Weekend News Flash: China’s Chang’e 2 Ends Lunar Mission Heads for Lagrangian Point -Signals New Space Era


Last year, in October, China launched its second moon orbiter, as part of the country’s rapidly growing reformed space program . Today, after finishing all its scheduled missions above the Moon, the probe has been launched out of orbit into interplanetary space, with a destination, a Lagrangian point, more than 930,000 miles away from Earth.

Lagrangian points are positions that remain constant relative to two other bodies in an orbital system. The second Lagrangian point (L2) of the Sun and the Earth is in line with the two but 1.5 million km (932,000 mi.) farther out.
“The second Lagrangian point is relatively ideal, because interference from solar radiation there is relatively low,” says the official, quoted in a People’s Daily report that can be taken as a government announcement.

Program managers considered three options for Chang’e 2 after its lunar mission: crashing it into the Moon, as they did with its predecessor, Chang’e 1; bringing it back to an orbit around the Earth; or sending it into the Solar System beyond the Moon’s orbit.

They have chosen the third but limited themselves to L2 as a destination because, they say, their deep-space tracking capability is not good enough to send the spacecraft farther. Even so, the additional mission will help prepare for missions to Mars, says The People’s Daily.

During its programmed six months lifespan, Chang’e 2 has completed all its design tasks a bit earlier, so scientists from the State Administration of Science, Technology, and Industry for National Defense (SASTIND) gave it additional missions, including snapping images of the lunar poles and flying into low-orbit to get a better glimpse of the Bay of Rainbows, a potential future landing site for Chinese moon missions.

The Chang’e surplus fuel for staying on the “safe side” didn’t have to be used, which the SASTIND used to catapult the probe deeper into space, for a ride which is set to last 85 days. It won’t be sent with a clear examination purpose, however. Instead, it will be more of a capability testing run, one to see how the Chinese instruments on the probe behave further into space like communication, data downlink, and control challenges which often arise.

Change'e 2's Lagrangian point destination is a location in space where gravitational forces and the orbital motion of a body balance each other. They were discovered in 1772 by the French mathematician Louis Lagrange, who was working on a solution to the “three-body problem”. The problem arose after scientists began wondering how a third, small body would orbit around two large bodies that are also in orbit.

“If the Chang’e-2 can get there, that will lay the groundwork for China’s future exploration of deep space,” Pang Zhihao, a researcher and deputy editor-in-chief of the magazine Space International, said.

China has set ambitious goals for the future concerning space exploration, intending on building its own ortibint space station by 2020, sending a rover to the moon surface – the Chang’e 3 mission – which will collect sample and return on its own back to earth in 2017, and a manned mission to the moon by 2025.


The Daily Galaxy via China Daily and aviationweek.com


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