Chinese rover to launch to the moon on Sunday
BY STEPHEN CLARK
Posted: November 30, 2013
China is set to launch a robotic rover to the moon Sunday in a bid to become the first nation to accomplish a lunar landing since 1976.
The rover is China's third lunar mission, following a pair of orbiters that reconnoitered the moon after launching in 2007 and 2010.
Nicknamed Yutu, which means "jade rabbit" in Chinese, the rover will drive around the lunar surface for up to three months, collecting imagery, looking for natural resources and studying the moon's geology.
In Chinese mythology, Yutu is a rabbit who accompanies the goddess Chang'e to the moon. Continuing the naming theme of China's previous lunar spacecraft, the mission launching Sunday is named Chang'e 3.
If the lander succeeds, Chang'e 3 will be the first mission to make a soft landing on the moon since Russia's Luna 24 mission arrived in August 1976.
The Long March booster will lob the rover and lander on a course to reach the moon Dec. 6, where it will slide into orbit for a little more than a week to wait for an opportunity to descend toward the mission's landing site in a region named Bay of Rainbows, or Sinus Iridum, on the upper-left part of the moon as viewed from Earth.
Landing is scheduled for Dec. 14, according to the European Space Agency, which is helping China track and communicate with the probe during its mission.
Official Chinese media outlets have not disclosed the mission's timetable, other than the launch date.
But some details of the Chang'e 3 mission have trickled out in recent days, although much information about the project, including its cost and technical parameters, remain secret.
The lander carries a bipropellant rocket engine designed to adjust its power level and pivot to control the probe's descent from an altitude of 15 kilometers, or about 9 miles, according to China's state-run Xinhua news agency.
The probe is equipped with terrain recognition sensors to feed data into the lander's computer, which can autonomously guide the spacecraft to a flat landing zone clear of boulders, craters and steep inclines. That's a first for an unmanned mission, and all robotic landers up to now had to risk settling on to rock fields or other unwelcoming terrain, including NASA's Curiosity rover when it touched down on Mars.
The four-legged lander will hit the lunar surface at a speed of less than 8.5 mph, and each leg features a device similar to a shock absorber on a car to cushion the impact, according to a paper published in Science China by members of the mission's development team.
Some time after landing, the probe will deploy a ramp for the Yutu rover to drive on to the lunar surface to begin its exploration mission.
The rover has a mass of 140 kilograms, or about 308 pounds, and carries radioisotope heater units to keep the spacecraft warm during the two week-long lunar nights. The heaters are likely powered by small quantities of plutonium-238, the isotope of plutonium preferred for space missions, according to respected space researcher Dwayne Day, who discussed the rover's heaters in a story published in the Space Review.
The Yutu rover carries advanced radars to study the structure of the lunar crust at shallow depths along its path, and it is outfitted with spectrometers to detect the elements making up the moon's soil and rocks, said Pei Zhaoyu, a spokesperson for the Chang'e 3 mission, in a report by Xinhua.
Four navigation and panoramic cameras are mounted on the rover to return high-resolution images from the moon.
The mission also has an optical telescope for astronomical observations from the lunar surface, according to Pei.
China's lunar program is focused on robotic missions for now, with plans for an unmanned mission to return rock samples to Earth by 2020. China's military-run human space program is focused on development of a space station in Earth orbit around the same timeframe, but scientists have studied a manned lunar mission in the next decade.
Chang'e 3 will be China's first mission to test the technologies required for future lunar exploration.
China has installed new deep space tracking antennas comparable to the "world standard" and developed advanced autonomous guidance, navigation and control systems for Chang'e 3, according to Wu Zhijian, a spokesperson for China's State Administration of Science, Technology and Industry for National Defence, or SASTIND, which is managing the mission.
Follow Stephen Clark on Twitter: @StephenClark1.