The fuel saved by accurate orbital maneuvers may help prolong the working time of Chang'e-1, China's first lunar probe, by about one year, said a Chinese researcher on Tuesday.
"So far, orbital transfers of the probe have all been done accurately," said Bian Bingxiu, a researcher with the China Aerospace Science and Technology Corporation, following the probe's successful second braking.
Chang'e-1 completed its second braking and entered a 3.5-hour orbit with a perilune of 213 km and an apolune of 1,700 km at around 11:35 a.m. on Tuesday.
"The precise ground maneuvers and orbital transfers have saved a lot of fuel, which may prolong the probe's working time on its final orbit by around one year," Bian said.
Chang'e-1 is expected to brake for the third time to enter a 127-minute round polar circular orbit, where it was originally designed to stay a year for scientific explorations.
"In the prolonged period, the probe can carry out some other scientific tests, which may help acquire experience for China's second- and third-stage moon missions," Bian said.
The launch of Chang'e-1 kicks off the first step of China's three-stage moon mission, which will lead to a moon landing and launch of a moon rover at around 2012. In the third phase, another rover will land on the moon and return to earth with lunar soil and stone samples for scientific research at around 2017.
The Beijing Aerospace Control Center (BACC) cancelled two pre-set orbital corrections while the probe traveled along the earth-moon transfer orbit from Oct. 31 to Nov. 5, calling them "unnecessary" as Chang'e-1 had been running accurately on the expected trajectory.
So far, the satellite has experienced four orbital transfers, one orbital correction and two brakings. All these maneuvers usually consumed a great deal of fuel, scientists explained.
Because of the planned maneuvers, the fuel that the 2,300-kg Chang'e-1 carries accounts for nearly half of the satellite's total weight.
Chang'e-1 successfully completed its first braking and entered the moon's orbit at around 11:37 a.m. on Monday, which made it become a "real" circumlunar satellite.
The probe is expected to fulfill four scientific objectives, including a three-dimensional survey of the Moon's surface, analysis of the abundance and distribution of elements on lunar surface, an investigation of the characteristics of lunar regolith and the powdery soil layer on the surface, and an exploration of the circumstance between the earth and the moon.