#Launch #Change #probe #bring #samples #side #Moon
The Chinese space program returns to the Moon with the launch of Chang’e 6, the first probe that must bring samples of the hidden side of our satellite to Earth. On May 3, 2024 at 09:27 UTC, the CZ-5 Y8 Long March rocket successfully took off from the LC-101 ramp of the Wenchang Space Center, on Hainan Island, with the Chang’e 6 (CE-) probe. 6, 嫦娥六号) on a complex 53-day mission. After two second stage burns, the probe was placed on a trajectory toward the Moon and separated about 37 minutes after takeoff. It is the 8th launch of a CZ-5 – a three-stage version of the most powerful Chinese rocket in service – and the 12th of a CZ-5 in general, including the two-stage CZ-5B, used for launches to low orbit. . It is also the third launch of a CZ-5 in just six months. Chang’e 6 is the second probe in the Chang’e family to use a CZ-5 heavy rocket and the third Chinese probe in total to use this launcher, including the Tianwen 1 Mars probe. Chang’e 6 carries the small Icube-Q satellite of the Pakistan space agency (SUPARCO), which will be deployed in lunar orbit. The mission’s launch window spanned three days, with each day lasting 50 minutes.
If everything goes as planned, Chang’e 6 will enter lunar orbit on May 8 and the surface segment will land on the far side in the South Pole-Aitken basin area (43º south, 154º west) on the next 2 June, becoming the fourth Chinese probe to land on the lunar surface. The capsule with the samples is scheduled to land in Inner Mongolia on June 25. Chang’e 6 is basically similar to the Chang’e 5 probe, launched on November 23, 2020 and which returned on December 16 of that same year with 1.73 kg of lunar samples from the Mons Rümker region in the visible face. In fact, Chang’e 6 was originally built as a backup for the Chang’e 5 mission, just as Chang’e 4 was once a backup for Chang’e 3 (speaking of Chang’e 4, This probe remains active on the far side since 2019 together with the Yutu 2 rover).
Chang’e 6 probe before launch (CNSA).
Mission emblem (CNSA).
Chang’e 6 landing zone (red box) on the far side (CNSA).
Chang’e 6 is a sample collection probe weighing about 8 tons and 7.2 meters high built by CAST (China Association for Science and Technology), a subdivision of CASC—the prime contractor for China’s space program—for China’s lunar exploration program, CLEP (Chinese Lunar Exploration Program). The probe is made up of two ships, each divided into two parts: the orbital segment and the surface segment. The surface segment, weighing 3.8 tons, includes a descent stage similar to the Chang’e 3 and Chang’e 4 probes on which the ascent stage is located. The orbital segment includes the 3.2-ton orbiter and the 1-ton return capsule.
The landing and orbital segment of Chang’e 6 (CNSA).
The four elements of Chang’e 6 (CNSA).
Elements of Chang’e 6 (CNSA).
Chang’e 6 configuration on the way to the Moon (CASC).
The architecture of the mission is similar to that of Chang’e 5 and, like this, it is the most complicated carried out by an automated mission. The orbital module will use its 3 kilonewton thrust YF-37 main engine to place the array into a preliminary elliptical lunar orbit with a period of 12 hours. It will then enter an orbit with a period of 4 hours before reaching a circular orbit of 200 kilometers. The surface segment will be separated from the orbital segment and placed into a 15 x 200 kilometer orbit. The descent module will carry out an automatic landing using the YF-36A 7.5 kilonewton engine of the descent stage and the autonomous navigation system using LIDAR and optical navigation. After collecting the samples, the container with the samples will be placed in the ascent stage.
Orbiter descent segment separation (CNSA).
Chang’e 6 orbits around the Moon (CNSA).
The surface descent segment (CNSA).
The stage will take off on June 4 using a 3 kilonewton thrust engine and will dock with the orbiter using an ingenious system (hooks on the orbiter will “hug” the three bars of the ascent stage). The descent stage will remain on the surface (it is assumed that it does not carry RTG like Chang’e 3 and 4, so, like the descent stage of Chang’e 5, it will not survive the lunar night). The container will then be moved from the ascent stage to the capsule, located inside the orbiter. After releasing the ascent stage in lunar orbit, the orbiter with the capsule will head towards Earth and on June 25 it will release the capsule, which will carry out a double re-entry —skip reentry— before landing using a parachute.
The surface segment includes a drill and a robotic arm for collecting samples (CASC).
Descent segment. In the foreground you can see the drill tube (CASC).
Takeoff of the ascent stage (CNSA).
Ascent stage (CASC).
Orbiter Ascent Stage Capture System on Chang’e 5 and 6 (CASC).
Elements of the orbiter (CASC).
