Scientists check on tracking equipment used for monitoring the return of the capsule of Shenzhou VI at the main landing area in Siziwang Banner County, Inner Mongolia Autonomous Region yesterday.

Scientists will decide when to bring China's second piloted spacecraft Shenzhou VI back to Earth, the weather at the landing site in Inner Mongolia Autonomous Region being the key factor.

The return time will be fixed in accordance with meteorological and other conditions at the main landing area in Siziwang Banner County, said Wu Guoting, senior researcher with the China Research Institute of Space Technology.

Wu said the return may occur on, before or after the fifth day of Shenzhou VI's lift-off on Wednesday morning.

The spacecraft has been well prepared for a longer journey, with supplies of food, water, oxygen, and other necessities - enough for a seven-day space flight.

The primary landing area for China's orbiting manned spacecraft Shenzhou VI has been well prepared and is ready to welcome the two taikonauts (Chinese word for astronauts) back home.

Wang Zhichao, head of the army radar team at the landing site, said if the wind blows at a speed above 10 meters per second at 100 meters above the ground, it will be unsafe for the re-entry module to land.

Li Yonghui, head of the troop's meteorological team, said: "In the coming few days, weather conditions at the primary landing area will be basically suitable for the taikonauts to return."

Eight helicopters are ready to retrieve the re-entry module. Day and nighttime search and rescue exercises have been conducted.

Colonel Yuan Shuili, with a flight record of more than 3,000 hours, will pilot the first rescue helicopter and land it at around 50 meters from the planned landing spot of the capsule.

A special highway for recovery of experimental equipment aboard the Shenzhou VI opened to traffic on Friday morning. It is expected to make the recovery process more efficient.

Siziwang Banner County would remain unknown to most Chinese, and the world, if Shenzhou VI's primary landing area was not located there. The county is located in the Ulanqab League prefecture of north China's Inner Mongolia Autonomous Region and is about 150 kilometers north of the regional capital, Hohhot. The county used to be a fiefdom of four descendants of a brother of Genghis Khan.