The basic scheme to the use of the above program is to find appropriate values for the space environmental parameters (solar 10 cm radio flux and geomagnetic activity index) and estimate or calculate a value for the satellite mass to area ratio. In the absence of any information on the latter quantity it is usual to employ a value of 100 kg per square metre. This is an average value for many satellites. Extreme value do not vary a great deal from this mean, with a low of 50 and a high of 200 covering 90% of relevant spacecraft. Peculiar orbiting objects may however, have values outside this range.

Having substituted the above values in the program and run it, the next step is to compare the output with the actual behaviour of the satellite in which you are interested. This will involve obtaining a list of actual satellite periods, altitudes (semi-major axes) or mean motions for a short period (maybe a few weeks if the satellite is near 500 km altitude, or a few days if the altitude is 300 km). If the program underestimates the actual decay, then you must decrease your mass to area ratio. If the program overestimates the actual decay you must increase the ratio. Eventually you should arrive at a printout which closely approximates the actual behaviour of the satellite. The future predictions of the program, together with the lifetime estimate will then be (assuming the parameters remain constant) the best estimate possible with this model.