Chang' e 1

Firsts

Chang'e 1 was China's first deep space mission.

Key Dates

Launch: Oct. 24, 2007 / 10:05:04 UT

Eng of Mission: March 1, 2009 / 08:13:10 UT (Lunat Impact)

Results

Chang’e 1 was the first deep space mission launched by China, part of the first phase of the Chinese Lunar Exploration Program.

The program was divided into three phases: circling the Moon, landing on the Moon and returning from the Moon. The program goals were to be accomplished between 2007 and 2020.

The goal of this first mission, besides proving basic technologies and testing out several engineering systems, was to create a 3D map of the lunar surface, to analyze the distribution of certain chemicals on the lunar surface, to survey the thickness of the lunar soil, to estimate helium 3 resources, and to explore the space environment (solar wind, etc.) in near-lunar space.

The spacecraft itself was based on the design of the reliable DFH-3 satellite bus. After launch, the spacecraft entered a 127 x 31,600-mile (205 × 50,900-kilometer) orbit for a day before firing its 110 pounds-force (50 kilograms force) thrust main engine at 09:55 UT Oct. 25 to raise perigee to about 370 miles (593 kilometers).

Subsequent burns (this time near perigee) were performed Oct. 26 (at 09:33 UT), Oct. 29 (at 09:49 UT), and Oct. 31 (at 09:15 UT) increasing apogee to about 44,500 miles (71,600 kilometers), 74,400 miles (119,800 kilometers), and finally 249,000 miles (400,000 kilometers), respectively.

On its way to the Moon, Chang’e 1 (or CE-1, as it was often called in the Chinese English-language press) made one course correction before entering lunar orbit with a 22-minute burn that began at 02:15 UT Nov. 5, 2007, thus becoming the first Chinese spacecraft to orbit the Moon. Initial orbital parameters were about 130 x 535 miles (210 × 860 kilometers).

Two maneuvers on Nov. 6 and Nov. 7 lowered perigee to about 1,065 miles (1,716 kilometers) and 125 miles (200 kilometers), respectively. Its final working orbit – a 125-mile (200-kilometer) polar orbit with a period of 127 minutes -- was reached on the same day.

On Nov. 20, CE-1 returned the first raw image of the lunar surface, and by Nov. 28, all scientific instruments were fully operational.

A composite of 19 strips of raw images was issued by the Chinese media Nov. 26 at a ceremony attended by Chinese Premier Wen Jiabao. There was some controversy regarding this image which some believed was a fake or a copy of an image returned by Clementine but this proved not to be so: the high-quality image was indeed quite real.

Through December 2007, CE-1 continued to photograph the Moon (including in stereo) and began imaging the polar regions in January 2008.

The spacecraft successfully fulfilled its one-year mission after which it continued extended operations.

On Nov. 12, 2008, Chinese space authorities issued a full-Moon image map produced using CE-1 images taken over 589 orbits covering 100 percent of the lunar surface with a 400-foot (120-meter) resolution.

In December 2008, over a period of two weeks, the spacecraft’s perigee was progressively lowered to about 9 miles (15 kilometers) to test operations for future orbiter and lander spacecraft.

Finally, on March 1, 2009, CE-1 was commanded to impact the lunar surface, making contact at 08:13:10 UT at 52.27 degrees east longitude and 1.66 degrees south latitude, thus becoming the first Chinese object to make contact with the Moon. Its most significant achievement was to produce the most accurate and highest resolution 3D map of the lunar surface.

- Credit: NASA