Spacecraft tests to pave the way for vital lunar mission

An experimental spacecraft will be launched before 2015 to conduct crucial re-entry tests on the capsule to be used in the Chang'e-5 lunar-sample mission, a leading space program official said.

Chang'e-5 is expected to be China's first lunar explorer to return to Earth. The mission will be carried out before 2020.

The experimental spacecraft will consist of the Chang'e-2 lunar orbiter base structure as well as the return capsule that will be used by the Chang'e-5, said Hu Hao, chief designer of the lunar exploration program's third phase and a deputy to the National People's Congress.

"Scientists believe we need to launch the spacecraft to prove that our current technical plan can actually bring Chang'e-5 home safely," Hu told China Daily on the sidelines of the NPC annual session.

He explained that when the Chang'e-5 returns to Earth with samples of lunar soil, the capsule will be hurtling through Earth's atmosphere at, or close to, speeds of 11.2 km per second.

"The re-entry speed means the return capsule could overheat or prove difficult to track and control," he said.

None of China's spacecraft have ever re-entered the atmosphere so fast and no simulation test can recreate the challenge, he said.

"The Chang'e-5 mission will enter the prototype phase this year," he said. The mission involves a "relay" approach that requires precision rendezvous and docking in lunar orbit.

After launch, the Chang'e-5 will head straight for lunar orbit. Two modules will separate and land on the moon, with one collecting soil samples.

The samples will be placed in the ascending module that will blast off from the lunar surface and dock with the orbiting module. The sample will then be transferred from this module to one that will be used for re-entry.

Yan Jun, head of the National Astronomical Observatories of the Chinese Academy of Sciences and chief scientist of the lunar exploration program, said some of the soil will be scooped up from the surface, but some will be taken from a depth of 2 meters.

The three-step lunar exploration program features "circle, land and return".

China has launched two lunar probes, Chang'e-1 and 2, both having circled the moon. Chang'e-3 will blast off in the second half of this year to become the country's first lunar explorer to soft land on the moon.

Contact the writer at xindingding@chinadaily.com.cn