China’s Chang’e-4 Lander/Rover On Its Way to the Lunar Farside

China launched its Chang’e-4 mission to the Moon today.  The lander and rover will be the first spacecraft to land on the Moon’s far side, which always faces away from Earth.  The landing is expected between January 1 and January 3, 2019.

This is China’s fourth probe in the Chang’e series and will be the second to land on the Moon.  Chang’e-1 and Chang’e-2 were orbiters.  China became the third country in the world — after the Soviet Union and the United States — to land on the Moon in 2013 with Chang’e-3 and its rover, Yutu.  Chang’e-4 was built as a backup to Chang’e-3 and also has a rover.

Chang’e is China’s mythological goddess of the Moon.  The Chang’e-3 rover was named Yutu after her pet Jade Rabbit.  A competition was held to name the Chang’e-4 rover, but China has not announced the winner yet.

Chang’e-4 will be the first spacecraft of any country to land on the farside.

The Moon is tidally locked with Earth, so one side always faces Earth and the other always faces outward.  Both sides experience periods of dark and light on a 14 day cycle, waxing and waning from Full Moon to New Moon.  The farside is often mistakenly referred to as the “dark” side, but the duration of darkness is the same as the nearside.

Because Chinese mission controllers cannot communicate directly with the lander and rover once they on the surface, China launched a communications relay satellite, Queqiao, earlier this year.  China is planning a lunar sample return mission next year, Chang’e-5.  In 2014, it launched a mission to test technologies for that mission that orbited the moon and returned its capsule to a safe landing back on Earth.  If those are counted, Chang’e-4 is China’s sixth lunar mission.

China’s official news sources CGTN and Xinhua did not provide live coverage of the launch and Xinhua confirmed it via Twitter well after the fact.

China’s Chang’e-4 lunar probe, launched in the early hours of Saturday, is expected to make the first-ever soft landing on the far side of the moon. Check out the tasks of the mission. https://t.co/t7nMGAj14O pic.twitter.com/I0fIf0350W

— China Xinhua News (@XHNews) December 7, 2018

Live video of the Long March 3B launch from China’s Xichang launch site was provided unofficially by an amateur group and shared on social media, however.

CGTN posted a story later confirming that liftoff was at 02:23 December 8 in China (1:23 pm December 7 Eastern Standard Time).

Andrew Jones closely follows the Chinese space program for gbtimes.com.  In an article for Smithsonian Magazine, he reports that the spacecraft will land in about three-four weeks, sometime between January 1 and January 3, 2019.

Among the instruments on the rover are cameras, a visible/near-infrared imaging spectrometer, and a ground-penetrating radar.  Several international payloads also are aboard including a Dutch low-frequency spectrometer, a Swedish advanced small analyzer to study the interaction between the solar wind and the lunar surface, and a German neutron dosimeter to measure radiation at the landing site.  It also carries a “lunar mini biosphere” — a tin with potato and arabidopsis seeds and silkworm eggs — designed by Chinese university students.

No U.S. experiments are included.  NASA is prohibited by law from bilateral cooperation with China unless certain conditions are met.

The plan is to land in the South Pole Aitken Basin, a site of considerable scientific interest.  It is the oldest, largest and deepest impact basin on the Moon.  It stretches across a quarter of the Moon and is 8 kilometers deep.  Instruments on U.S. and Indian spacecraft have confirmed that water ice exists in permanently shadowed craters at both of the Moon’s poles, deposited by impacts from comets and asteroids over eons and preserved in the darkest and coldest locations.

China’s lunar spacecraft, like those of all countries other than the United States, are robotic.

Only the United States has sent people to the Moon and is about to celebrate the 50th anniversary of Apollo 8.  It carried the first crew to orbit the Moon — Frank Borman, Jim Lovell and Bill Anders — launching on December 21, 1968.

Apollo 10 five months later also orbited the Moon.  Between 1969 and 1972, Apollo 11, 12, 14, 15, 16, and 17 landed two-person teams of astronauts on the lunar surface while a third astronaut remained in orbit. Apollo 13 intended to land a crew, but a spacecraft malfunction on the way to the Moon aborted that plan. They flew around the Moon without entering orbit and safely returned to Earth.