China Launches World’s 1st Ever Mission to Land on the Far Side of the Moon

Throughout the twentieth and twenty-first centuries, we have sent hundreds of space probes to the moon to study it from afar. On December 8th, 2018, at 02:23, China sent spacecraft Chang’e-4, from the Long March 3B launch vehicle, towards the far side of the moon for a historical mission. This mission is set to land a lander and rover on the moon and explore a large basin on the far side. The landing is planned to take place during the first days of January 2019, after a 5-day voyage to the moon; however, no exact date has been released yet.

Chang’e-4 was launched by the China Aerospace Science and Technology Corporation (CASC), the main contractor for China’s space program. The launch was considered a success less than an hour after liftoff. The landing and exploration are expected to be in the Von Kármán Crater, a 186 kilometer wide hole located in a basin spanning 2500 km from rim to rim. Unfortunately, due to the crater being at the far side of the moon, away from Earth, any transmissions will be blocked by the moon. To overcome this hurdle, China also launched a satellite called Queqiao in May of this year. Queqiao will be located at a gravitationally stable area above the moon and relay communications between the rover and Earth. Communication is important for any data and discoveries found by Chang’e-4’s instruments. The mission also includes two microsatellites, Longjiang 1 and 2. While Longjiang 1 failed to enter orbit, Longjiang 2 successfully entered lunar orbit to observe and study phenomena in the moon’s sky.

Chang’e-4 is China’s fourth out of a predicted 7 missions of its Chinese Lunar Exploration Program. Chang’e missions 1 and 2 were a part of Phase 1 of the Exploration Program and served to overview the surface of the moon and make scans of it to prepare for landings in later phases. Phase 2 involves sending lunar landers to the surface and making observations there, something accomplished by the Chang’e-3 mission after landing on the moon in December of 2013. Chang’e-4 is also part of Phase 2, however it has set out to perform something not yet done by any national space program: land on and explore the dark side of the moon.

On Chang’e 4, there are eight scientific instruments to collect data. On the lander, there is the Landing Camera (LCAM), the Terrain Camera (TCAM), Frequency Spectrometer (LFS), and the Lunar Lander Neutrons and Dosimetry (LND). On the rover, there is the Panoramic Camera (PCAM), the Visible and Near-Infrared Imaging Spectrometer (VNIS), the Lunar Penetrating Radar (LPR), and the Advanced Small Analyzer for Neutrals (ASAN). All these instruments will be able to collect massive amounts of data about the surroundings and other characteristics of the far side of the moon in great detail.

In addition to instruments, the spacecraft also carries a small tin with silkworm eggs, seeds of tomato plants, and seeds of Arabidopsis plants (thale cress). These are to be used as part of a biology experiment in a small biosphere to test plant photosynthesis and cellular respiration in low-gravity and high-radiation environments on the lunar surface.

The mission also will attempt to investigate the mysterious Aitken Basin, located close to the south pole. The Basin is a result of an ancient impact on the planet, and this impact is thought to have disturbed the moon’s mantle, displacing some of it to the surface. A rover taking samples of this displaced mantle can provide greater insight into the interior of the moon than ever before. However, the mission’s main scientific work mostly revolves around measuring surface temperature over time, looking at the composition of the moon’s soil and rocks, and performing studies of cosmic rays and low-radio astronomical observation.

The Chang’e series of missions are named after the Chinese goddess of the moon. The remainder of the Chang’e missions, numbers 5 and 6, plan to return physical lunar samples to the Earth. However, the final plan for the Chang’e missions is to conduct a manned expedition to the south pole and to potentially set up an outpost on the Moon. This is planned for the 2030s.

If all goes well, this mission could be one remembered for centuries. This mission could teach us about the past and present of the moon, as well as teaching us about what makes the far side, or “dark side”, so different from the near side. Understanding this, we can advance our knowledge about the universe and make even greater discoveries in the future.