Moon lander hits target, looks to be upside-down
TOKYO – Japan's space agency said Thursday that its first lunar mission hit the tiny patch of the moon's surface it was aiming for, in a successful demonstration of its pinpoint landing system – although the probe appears to be lying upside-down.
Japan became the fifth country in history to reach the moon when the Smart Lander for Investigating Moon, or SLIM, touched down on the moon early on Saturday. But trouble with the probe's solar batteries made it hard at first to figure whether the probe landed in the target zone.
While most previous probes have used landing zones about 6 miles wide, SLIM was aiming at a target of just 330 feet. Improved accuracy would give scientists access to more of the moon, since probes could be placed nearer to obstacles.
One of the lander's main engines lost thrust about 54 yards above the moon surface, causing a harder landing than planned.
A pair of autonomous probes released by SLIM before touchdown sent back images of the box-shaped vehicle on the surface, although it appeared to be upside down.
After a few days of data analysis, the Japan Aerospace Exploration Agency, or JAXA, determined that the spacecraft landed about 60 yards away from its target, in between two craters near the Shioli crater, a region covered in volcanic rock.
But after the landing mishap, the craft's solar panels wound up facing the wrong direction, and it cannot generate power. Officials said there is still hope the probe will be able to recharge when the moon enters its daytime in the coming days.
JAXA project manager Shinichiro Sakai said the images sent back were just like those he'd imagined and seen in computer renderings.
“Something we designed traveled all the way to the moon and took that snapshot. I almost fell down when I saw it,” he said. For the pinpoint landing, Sakai said, he would give SLIM a “perfect score.”
“We demonstrated that we can land where we want,” Sakai said. “We opened a door to a new era.”
LEV-1, a hopping robot equipped with an antenna and a camera, was tasked with recording SLIM's landing and transmitting images back to earth. LEV-2 is a baseball-sized rover equipped with two cameras, developed by JAXA together with Sony, toymaker Tomy Co. and Doshisha University.
The two autonomous probes frame and select images independently, both using LEV-1's antenna to send them back to base.
Daichi Hirano, a JAXA scientist who designed LEV-2, said it selected images containing SLIM and nearby lunar surface and transmitted the images through LEV-1, making the pair the world's first to achieve the mission. Despite the rush, the probes captured and transmitted 275 images.
Japan followed the United States, the Soviet Union, China and India in reaching the moon's surface.
The project was the fruit of two decades of work on precision technology by JAXA.
JAXA has a track record with difficult landings.