The European Space Agency has revealed that it has designed a system in which a lander would supply power to a rover by shining a laser on it from a distance of up to 15 km. The laser-powered rover would explore the permanently-shadowed craters around the Moon’s polar regions. The system has been funded by ESA’s Discovery & Preparation programme.

Various space agencies such as NASA and ISRO have revealed that these permanently shadowed regions are rich in hydrogen. The presence of hydrogen indicates that water ice can be found there.

If water ice is discovered, it would be valuable to lunar colonists, as it could be used as “a source of drinking water, oxygen for breathing, as well as a source of hydrogen rocket fuel.”

It was previously suggested that the rover should be fitted with nuclear-based radioisotope thermoelectric generators taking into consideration the absence of solar power and very low temperature, around –240°C, 30 degrees above absolute zero.

However,  it was found that thermoelectric generators could warm up the rover such that “prospecting and analysing ice samples actually becomes impractical.”

When this plan proved impractical, scientists resorted to a laser-based power system, which is also used in terrestrial laser experiments to keep drones powered and flying for hours.

The project has been named PHILIP – an acronym for “Powering rovers by High-Intensity Laser Induction on Planets.”

“The rover would convert this laser light into electrical power using a modified version of a standard solar panel, with photodiodes on the sides of the panel keeping it locked onto the laser down to centimetre-scale accuracy,” said ESA.