What is the purpose of launching Chang 'e II?

Experts from China Aerospace Science and Technology Corporation said that the implementation of the lunar exploration project is of great significance in terms of economy, science and technology and national development strategy. The implementation of the lunar exploration project will prepare for the development and utilization of lunar resources by mankind. The achievements of human exploration of the moon show that the unique energy and minerals on the moon are important supplements and reserves of earth resources.

The implementation of the lunar exploration project will promote the sustainable development of China's economy. The progress of basic science and high technology driven by China's lunar exploration project will bring traction and impetus to economic development.

Chang 'e II, which plays a key role in the lunar exploration project, will achieve six technological innovations and breakthroughs:

-Breaking through the launching technology of sending satellites directly into the Earth-Moon transfer orbit with launch vehicles. Compared with Chang 'e-1, which was launched into the near-earth transition orbit first and then adjusted several times by itself, Chang 'e-2 satellite will be directly sent into the lunar orbit with a perigee of 200 kilometers and an apogee of about 380,000 kilometers by a launch vehicle. It took nearly 14 days for "Chang 'e I" to enter the working orbit, and "Chang 'e II" could be completed within 7 days. Therefore, the "Chang 'e II" mission requires the launch vehicle to have greater thrust, higher orbit entry and control accuracy.

-Conduct X-band deep space TT&C technology experiments and preliminarily verify the deep space TT&C system. The flight TT&C of Chang 'e II mission will verify the X-band TT&C system newly built in China for the first time. Compared with the S-band satellite TT&C network used in Chang 'e-1 mission, the X-band radio transmission signal frequency is higher and the long-distance TT&C communication effect is better.

-Verification of100km lunar orbit capture technology. "Chang 'e I" was captured by the moon at a distance of 200 kilometers from the lunar surface, and "Chang 'e II" will be braked at a distance of 100 kilometers from the lunar surface, with faster flight speed, lower orbit and greater braking capacity. At the same time, the perturbation effect of the moon's uneven gravity field on the satellite orbit also increases correspondingly, which greatly improves the requirements for satellite braking control accuracy.

—— Verification of 100 km× 15 km orbit maneuver and rapid orbit determination technology. Chang 'e II will verify the orbital maneuver and rapid orbit determination technology of 100 km× 15 km, and test the ability to adjust the flight orbit from the circular orbit of 100 km to the elliptical orbit of the distant moon 100 km and the near moon 15 km.

-Test a brand-new floor camera, and the data transmission capacity is greatly improved. "Chang 'e II" added a landing camera to test its imaging ability to the moon and prepare for the soft landing of "Chang 'e III" on the lunar surface. The data transmission rate has also increased from 3 megabits per second of Chang 'e-1 to 6 megabits per second, and the propagation rate of 12 megabits per second will be tested.

-Conduct high-resolution imaging test on the pre-selected landing zone of Chang 'e III. Chang 'e II will conduct imaging tests on the pre-selected landing zone of Chang 'e III at the near moon points of circular orbit 100 km and circular orbit 100 km×15 km respectively, and the resolution is better than 10 m and 1.5 m. ..