Chang’e 6 will collect the samples using a drill and a robot arm. As in the case of the Chang’e 5, the drill will be able to collect regolith to a depth of about 2.5 meters (the Chang’e 5 could only drill up to one meter), while the robot arm will be used to collect, in addition to regolith, surface rocks. The amount expected to be collected has not been made public, but it is assumed to be between 2 and 3 kg.
Container with 1.7 kg of lunar samples from Chang’e 5 (CNSA).
The sample container has two cylinders: a large cylinder in which the rolled drill samples are accumulated and a smaller cylinder with the samples collected on the surface by the robot arm (CASC).
Drill detail: The samples are accumulated rolled in a cloth tube and then deposited in the cylinder (CASC).
Separation of the ascent stage in lunar orbit with the docking mechanism after transferring the samples to the capsule (CNSA).
Sample capsule on the orbiter (Chang’e 5) (CASC).
The main difference with the Chang’e 5 mission is that, upon landing on the far side, Chang’e 6 will not be able to communicate directly with Earth, so it will require the services of the relay satellite. Queqiao 2, launched on March 21 along with the small lunar satellites Tiandu 1 and 2 using a CZ-8. Queqiao 2 will retransmit data from Chang’e 6 from an ELF-type inclined lunar elliptical orbit (Elliptical Lunar Frozen Orbit), with a period of 24 hours and 200 x 16,000 kilometers, with an inclination of 62.4º. Queqiao 1, still in service at the L2 Lagrange point of the Earth-Moon system, from where it serves as a relay for Chang’e 4, will serve as a reserve for this mission.
Queqiao 2 (CNSA).
Cameras and instruments of the Chang’e 6 mission (CNSA).
In addition to several cameras and a deployable flag of the People’s Republic of China, Chang’e 6 carries three European scientific instruments: the French radon detector DORN (Detection of Outgassing RadoN), provided by the French space agency CNES and IRAP (Institute of Research in Astrophysics and Planetology), the Italian INRRI laser retroreflector (INstrument for landing-Roving laser Retroreflector Investigations), from the National Institute of Nuclear Physics of Italy, and the Swedish solar wind sensor NILS (Negative Ions on Lunar Surface), provided by the European Space Agency (ESA). Chang’e 6 also carries, and as a surprise, a small rover that appears to be a mobile camera to record the sample collection operations and the takeoff of the ascent stage.
Foreign instruments aboard Chang’e 6 (CNSA).
Italian laser retroreflector (CNSA).
Swedish NILS (Negative Ions on Lunar Surface) solar wind sensor, supplied by the European Space Agency (ESA).
French radon detector DORN (Detection of Outgassing RadoN), supplied by the French space agency CNES and IRAP (Institut de Recherche en Astrophysique et Planétologie)
Chang’e 6 is part of the fourth phase of the CLEP program, approved in 2021, and which includes the life extension of Chang’e 4 and the future Chang’e 7 surface probes (which should take off in 2026) and Chang’e 8 (2028). As a separate note, the secrecy that has surrounded this mission is striking, and this despite the fact that it is similar to Chang’e 5. The precise takeoff time was not communicated until the day before and only images of the probe were published once launched.
Comparison between Chang’e 5 and 6.
Detail of the small rover (mobile camera) of the Chang’e 6 (CNSA).
On the mission cap we see the logos of the Chinese lunar exploration program CLEP, the Chinese space agency CNSA, the French space agency CNES, ESA and the Pakistani space agency (SUPARCO) (CNSA).
Phases of the Chang’e 6 mission
- May 3: launch.
- May 8: entry into lunar orbit.
- June 1: Separation of the orbiter’s descent segment.
- June 2: landing on the far side of the descent segment.
- June 4: The ascent stage takes off from the surface with the samples.
- June 6: docking of the ascent stage with the orbiter and transfer of the samples to the capsule.
- June 20: The orbiter sets course for Earth.
- June 25: entry of the capsule with the lunar samples.
Mission phases (CNSA).
Pakistani lunar satellite Icube-Q (CNSA).
Pakistan’s Icube-Q (CNSA).
Launch phases
- T+0 s: take off.
- T+173 s: shutdown of the 4 kerolox accelerator blocks.
- T+176 s: separation of the 4 kerolox accelerator blocks.
- T+325 s: separation of the coping.
- T+484.8 s: shutdown of the cryogenic core stage.
- T+488.6 s: separation of the central stage.
- T+489 s: ignition of the second stage.
- T+738.4 s: first shutdown of the second stage.
- T+1725.3 s: second ignition of the second stage.
- T+2126.5 s: second shutdown of the second stage.
- T+2210.6 s: separation from Chang’e 6.
Transfer to the ramp:
The rocket on the ramp:
Takeoff:
