Technicians started to adjust the temperature of kerosene, fuel of China's new generation carrier rocket the Long March-7, on Friday afternoon, ahead of its maiden flight scheduled for some time between June 25 and 29 at the Wenchang satellite launch center in southern Hainan Province.
Unlike its predecessors currently in service, the Long March-7 has some changes in its propellant, using kerosene and liquid oxygen as fuel. However, the current high temperature in Wenchang will raise the temperature of kerosene, which will affect the flight of the rocket. Therefore, technicians have to use low-temperature liquid nitrogen to cool down kerosene before they fuel the rocket.
"To add the fuel precisely, we need to predict the process of heat exchange to learn how the expansion and contraction will affect kerosene, so that we can make a request for a fixed temperature to the kerosene depot. In that case, after the fueling and storing process, the temperature of propellant will rise to an optimal range before the launch," said Ma Ying, orbit designer of the Long March-7.
Technicians have finished testing the rocket's all systems so far. After cooling down the kerosene, they will start fueling the rocket on Saturday, making final preparations for the launch.
"After determining the fuel quantity, we will decide which set of parameters to be used in its flight based on the upper wind that we measure. Then we will finish the preparations for the launch," said Ma.
