On 3rd of January, China’s rover Chang’e 4 landed on the lunar surface. This was the first time humans have landed anything on the so called dark side of the Moon – it’s not really dark. The spacecraft was launched on 8th of December, last year, on a Long March 3B rocket with the destination being the South Pole region and the Aitken Basin. Part of the reason to go to the far side of the Moon is that it is naturally shielded from the electromagnetically noisey Earth, because of us. There’s also a number of questions about the nature of the Moon on the other side and plenty of exploration opportunities near the South Pole, so a good spot to send a rover that will contribute greatly to our understanding. The whole spacecraft weighed in at about 3780kg with the lander being around 1200kg and the much smaller rover at 140kg. Once the lander had made it to the surface of the Moon it snapped the below picture before the rover drove off the lander along some tracks.
The science payload on the rover and the lander is quite complex, as you would expect the opportunity to pack the spacecraft with sensors was taken up. The rover has three instruments including a panchromatic camera, a radar to examine the lunar surface and a spectrometer to analyse lunar material. The aim of the rover is to drive around and poke at the surface to get an understanding of the surface material. The rover mission is supposed to last about three months. The much large lander has a range of instrument beyond the usual cameras to examine the radiation environment on the Moon. There are also a couple of instruments, both on the lander and rover, jointly developed by China and Germany. The international cooperation on the mission is quite heartening and shows an increasing collaborative approach by China in space missions.
Back in May last year, the Chinese also launched a communications satellite to support missions to the Moon. They launched the 425kg Queqiao spacecraft into the L2 point which sits just beyond the Moon at about 65,000 kilometres. The Queqiao is used a a relay for the Chang’e 4 lander and rover and is the first time the L2 point has been used for this purpose. There’s quite a lot that goes into supporting this sort of mission and the added complexity of operating from the far side of the Moon brings an additional layer of required support. The communications satellite also has a joint Dutch/Chinese payload that specifically takes advantage of the lower noise on the far side of the Moon by examining radio emissions from deep space.
The mission also includes a small capsule that contains organic material including plants and silkworms eggs. The aim being to see if the silk worms can survive and grow and that the plants can support them. All of this is contained in a sealed capsule with cameras so scientists can observe what’s going on. The Moon is a very inhospitable place, which does not harbour live is bathed in radiation and it ha no atmosphere, so the chances of the Moon being contaminated by the organic material on Chang’e 4 are almost non existent and even if that would happen it wouldn’t be relevant. According to the NASA’s Office of Planetary Protection, none of the more than 2,000 samples of lunar material brought back to Earth by six Apollo missions has yielded any evidence of past or present lunar biological activity. Thus, the current scientific consensus is that the potential for indigenous life on the Moon is negligible, and that forward and back contamination resulting from lunar exploration are not concerns.
Overall a very ambitious and complex mission involving two launches, including the communication satellite launched in May. The mission follows other successful launches including the very popular Yutu rover from Chang’e 3. The next plan is to send a sample return mission and no doubt with the current success of Chang’e 4 this mission will also yield some promising results. It’s great to see some fresh images form the Lunar Surface and with plethora of lunar plans out we should see some more in the coming years from a variety of missions.