[meteorite-list] Chinese Probe Returns from Flight Around the Moon (Chang'e 5)

[Ron Baalke]

http://spaceflightnow.com/2014/11/01/chinese-pathfinder-probe-returns-from-flight-around-the-moon/

Chinese probe returns from flight around the moon
Stephen Clark
Spaceflight Now
November 1, 2014 

Completing an eight-day test flight around the moon to verify technologies 
for a planned lunar sample return mission, an unpiloted Chinese space 
capsule re-entered Earth's atmosphere at blazing speed Friday and parachuted 
to a successful landing.

Images released by China's official state-run Xinhua news agency showed 
recovery crews swarming the landing capsule after it touched down at 2242 
GMT (6:42 p.m. EDT) Friday in the China's remote northern region of Inner 
Mongolia about 300 miles from Beijing.

The landing occurred around dawn Saturday, local time, and the return 
capsule appeared intact but charred from the heat of re-entry.

The landing vehicle was expected to perform a "skip re-entry" during its 
descent, using two dips into the atmosphere to dissipate its 25,000 mph 
return velocity before deploying parachutes for the last phase of the 
landing sequence.

The mission - nicknamed Xiaofei, or "little flyer" on Chinese social media 
networks - launched Oct. 23 from the Xichang space center aboard a Long 
March 3C rocket.

Traveling 840,000 kilometers - about 520,000 miles - on the round-trip 
journey, the spacecraft flew around the far side of the moon and returned 
a dramatic view of Earth and moon perched in the blackness of space.

On the mission's return leg, the landing capsule separated from a mothership 
craft for the plunge back into Earth's atmosphere.

About the size of a washing machine, the landing craft lowered into the 
atmosphere twice, bouncing back into space and skipping like a rock across 
water before falling to Earth. Such skip re-entry maneuvers can diminish 
the speed and reduce the heat encountered by a spacecraft streaking back 
to Earth.

"Really, this is like braking a car,' said Zhou Jianliang, chief engineer 
with the Beijing Aerospace Command and Control Center, in a report by 
Xinhua. "The faster you drive, the longer the distance you need to bring 
the car to a complete stop."

"The 'bounce' was one of the biggest challenges of the mission, because 
the craft must enter the atmosphere at a very precise angle," Xinhua reported. 
"An error of 0.2 degrees would have rendered the mission a failure."

The flight around the moon paved the way for the planned Chang'e 5 probe 
to launch in 2017 and return bits of lunar rock and soil to Earth.

Unofficially called Chang'e 5 T1, the test flight validated heat shield 
technology, trajectory design, and recovery procedures for the sample 
return mission, a Chinese scientist said.

The landing capsule's host platform was expected to fire rocket thrusters 
after releasing the instrumented re-entry module to dodge Earth and head 
back out into space for continued operations.

The mission carried a piggyback suitcase-sized instrument package on the 
Long March rocket's upper stage made by LuxSpace, a company in Luxembourg 
that developed the secondary payload to honor the memory of Manfred Fuchs, 
a pioneer in Europe's commercial space sector.

Fuchs founded Bremen, Germany-based OHB - LuxSpace's parent company -
and grew it into a leading satellite and rocket contractor. He died in 
April.

The payload package carries a radiation monitor and a radio beacon, and 
officials expected it to remain in an orbit stretching up to 250,000 miles 
from Earth aboard the Long March rocket stage.

With Friday's landing, China became the third country to achieve a round-trip 
flight around the moon.

China launched two orbiters around the moon - Chang'e 1 and Chang'e 2 
- in 2007 and 2010 to survey the lunar surface.

The Chang'e 3 lunar probe landed Dec. 14, 2013, making China the third 
country to achieve a soft landing on the moon after the United States 
and the former Soviet Union.

Chang'e 3 deployed a small rover named Yutu, which drove away from the 
mission's stationary landing platform, collecting images, studying the 
composition of the moon's soil and rocks, and probing the moon's underground 
structure with a ground-penetrating radar.

Chinese officials said Yutu suffered a glitch in a control system in January, 
rendering the rover immobile and exposed to cold temperatures during lunar 
nights, which last two weeks.

Earlier this month, Xinhua reported the Yutu rover was losing functionality 
but still alive after nearly 10 months on the moon, surpassing the craft's 
original design lifetime of three months.

"Yutu has gone through freezing lunar nights under abnormal status, and 
its functions are gradually degrading," said Yu Dengyun, chief designer 
of China’s lunar probe mission, in a report by Xinhua.

"We hoped the moon rover would go farther, and we really want to find 
the true reason why it didn't," Yu told Xinhua in an interview.

China developed a backup mission for the Chang'e 3 lunar lander. The backup 
spacecraft, named Chang'e 4, will now help prove systems required for 
the more ambitious Chang'e 5 mission, Xinhua reported. Details on the 
specific objectives and planned launch date for Chang'e 4 have not been 
released by China.

The Chang'e 5 mission will follow with launch in 2017 to collect 2 kilograms 
- about 4.4 pounds - of soil from beneath the moon's surface and return 
it to Earth, Wu Weiren, chief designer of China's lunar exploration program, 
told the Xinhua news agency.

"Aside from the high-speed re-entry, major technological challenges for 
the craft center on surface sampling, taking off from the moon, and lunar 
orbit rendezvous, Wu said," Xinhua reported.

China also has plans for a Chang'e 6 sample return mission some time before 
2020.

China is studying sending astronauts on lunar missions after scouting 
the moon with robotic spacecraft, according to official media reports.

Near-term plans for China's human space program are focused on constructing 
a space station in low Earth orbit.