications of space propulsion systems in today’s world include electric and chemical propulsion. However, the other options might be beneficial for future exploration beyond Earth’s orbit. “The intention behind the DRACO program is to develop a unique nuclear thermal propulsion technology. Other than propulsion technologies in application today, NTP aims to achieve high thrust-to-weights which are similar to chemical propulsion. The efficiency with these programs increases the efficiency by two to five times. The capability to monitor cislunar space – the volume between the Moon and Earth may require a leap-ahead in propulsion technology”, said DARPA.
The DRACO program aims to showcase a nuclear thermal propulsion system in orbit. A nuclear reactor heats up the propellant to very high temperatures. This process completes before the hot propellant expels through a nozzle to form thrust.
Christina Back is the vice president at General Atomics Electromagnetic Systems in charge of nuclear technologies and materials. According to Back, “nuclear thermal propulsion is a jump ahead of traditional propulsion technology. In addition, it enables the spacecraft to travel immense distances quickly. An agile spacecraft is critical to sustaining space domain awareness and essentially decrease transit times in the massive cislunar region.”
Christina also mentions that for space exploration such as human missions to Mars, nuclear propulsion allows versatile launch windows which enables longer stays on the planet itself. The pioneer in research for nuclear thermal propulsion in the 1960s is NASA. However, with the shift in priorities, efforts went down in the 1970s.
As per the NASA news release, “Once again there is a recognition that nuclear thermal propulsion is a viable and powerful alternate in order to explore Mars and other regions.”
A study by the National Academies in February for which NASA is the sponsor said that the mentioned approaches decrease travel time of expeditions to Mars. However, it must overcome all the technical challenges. The approaches include nuclear thermal propulsion and nuclear electric propulsion.