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 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.
Credit: spacenews.com