High altitude research into free molecular flow properties has become more prominent in the aerospace field in recent years due to the rise of private aerospace firms. This led to an increase in satellite launches and greater interest in the behaviour of rarefied gasses and their effect on satellites, spacecraft and space stations. The advancement in research in this field can influence the design of these space vehicles. Direct Simulation Monte Carlo (DSMC) is a reliable simulation tool for high altitude flow which has proven its worth over the past 40-50 years. This report lays the foundation for research into the effect of varying geometric shapes of satellites in Low Earth Orbit (LEO) and whether factors such as atmospheric density and temperature have an effect on the coefficient of drag. It shows that the coefficient of drag of the satellite can increase dramatically with a rise in atmospheric temperature with most structures. A variety of DSMC simulations were also carried out on a satellite with a drag plate, which was shown to produce a significant decrease in the orbital life of satellites in LEO. These simulations were carried out on generic shaped satellites as a base, then the GRACE satellite was tested. It was shown through numerical simulation that the addition of a drag plate to a satellite in LEO can alter the orbital life and rate of decay of that satellite; these rates varied depending on different orbital conditions. Future work for this project was also discussed with the emphasis on further research into the drag plate design and mechanics; this project has demonstrated the proof of concept for the drag plate well.