Recently, the re-entry event of Tiangong-1 has become the focus of global attention. Earlier, the China Manned Space Engineering Office released information that it is expected to reenter the atmosphere on April 1st, Beijing time. The prediction of Tiangong-1’s fall point needs to measure the current position and status of Tiangong-1. Both the International Laser Ranging Debris Group and relevant Chinese agencies have organized capable laser stations to carry out high-precision laser pointer measurements.
According to the Tiangong No. 1 orbit forecast data provided by domestic professional forecasting agencies, the current orbit altitude is lower than 200 kilometers. The Shanghai Astronomical Observatory of the Chinese Academy of Sciences overcomes the problems of invisible target optics and fast running speed. Using the Laoshan 60 cm diameter satellite laser rangefinder, it successfully achieved the Tiangong-1 laser ranging on April 1, 03:53 Beijing time. In 6 minutes, more than 12,000 valid observations were obtained with a ranging accuracy of about 1 cm. This may be the last high-precision laser ranging before Tiangong-1 re-enters the atmosphere. This successful measurement provided important observation data for determining Tiangong-1’s on-orbit position measurement, on-orbit status and fall point prediction.
The realization of centimeter-level precision laser ranging has benefited from the lidar cooperation target developed by the Shanghai Astronomical Observatory. This is an important load for the implementation of lidar rendezvous and docking at Tiangong-1, which has played an important role in the multiple missions of space rendezvous and docking at Tiangong-1. .
This is the last high-precision laser pointer ranging before Tiangong-1 re-enters the atmosphere. The successful measurement provided important observation data for determining the orbital position, on-orbit status, and fall point prediction of Tiangong-1. It is an important load for the implementation of lidar rendezvous and docking at Tiangong-1, which has played an important role in the multiple space rendezvous and docking missions at Tiangong-1. It was not expected that it will play its residual heat again in the precision laser orbit before Tiangong-1 reenters the atmosphere. The perfect curtain call of Tiangong-1 provided important orbital measurement data.