- By Jonathan Amos
- Science reporter
Japan's space agency JAXA says Japan could save its moon landing site if the sun hits just the right spot.
The Slim spacecraft was powered down three hours after its historic moon landing to conserve power.
Engineers realized that its solar cells were facing west away from the sun and could not generate electricity.
But the mission team now hopes that the situation will improve as lighting conditions change.
“We believe that if sunlight hits the Moon from the west in the future, there is potential for power generation, and we are currently preparing for restoration,” the JAXA statement said.
The Slim mission — nicknamed the “Moon Sniper” for its use of precision landing technologies — made Japan the fifth country in history to complete a soft lunar touchdown.
But joy at seeing the craft complete its controlled descent turned to concern as power levels drained.
Instead of the system going completely flat, the decision was made to put the craft to sleep.
“According to our procedures the battery was disconnected, with 12% power remaining, to avoid a situation where the restart (of the lander) would be interrupted,” Jaksa said.
“As a result, the spacecraft was powered down at 02:57 (Saturday, Japan time or 17:57 GMT, Friday).”
Before the shutdown, Mission Control was able to successfully collect details of Slime's predicament, as well as images and data about its descent to the lunar surface.
“After making sure that a lot of data is received we start to relax and get excited,” Jaksa said.
The agency promised updates throughout the week.
Moon missions attempt to land early on a “lunar day” when the sun is on the eastern horizon. This gives a spacecraft about two “Earth weeks” of light before the sun sets in darkness for two weeks in the west.
It is now “morning” where the slime descends on the slopes of Shioli Crater. As suspected, if the spacecraft's solar cells head west, the cells will have to wait until “lunar afternoon” before they catch enough light to begin charging the battery system.
Slim was carrying two small rovers and was able to eject as planned shortly before touchdown, the data indicated.
The craft is also equipped with an infrared camera to survey the local geology. It is uncertain how much investigation it will be able to do if power levels are restored.
Statistically, landing on the moon has proven to be very difficult. Only half of all attempts are successful.
Prior to Slim's touchdown, only the United States, the former Soviet Union, China, and India had made it to the surface intact.
A private American mission abandoned its landing attempt earlier this month after a propulsion malfunction occurred shortly after liftoff from Earth. Another commercial American mission will try its luck in late February.