China today successfully completed its first return mission to the moon with its unmanned orbiter landing back on Earth, becoming only the third country in the world to do so after the former Soviet Union and the US accomplished the feat about 40 years ago.
In the latest step forward for its ambitious space programme, the test lunar orbiter landed in Siziwang Banner of China’s Inner Mongolia Autonomous Region early this morning over a week after it was launched to test its ability to go to the lunar orbit and return to Earth.
Search teams recovered the orbiter at the designated landing area, about 500 kilometres away from Beijing, state- run Xinhua news agency reported.
The last documented mission of this kind was by the Soviet Union in the 1970s.
Launched Friday last week, the orbiter traversed 840,000 kilometres on its eight-day mission and took some incredible pictures of the Earth and moon together, the report said.
The re-entry process began at around 6:13 AM (local time) with the orbiter approaching Earth at a velocity of about 11.2 kilometres per second.
The high speed led to a lot of friction between the orbiter and air and high temperatures on the craft’s exterior, generating an ion sheath that cut off contact between ground command and the orbiter.
To help it slow down, the craft is designed to “bounce” off the edge of the atmosphere, before re-entering again.
The process has been compared to a stone skipping across water and can shorten the “braking distance” for the orbiter, said Zhou Jianliang, chief engineer with the Beijing Aerospace Command and Control Centre.
“Really, this is like braking a car. The faster you drive, the longer the distance you need to bring the car to a complete stop,” Zhou said.
The “bounce” was one of the biggest challenges of the mission because the craft must enter the atmosphere at a very precise angle.
An error of 0.2 degrees would have rendered the mission a failure, he said.
Wu Yanhua, vice director of China’s State Administration of Science, Technology and Industry for National Defence, said the successful test mission has gathered a lot of experimental data and laid a solid foundation for future missions.
The eight-day programme is a test run for the final chapter of China’s three-step — orbiting, landing and finally returning — lunar programme.
The orbiter obtained data and validating re-entry technology such as the heat shield and trajectory design for a future landing on the moon by Chang’e-5 to be launched around 2017.