HELSINKI — China could look to laser power transmission from lunar orbit to supply spacecraft on the moon and solve one of the big challenges for its lunar exploration plans.
Researchers have assessed the viability of using laser wireless power transmission (LWPT) from lunar orbiters to supply spacecraft left in the dark during the long, dark nighttimes on the surface of the moon. LWPT uses laser beams to transmit power wirelessly from orbiting satellites to surface receivers, converting light into electricity. The researchers recommend the development of key technologies, followed by on-orbit testing.
The moon being tidally locked to Earth results in extreme environmental conditions, with 14-day-long periods of darkness and extreme temperature fluctuations. While solar power can provide energy for spacecraft during the lunar days, the long nights bring challenges. Spacecraft typically need heat and a level of power to survive complete darkness and temperatures as low as -200 degrees Celsius (-328 degrees Fahrenheit).
As well as providing power during lunar nighttimes, LWPT could also support spacecraft operations in permanently shadowed craters, thought to hold water-ice, which can be used to make propellant or water or oxygen for astronauts.
Solutions such as radioisotope power sources are limited in power output and costly. Nuclear reactors, meanwhile, are ideal for large-scale bases, but bring concerns in the shape of safety and complexity.
LWPT is thus seen as a solution to some of the energy challenges faced during lunar exploration, offering flexibility and scalability in vacuum conditions, according to a paper published in the Journal of Deep Space Exploration (JDSE) in October 2024.
However, challenges such as efficiency, transmission ranges, visibility and operational challenges stand in the way of effectively utilizing LWPT.
“It is necessary to focus on the development of space high-power lasers and high-precision laser emission systems, and on-orbit technology verification should be carried out as soon as possible,” the authors conclude.
The paper was produced by authors from institutes including the China Academy of Space Technology (CAST) and Shandong Aerospace Electronics Technology Research Institute. The paper assesses various orbits to determine the optimum solutions for supplying areas such as equatorial regions and the poles.
NASA and the European Space Agency (ESA) have made earlier studies into supplying spacecraft on planetary surfaces using lasers in the 1990s and 2000s.
LWPT could support China’s ILRS
LWPT could be very useful to China as it expands its lunar exploration ambitions. The country is planning the construction of a moon base, known as the International Lunar Research Station (ILRS). Precursor missions, Chang’e-7 and Chang’e-8, are due to launch in 2026 and 2028 respectively. The multi-spacecraft missions will land at the lunar south pole, assessing the availability of resources and seeking out water-ice in shadowed craters, as well as testing in-situ resource utilization (ISRU) technologies. Last year China completed the first sample return mission from the lunar far side with Chang’e-6.
The ILRS will be constructed in the 2030s using a super heavy-lift launch vehicle to establish power, communications and other infrastructure at the chosen site. “Energy supply will become one of the core technical issues in lunar exploration and lunar resource development and utilization,” the authors of the paper assert.
Developing systems such as LWPT could provide China with solutions to key challenges to sustainable lunar exploration and provide a level of leadership in this arena.
Meanwhile, China is also researching the possibilities of space-based solar power. That project envisions generating power in geostationary orbit and beaming it to Earth. The country plans to use its Tiangong space station to test key technologies required for space-based polar power. China is also researching challenges of developing kilometer-scale ultra-large spacecraft needed for the project.
