About 40 years late to the "Space Race", this morning Saturday Nov. 1, 2014, China became the third nation in the world to successfully orbit the moon and return to Earth to tell the tale. As China's space agency continues to move forward in its ambitious space program, the lunar orbiter marks a great first success for the mission, and undoubtedly shows its growing presence as a space agency in the world. The eight day turn-around trip came to a close this morning after the test lunar orbiter landed about 500 km away from Beijing, in the Siziwang Banner of China's Inner Mongolia Autonomous Region according to the nation's Xinhua state-run news agency.
Launched last Friday, the orbiter made an 840,000 km voyage and photographed the momentous occasion, which has not been done since the Soviet Union of Russia accomplished the task in the 1970's. Reentering the outer atmosphere at 6:13am, at a speed of 11.2 km per second, the orbiter is designed to slow down after first contact with the atmosphere by "bouncing" off the edge before reentry. However, reentry with the orbiter did not go exactly to plan.
Continuing at a high speed velocity, friction between the orbiter and air upon reentry led to high temperature on the spacecraft's exterior causing an ion sheath that disrupted communication between the orbiter and ground command. However, reentry was successful even with an elongated braking distance for the orbiter chief engineer with the Beijing Aerospace Command and Control Center, Zhou Jianliang says.
"Really, this is like braking a car" Jianliang says. "The faster you drive, the longer the distance you need to bring the car to a complete stop."
And the unlikely success in reentry came at a rather small window of error. With a precise angle of reentry needed, any error greater than a 0.2 degree change would have rendered the mission a failure. But the eight day test-run successfully returned, prompting China to look towards future missions already in stages of development.
In 2017, China will send a lander designed by Chang'e-5 to collect data and samples of the Moon's surface to return to Earth. And while China now knows that the trip has a large margin for success, data collected from this preliminary orbiter trip will help to validate and guide re-entry technology, as well as the trajectory design for future missions.
