CHANG’E-5 SAMPLE RETURN

Chang’e-5, scheduled to launch in 2019, is China’s first lunar sample return mission. It will provide an opportunity to study new lunar samples in terrestrial laboratories for the first time since Luna 24. Geologists have solved numerous fundamental scientific issues in lunar science with samples returned by the Apollo and Luna missions. The returned samples initiated a golden age of lunar research that continues to this day, as newly developed laboratory techniques allow scientists to perform new science on old samples. However, most of the Moon remains unexplored, and there are still many scientific questions that could be answered with new rocks and soil from the Moon.

Chang’e-5 will launch a large spacecraft stack including an orbiter with a re-entry capsule and a lander. The lander has no rover; instead, it has an arm to grab from the surface and a drill that can sample from a depth of 2 meters. The lander will have cameras and ground-penetrating radar similar to those on Chang’e-3 and 4, plus a lunar mineralogical spectrometer that can take spectra in the visible to infrared range. The spacecraft will collect up to 2 kilograms (4 pounds) of samples, placing them into an ascending craft that will rendezvous with the orbiter and transfer the samples to the re-entry capsule. The orbiter will return the capsule to Earth.

The Chang’e-5 lander is set to land in the Rümker region in northern Oceanus Procellarum (41-45° N, 49-69° W). The Rümker region remains unexplored by robotic or human landing missions carried out earlier by the United States (Surveyor, Apollo) and the Soviet Union (Luna), and no samples have ever been returned from this broad area. The region includes the Procellarum KREEP Terrane, a prominent geochemically anomalous area on the Moon. It is characterized by high concentrations of radiogenic heat-producing elements (such as thorium, uranium, and potassium) in a thin crust. It has also had much more recent volcanic activity than most of the rest of the Moon, the end of a long, complex geologic history. It may include some of the youngest material on the Moon. (For the Moon, “young” means younger than 3 billion years old.)