A New Window to Space

By+Yin+Pumin

Five years after construction began， Chinas fourth and most advanced space center， the Wenchang Satellite Launch Center， has been completed and is ready to start operations， the Peoples Daily newspaper reported on October 17.

Situated in Wenchang on the northeast coast of Chinas southern and tropical Hainan Island， the center is Chinas first coastal satellite launch base. Thanks to its favorable location， about 19 degrees north of the equator， the center will be mainly used to handle next-generation space vehicles and rockets， including geo-synchronous， polar-orbiting and deep- space exploration satellites and large space stations， according to Tao Zhongshan， chief engineer of the Xichang Satellite Launch Center in southwest Chinas Sichuan Province， who also revealed that the site is expected to be able to handle 10 to 12 launches a year.

“With advanced facilities， the operation of the Wenchang Satellite Launch Center will greatly improve the comprehensive strength of Chinas aerospace industry，” Tao said.

Long-planned

The coastal space centers plans have a long history. According to the Peoples Daily report， to take the advantage given to launching satellites from near the equator， Chinese space scientists first raised the possibility of building a satellite launch site in Hainan as early as the mid-1970s. The plan was later widely discussed in the late 1980s. A suborbital rocket launch site was built on the island in the 1980s， with five successful rocket launches since 1988. Preliminary research on the feasibility of a satellite launch site on the island was initiated in 1994 and its findings were submitted to the Central Government in 1996.

A number of locations on the island， including Wenchang， Qionghai and Sanya， were considered， and finally Wenchang， a small town located in the northeast corner of the island， was regarded the most suitable location for the launch site. The feasibility study and initial design of the launch site was completed in 2005. The Central Government finally gave the project go-ahead in August 2007， and construction began in 2009.

“Once put into use， the Wenchang Satellite Launch Center， Chinas first environmentally friendly launch site， will catapult the countrys aerospace industry into a new stage， with the four launch centers in China burdening different functions，” Tao said.

To date， the most widely used space facility is the Jiuquan Satellite Launch Center in the Gobi Desert， which is the countrys only manned spacecraft launch center. The other two centers are the Taiyuan Satellite Launch Center in north Chinas Shanxi Province， capable of launching satellites into both medium and low orbits； and the Sichuan-based Xichang Satellite Launch Center， mainly to launch powerful-thrust rockets and geosta-tionary satellites. China has conducted more than 100 space launches， sending over 100 satellites into space.

Advantageous

Space experts say the location of the Wenchang Satellite Launch Center offers a number of unique advantages over Chinas other three launch centers.

Long Lehao， a carrier rocket expert with the Chinese Academy of Engineering， said that rockets to be launched from Wenchang would require less fuel to enter orbit.

“The proximity of Hainan Island to the equator gives an orbital speed bonus gained from Earths rotational speed for the launch vehicle. This effectively reduces the amount of propellants required for the satellites maneuver from the transit orbit to the geo-synchronous orbit， thus increasing their service life by up to three years，” Long said.

The favorable location also allows a substantial increase in payload on the rockets to allow them to carry heavier spacecraft， Long added， explaining that the rockets can use Earths rotation to assist their ascent.

According to Long， a vehicle lifting off from the Wenchang launch center would be able to carry 7.4 percent more than one lifting off from Xichang launch center， which is 27 degrees north of the equator. With Chinas current rockets， that would mean carrying 300 kg more in cargo.

Meanwhile， the coastal location of the launch site allows rocket engines to be easily transported from their manufactories in north Chinas Tianjin Municipality to the center by ship， which allows a booster of much larger sizes to be launched from the site. “In contrast， all the other three launch centers in China can only receive engines by rail， which limits the size of the rocket to 3.35 meters in diameter，” said Pang Zhihao， a senior researcher with the China Academy of Space Technology.

According to Pang， because of the limitations imposed by railway tunnels， Chinas current launch vehicles tend to be tall and slim. “A coastal launch site can accept much larger and more powerful engines capable of carrying much larger payloads. In the future， domestic rockets could be shorter and broader， which will make them easier to control in flight and， therefore， more reliable，”Pang said.

As the new launch center faces the sea to the south and east， there is also no danger of debris from launch vehicles falling into residential areas， Pang added.

“We will most likely accomplish human treks to the moon around 2025， and the mission will depart from Wenchang，” Long told the media.

According to Pang， the Wenchang Satellite Launch Center is an ideal site for the launch of the Long March CZ-5 rocket， Chinas most powerful rocket， which is being developed. “The Long March CZ-5 rocket can be transported to the center by sea， which is impossible for the other three launch centers located in landlocked regions，” he said.

The Long March CZ-5 rocket will be mainly used for Chinas manned space station com- ponents and has the capacity to carry a 20-ton payload to near-Earth orbit， according to the China Aerospace Science and Technology Corp. It will also be used in the countrys moon exploration program.

According to the Peoples Daily report， the Long March CZ-5 carrier rocket is planned to be launched from the new center next year.

Ye Peijian， chief designer of the lunar probe for Chinas Change Project， said Change-5， the nations fifth lunar probe， will be launched from the center in 2017. It is expected to send a lunar rock sample back to Earth.