Chinese Lunar mission Chang’e 5
On 24 Nov 20, 0430 CST The Chinese launched their spacecraft Chang’e 5 from Wennchang, Hainan,….Their Long March rocket with 8.2-ton payload. The spacecraft entered into orbit around the moon on 28 Nov 20 and released the lander the next day. On 01 Dec 20 the lander left the lunar orbit to drop out for the long-awaited descent to the lunar surface. It made a soft landing at Mons Rümker region of Oceanus Procellarum at the south pole of the moon on 01 Dec 20 (sunrise 27 Nov, Sunset 11 Dec).
If one can believe Chinese Space agency, in a few minutes of their landing on moon, their surface explorer came out of the lander. They claimed that a robot arm equipped with a percussive drill & scoop excavated the lunar surface to pick up ~2 kg of loose rocks and soil from 2-meter depth. The robotic arm then transferred the collected samples in to the ascent vehicle, which separated from the lander on 03 Dec 20 to ascend back in to the lunar orbit in 6 min or so. They claim that the ascender docked with their Orbiter on 05 Dec 20 and transferred the sample-capsule in to the orbiter which was to return back to earth. They also claim that after the transfer of the sample, the ascender was made to decouple from the orbiter on 06 Dec 20, deorbit on 07 Dec 20 and crashed on to the lunar surface.
On 13 Dec the orbiter in lunar orbit fired all four of its 150 N engines 230 km above the moon surface for 22 minutes to enter the Moon-Earth Hohmann Transfer orbit. On the next day, the spacecraft is reported to have undergone minor course correction when the orbiter-returner fired two of the engines in order to tweak its direction in the transfer orbit. With these manoeuvres the craft should have entered the earth orbit. However, the Chinese report that the craft underwent further course correction on 16 Dec 20. The spacecraft should have made re-entry to earth’s atmosphere on 16 Dec 20 to land at a site in Siziwang Banner of north China's Inner Mongolia. However, it made it landing in the early hours (1:59 local time) of 17 Dec 20 duly tracked by the authorities.The picture opposite shows the IR image and the subsequent retrieval of the capsule from its landing spot.
The European Space Agency supported the Chang'e 5 Mission by providing tracking via ESA's Kourou station, located in French Guiana. ESA tracked the spacecraft during the launch and landing phases while providing on-call backup for China's ground stations throughout the mission. Data from the Kourou station helped the mission control team at the Beijing Aerospace Control Centre to determine the spacecraft's health and orbit status. During the landing phase, ESA used its Maspalomas station, located in the Canary Islands and operated by the Instituto Nacional de Tecnica Aerospacial (INTA) in Spain, to support the tracking efforts in its Deep Space Networks as placed opposite. It shows various trajectories of the Chang’e 5 from and to the Earth in brief.
Hopefully the capsule really has moon rocks and if so, it is the first time scientists have obtained fresh samples of lunar rocks since the Soviet Union’s Luna-24 probe, to bring back 170 grams (6 ounces) of samples in 1976 from a region called Mare Crisium. US astronauts brought back 842 pounds (382 kilograms) of lunar samples from 1969 to 1972, some of which are still being analysed and experimented upon.
Despite the doubts expressed by many of the international communities on the Chang’e 5 Lunar mission amidst the secrecy observed by the Chinese space agency, the unmanned mission bringing the lunar sample is praiseworthy. It speaks of volumes of their lander’s soft landing, digging the rocky surface 2-meter deep, collecting samples and transferring it to the ascender must have been challenging. Even more challenging would have been the lifting-off of the ascender module to join the precise orbit of their Orbiter, docking with it followed by rendezvous of transferring the lunar sample within the capsule of the Orbiter and dropping the ascender back to the lunar surface. The subsequent events too must have been challenging in the Orbiter setting the course for earth, re-entry to atmosphere and landing at the pre-set area…all are praiseworthy. All scientists involved with the mission must be applauded for their efforts. Undoubtedly, China writes a new chapter in unmanned deep space manipulations and ventures.