China launches historic mission to land on far side of the moon - Spaceflight Now

A view of the far side of the moon and the distant Earth, captured by the service module for the Chang’e 5-T1 tech demo mission in 2014. Credit: Chinese Academy of Sciences

A robotic lander and rover lifted off Friday (U.S. time) from China’s Xichang space center, kicking off a journey through space that will culminate in an attempt in early January to touch down on the far side of the moon for the first time.

The Chang’e 4 mission — the fourth in China’s main line of lunar explorers — lifted off at around 1823 GMT (1:23 p.m. EST) Friday from Xichang, an inland spaceport nestled between hills in southwestern China’s Sichuan province.

Chang’e 4 climbed into the night sky at Xichang — liftoff occurred at 2:23 a.m. Beijing time Saturday — toward the east affixed to the top of a Long March 3B rocket.

Chinese state television did not broadcast the launch live, as it did for China’s previous lunar mission launch in 2013, but spectators near Xichang streamed live video of the middle-of-the-night blastoff online without commentary. The video showed the Long March 3B disappearing into the night sky a few minutes after an apparently smooth liftoff from Xichang.

The three-stage Long March 3B rocket was programmed to inject the Chang’e 4 spacecraft on a trajectory toward the moon less than a half-hour after liftoff.

Chang’e 4 is expected to enter lunar orbit later this month, then use braking rockets to descend to the moon’s surface, targeting a landing in Von Karman crater in moon’s South Pole-Aitken basin region in early January.

No mission has explored the surface of the far side of the moon before, and if successful, Chang’e 4 will be a major first in space exploration, reaching a destination that has long been on the to-do list for NASA and international space scientists.

Chang’e 4 uses spare hardware built for China’s Chang’e 3 lunar lander and rover, which arrived at the moon in December 2013 with a touchdown in the Mare Imbrium volcanic basin on the near side of the moon.

The rover ceased driving a few weeks after landing, but some of the craft’s instruments continue functioning. The Chang’e 3 rover, named Yutu and designed to drive up to 6 miles (10 kilometers), traveled around 374 feet (114 meters) before losing its mobility, according to Chinese scientists.

“There are plenty of successful missions with successful landings on the near side of the moon, including Chang’e 3 in Mare Imbrium,” said Jun Huang from the Planetary Science Institute at the China University of Geosciences, in a presentation to U.S. scientists in March at the Lunar and Planetary Science Conference in Texas. “This mission has lasted for nearly five years, and it increased our knowledge about the moon greatly, however, we don’t have (until Chang’e 4) a mission dedicated to taking precision mesurements of the far side of the moon.”

There are some key differences between Chang’e 3 and Chang’e 4. For example, the lander heading for the far side of the moon will not carry a robotic arm or an Active Particle X-ray Spectrometer, an instrument capable to measuring the chemical elements in lunar rocks and soil.

In addition to a suite of cameras on both the stationary lander and rover, the mission aims to deliver a new set of sensors to the lunar surface, some of which are provided by European scientists.

The landing module, which will make a rocket-powered landing on the moon like Chang’e 3, will carry a low frequency radio spectrometer developed by Chinese scientists for astrophysics research. A German-developed neutron and dosimetry instrument will measure radiation levels at the Chang’e 4 landing site, collecting data that could be useful in planning human exploration of the lunar far side, studying solar activity, and gauging the underground water content in Von Karman crater.

The Chang’e 4 rover will host a ground-penetrating radar to study geologic layers buried under the landing site, and a visible and near-infrared spectrometer to gather data on soil composition. Chinese officials approved the addition of a Swedish instrument to study the interaction between the solar wind and the lunar surface, which is not shielded by an atmosphere from the bombardment of charged particles originating at the sun.

Chang’e 4 will also deliver to the moon a student-designed carrier containing potato seeds and silkworm eggs. University students and scientists will monitor the growth of the organisms, which will be housed inside a chamber and fed natural light and nutrients once on the lunar surface.

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Follow Stephen Clark on Twitter: @StephenClark1.