UK sets sights on nuclear rocket for faster deep-space exploration

Nuclear propulsion could transport astronauts to Mars in just three months, roughly twice as quickly as the current fastest method.

Such an improvement makes the technology highly promising, so the UK Space Agency (UKSA) has announced a new collaboration with Rolls-Royce to study how nuclear power and technologies could be used for space exploration.

The research contract will see planetary scientists work together to explore the potential of nuclear power as a more plentiful source of energy, capable of travelling further out into deep space in the decades to come.

Nuclear propulsion, which would likely involve using a fission reactor to heat and accelerate propellants like hydrogen at huge speeds, could revolutionise space travel. By some estimates, it could be twice as efficient as the chemical engines that power rockets today.

“If we're serious about human exploration of the outer solar system then nuclear thermal is probably the only way to actually do that,” wrote Thomas Cheney, executive director of think tank Centre for a Spacefaring Civilisation, on Twitter.

“Just unsure of what the UK government expects to be able to do that has not already been done, this is hardly unexplored territory.”

Nuclear propulsion is an idea that has existed since the 1950s, when NASA’s Project Orion explored nuclear pulse propulsion – ejecting small directional nuclear explosives, which would detonate behind the rocket and propel it forward. Various other projects have been attempted throughout the years, and NASA has restarted research in recent years ahead of a planned test flight in 2024.

Thermal propulsion would be slower than the explosive pulse propulsion, but without many of the associated challenges. It could enable two- to three-times bigger mission payloads.

“Space nuclear power and propulsion is a game-changing concept that could unlock future deep-space missions that take us to Mars and beyond,” said Dr Graham Turnock, chief executive of UKSA.

“This study will help us understand the exciting potential of atomic-powered spacecraft, and whether this nascent technology could help us travel further and faster through space than ever before.”

The method would not just save time on missions – it could also radically reduce the dose of radiation experienced by astronauts, which increases the longer you spend in space. A small nuclear power generator for propulsion is also promising thanks to its reliability, meaning a craft would not be dependent on patchy fuels or dwindling sunlight further out in the solar system.

Nuclear network

A nuclear space power project could create new skilled jobs around the UK, supporting the burgeoning sector, the government said.

Science minister Amanda Solloway said: “Nuclear power presents transformative possibilities for space exploration and this innovative study with Rolls-Royce could help to propel our next generation of astronauts into space faster and for longer, significantly increasing our knowledge of the universe.”

Dave Gordon, UK senior vice-president of Rolls-Royce Defence, said: “We are excited to be working with the UK Space Agency on this pioneering project to define future nuclear power technologies for space. We believe there is a real niche UK capability in this area and this initiative can build on the strong UK nuclear network and supply chain.”