We’re building nuclear spaceships again. NASA thinks we’re going to need them

NASA has teamed up with DARPA, the Pentagon’s research arm, to bring to life an idea that failed half a century ago. Why do we need nuclear rockets now?

The idea dates back to the 1950s. The U.S. Air Force began researching nuclear-powered intercontinental missiles under the so-called Project Rover. Development then moved into the space sector under the aegis of NASA and the Atomic Energy Commission (AEC) with the NERVA project (Nuclear Engine for Rocket Vehicle Applications).

In theory, it was a simple concept: pass liquid hydrogen through a nuclear reactor to heat it, then expel it out of a rocket nozzle to generate thrust. Dubbed a nuclear thermopropulsion rocket (NTR), this system promised unprecedented fuel efficiency.

In practice, building nuclear spaceships It proved to be very complicatedExtreme temperatures, hydrogen corrosion and a lack of gravity complicated every step. The NERVA project was cancelled after 23 prototypes in 1973, when NASA began prioritizing low-Earth orbit in its space program.

Images | Los Alamos National Laboratory, Dono decided to take up the concept for a national security reason: China’s advances in space. Enter the DRACO (DemDonstration for Rocket to Agile Cislunar Operations) project, a joint effort by DARPA and NASA with Lockheed Martin as prime contractor. The $500 million contract, approved last year, calls for a technology demonstrator to be launched by 2027.

DRACO promises unprecedented speed and efficiency; the first rocket capable of making trips to Mars in three to four months instead of the usual six to nine months. What sets it apart from the prototypes of the 1960s and 1970s is that it uses a new type of fuel, low-enriched uranium (HALEU), to reduce risks and regulatory complications.

BWXT Technologies, the company in charge of building the experimental vehicle’s reactor, told Ars Technica“We have created our own nuclear fuel formula that can withstand reactor temperatures without cracking.” Still, project engineers have had to overcome problems that plagued the NERVA program, such as hydrogen corrosion and the shedding of material from the reactor core.

Why we need nuclear rockets. Greater speed and efficiency means less time spent traveling through space, which reduces radiation exposure and provisions needed on trips to Mars. It’s a crucial leap forward for astronauts’ health and safety.

But the potential applications of this technology go beyond space exploration of the solar system. Nuclear rockets could become the backbone of a new cislunar transportation system, acting as “space tugs” to move payloads between Earth and the Moon.

However, the project is not without controversy. Critics question the real need for nuclear spacecraft in the face of chemical alternatives, such as the emerging cryogenic propellants. Others are more concerned about the implications of these developments for the militarisation of space.

Images | Los Alamos National Laboratory, DARPA

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