China's Shenzhou-9 manned spacecraft may have to rocket through an array of hazardous and potentially lethal weather conditions this summer as it nears its launch, experts said Monday.
The spacecraft is scheduled for launch in mid-June to perform the first manned space docking mission with the orbiting Tiangong-1 space lab module.
Li Dongxing, head of the meteorology office at the Jiuquan Satellite Launch Center in northwest China, said thunder will pose the greatest hazard for the ship, as well as heavy winds, precipitation and electric fields. Meteorological statistics from the last 30 years show that thunder occurs near the launch center at an average frequency of 2.6 times a month during the summer, with almost no thunder in autumn and winter.
"Although extreme weather does not happen frequently, it can lead to disastrous results if it does happen," Li said. With the help of advanced surveillance and data analysis technology, nearly 30 weather forecasters are doing their best to make precise forecasts for the craft's launch window, Li said.
Extreme temperatures will also pose a danger to the craft, as the ship's propellant could vaporize or solidify in excessively high or low temperatures. Experts working on the ship's propulsion system said the propellant will be stored in cool rooms before the ship is fueled, adding that the propellant's temperature is not likely to fluctuate after it is pumped into the rocket.
Various methods have been employed in the past to regulate rocket temperatures. Before the launch of the Fengyun-2 satellite in June 1997, experts applied cold compresses to the satellite's Long March-3 carrier rocket to cool it down after it experienced a surge in temperature at southwest China's Xichang Satellite Launch Center. Before the launch of the Shenzhou-4 spacecraft on Dec 30, 2002, cotton quilts were used to keep the rocket warm, as temperatures fell to negative 29 degrees Celsius that evening.