No Initial Correction Needed

Chang'e I, China’s first lunar probe carried out its first orbital correction on the morning of November 2, to ensure it travels on its preset orbit, according to China Daily.

The Beijing Aerospace Control Center (BACC) issued the instructions at 10:25 am on Friday, November 2; when two small engines on Chang'e I were ignited to slightly modulate its trajectory.

Eight minutes later, the orbital correction was completed, according to BACC reports.

An earlier plan to adjust the orbit was canceled when the probe continued on its proper trajectory after leaving Earth’s orbit on October 31, according to BACC engineers, as reported by ANN.

"Data shows we have reached our expectation through the orbital correction," chief engineer Wang Yejun said. "That's also the reason why we didn't employ the main engine on Chang'e I for the first orbital correction, because it is not necessary and it also saves energy for the orbiter's future operation."

A second orbital correction might be carried out on Sunday, November 4, Wang said.

Orbital correction is necessary to prevent the probe from veering off its projected course, according to Pang Zhihao, a researcher with the China Academy of Space Technology.

"An aircraft faces many disturbances, such as gravitation from celestial bodies. When it travels in space, we have to carry out corrections to ensure it moves on the right track," Pang said.

"Just like driving a car, we must keep turning the steering wheel to ensure the car stays on the road," he said.

Chang'e I entered the Earth-moon transfer orbit on Wednesday and is expected to arrive at the lunar orbit at 11:25 am on November 5.

Once it becomes a real circumlunar satellite after being captured by lunar gravity, the satellite will relay its first pictures of the moon in late Novembe. It will then continue scientific explorations of the moon for a year further.

FMI: www.cnsa.gov.cn