In the pursuit of landing humans on Mars, NASA is placing a significant bet on nuclear rocket engines as the key to transporting astronauts to the red planet. The agency recently announced a partnership with the Defense Advanced Research Projects Agency (DARPA) to develop a rocket that utilizes nuclear propulsion, enabling expedited journeys to deep-space destinations like Mars. This groundbreaking technology promises to reduce travel time and make long-duration spaceflights less hazardous for crew members.

A conventional spacecraft powered by liquid fuel combustion typically takes around seven to eight months to reach Mars. However, nuclear rocket engines have the potential to trim at least a third of that duration, as stated by scientists. The shortened journey would offer crews greater flexibility in their missions to Mars, allowing them to spend three to four weeks on the planet’s surface before returning within a reasonable timeframe, as explained by NASA Administrator Bill Nelson.

Apart from time savings, a shorter round trip would also limit astronauts’ exposure to cosmic radiation during their time in space. Without the protective shield of Earth’s atmosphere and magnetic field, humans can receive the equivalent of an entire year’s worth of radiation in just one day. For Mars missions, this means potential radiation levels 700 times higher than on Earth, according to the European Space Agency. To mitigate these risks, DARPA is developing a rocket powered by nuclear thermal propulsion, known as the Demonstration Rocket for Agile Cislunar Operations (DRACO).

The DRACO system employs high heat from a fission reactor to convert liquid propellant into a gas, which then powers the spacecraft through a nozzle. This type of propulsion generates greater thrust and is at least three times more efficient than chemical rockets, as confirmed by NASA. Consequently, less onboard fuel is required, allowing for additional cargo, scientific experiments, or equipment to be transported to the Martian surface.

It is worth noting that despite utilizing nuclear power, the proposed system would utilize low-enriched uranium rather than weapons-grade highly enriched uranium, prioritizing safety, as stated by NASA Administrator Bill Nelson. He emphasized that tests of the nuclear rocket engine would not take place on Earth but rather in space, with safety being of utmost importance. The first DRACO demonstration could potentially occur as early as 2027.

Daniel Dumbacher, executive director of the American Institute of Aeronautics and Astronautics, hailed nuclear propulsion as a significant stride forward for space exploration. While missions to Mars inherently pose numerous health risks for humans, nuclear technology has the potential to mitigate some of these consequences, including the psychological toll on crews confined to cramped quarters for extended periods.

The concept of a nuclear rocket engine was initially conceptualized in the 1960s but stalled following incidents such as the Three Mile Island accident in 1979 and the Chernobyl disaster in 1986, which dampened public opinion toward nuclear technology. However, the current era presents renewed interest and political will to explore alternative fuels, according to NASA Administrator Bill Nelson. DARPA Director Stefanie Tompkins echoed this sentiment, emphasizing that this is the opportune moment in history to advance and unlock the full potential of nuclear propulsion.

Tompkins acknowledged the promising nature of nuclear propulsion from the 1960s and expressed gratitude for the groundwork laid by previous pioneers. The present generation has the privilege to build upon their achievements and push the boundaries of space exploration further.

By Impact Lab