China's lunar rover seen in images from the moon
BY STEPHEN CLARK
Posted: December 16, 2013
China's robotic lunar lander sent back its first sharp images on Sunday, showing the six-wheeled Yutu rover a day after driving off its landing platform to begin a three-month sojourn across the moon's barren soils.
The rover disconnected from the landing platform beginning about six hours after touchdown, severing electrical and mechanical connections before sliding off the lander on a ramp and driving on to the moon's surface.
One of the lander's cameras beamed low frame-rate video of the rover's first drive back to Earth on Saturday, but Sunday's pictures -- carefully choreographed in preflight planning -- showed more detail as the two vehicles were positioned about 30 feet apart.
A report on Chinese state television said the rover would drive around the lander and take more photos of the other side of the craft, which appeared to come down on a relatively flat plain.
An image from the rover's panoramic camera showed the lander's four legs resting on the lunar surface and solar panels extended to charge the probe's batteries.
And photos of the rover taken by the Chang'e 3 lander showed the mobile robot's tracks entrenched on the moon's immutable soil. The rover appeared to drive away from the stationary Chang'e 3 mothership and perform a 180-degree turn to face the lander for Sunday's picture-taking session.
China named the rover Yutu after soliciting suggestions from the public. Yutu translates as "Jade Rabbit" in English.
In Chinese mythology, Yutu is a rabbit who accompanies the goddess Chang'e to the moon.
With the receipt of Sunday's images, China declared the Chang'e 3 mission -- conceived as an engineering and technology demonstation -- a complete success.
"The moon rover and lander have completed the task of taking photos of each other. Data transmission was normal and complete, and images received were clear. The moon rover and lander are currently in a stable condition. I now declare the Chang'e 3 mission a complete success," said Ma Xingrui, chief commander of China's lunar program, according to the state-run Xinhua news agency.
But the rover still has much to do. It is designed for a three-month mission, and the Chang'e 3 lander could operate more than a year.
The rover's ground-penetrating radar, which will resolve subsurface geological structures to a depth of 100 meters, or nearly 330 feet, is already activated. The Yutu robot also carries a panoramic camera, which is also switched on, and X-ray and near-infrared spectrometers to measure the composition of rocks and soil.
The stationary landing platform will perform imaging tasks over the next few months. It has an ultraviolet telescope to observe Earth's plasmasphere and conduct the first long-term astronomical observations from the lunar surface, according to China.
Chinese officials have not announced where the rover will drive after finishing up its photography around the lander. The rover stands nearly 4 feet tall and has a mass of 140 kilograms, or 308 pounds.
Space enthusiasts posting on the website unmannedspaceflight.com analyzed early imagery from the Chang'e 3 lander and concluded it likely touched down less than 50 feet south of a small crater rimmed by rocky outcrops.
The rover initially drove in the direction of the crater for Sunday's photo session, but it was expected to move in a different direction as it imaged the lander from other angles.
An analysis of the landing by Mark Robinson, a scientist at Arizona State University, shows Chang'e 3 also landed just east of a much larger crater.
"By correlating features seen in the nested series of Chang'e 3 descent images it appears the spacecraft landed just to the east of a 450 meter (1476 feet) diameter crater," Robinson posted in a blog.
Robinson is the principal investigator for the Lunar Reconnaissance Orbiter Camera, or LROC, on a NASA spacecraft that has mapped the moon since 2009.
"LRO will next be above western Mare Imbrium on 24 and 25 December, and LROC will image the Chang'e 3 landing site," Robinson wrote Sunday.
Paul Spudis, a planetary geologist at the Lunar and Planetary Institute in Houston, wrote a blog post for Air & Space Magazine describing the landing site's scientific potential.
Mare Imbrium contains unique titanium-rich lunar lava flows that have not been thoroughly explored, according to Spudis.
"Thus we are poised to investigate a new site on the moon of considerable interest and complexity, one that displays a variety of geological units and processes," Spudis wrote. "The Chang'e 3 lander and Yutu rover can provide many answers to our questions regarding the geological history of this region of the moon and about lunar history in general."
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