Leicester combines expertise with NASA to power spacecraft into new frontiers

Scientists from the University of Leicester and NASA are working together on combining radioisotope power systems with high efficiency power convertor technology to enable spacecraft to venture into new frontiers.

The University of Leicester has signed an International Space Act Agreement (ISAA) with NASA that will enable collaborative use of engineering design and laboratory resources at NASA Glenn Research Center in Cleveland, Ohio. It will support a collaboration between the Space Nuclear Power teams at Space Park Leicester, the University’s £100 million science and innovation park, and NASA Glenn for a test campaign and to advance from concept work to combining hardware.

The two groups are collaborating on a project to combine electrically heated simulators of americium heat sources being developed at the University with Stirling power convertor technologies at NASA. It builds on the development of radioisotope power systems at the University of Leicester, which has been ongoing for over a decade and has been funded by the European Space Agency ENDURE programme. These power systems use the heat generated from the decay of radioisotopes and can be used to provide heat to spacecraft, or converted to electricity to power key subsystems. 

The heat sources being developed by the University are powered by Americium-241, which is an alternative to the Plutonium-238 heat sources that have historically been flown in space. These power systems could be used in space missions where there is limited access to solar power, such as the shadowed craters on the Moon, or outer solar system. 

This project will look at ways to generate electrical power from the University’s heat sources at higher efficiencies using Stirling convertor technology in what are called Radioisotope Stirling Generators (RSG). These generate electricity by heating and cooling a ‘working gas’ inside a sealed system causing a piston to move back and forth, which in turn produces electrical power. A unique feature of the University of Leicester heat source design is that it can be coupled to three Stirling convertors, and so could be more reliable for future space missions.

The work builds upon previous collaborations between the two groups, where they investigated the feasibility of the Americium-fuelled RSG concept with a lunar rover mission study. The teams have since been developing hardware for an electrically heated breadboard test article using electrically heated simulators which mimic the shape and outer materials of the heat source, due to the challenges of working with radioactive material. 

The current work is being funded by the UKSA International Bilateral Fund, and NASA’s Radioisotope Power Systems Program.

Dr Hannah Sargeant, Research Fellow in the Space Nuclear Power Team at Space Park Leicester, said: “We are excited to bring our novel heat source design to NASA’s Glenn Research Center for testing with Stirling convertor technologies. The International Space Act Agreement is a critical step in this collaboration as we can now progress from concept to test. The results of this work will help us to optimise the design for future space missions, and generate electricity in some of the most challenging environments such as the 14-day lunar night, or the outer solar system. We’re grateful for the support from UK Space Agency and NASA in this collaboration.”

Jessica Fell, Head of International Relations at the UK Space Agency, said: “The University of Leicester has a track record of leading the way in pioneering research on space technologies, and this ongoing work is instrumental in developing a commercial pipeline for radioisotopes used in space technologies. The international collaboration enabled by the UK Space Agency's International Bilateral Fund builds on this foundation, drawing on global expertise to advance our knowledge and strengthen the UK’s role in the global space community.”