Most spacecraft use solar panels to power their equipment — but missions to places such as the shadowed craters of the Moon or the deep Solar System can’t rely on energy from the Sun. Could nuclear fuel, with its high energy density, be a promising alternative?

In this film, Nature explores the work of a spin-off firm from the University of Leicester, UK, called Perpetual Atomics. Researchers at the company have been developing technology that uses by-products from nuclear reactors on Earth to fuel missions in space.

These space nuclear-power systems will be used on board the Rosalind Franklin Mars rover, which is due to be sent to the red planet by 2030.