In space research:
The computer is mostly used to do experiments and operate the machines.
It is used to determine datas and etc.
it is also used for:
filtering data for intelligent signals (SETI)
simulations of materials strength, and rockets in different conditions... like hot/cold/pressure/vacuum/acceleration.
simulations of different trajectory time vs cost vs fuel
calculations for fuel thrust/impulse vs weight of craft
simulation of landing/travelling through atmosphere
computer graphic 3D simulations of flight plans, of gathered data etc...