How can we increase the accuracy of determination of spacecraft׳s lifetime?

• Unpredictable atmospheric drag variations (tens of percent) are essential source of errors.
• Our goal is to increase the accuracy of the current atmospheric drag estimation.
• The traditional least square technique does not ensure an increase in the accuracy.
• Developed technique of optimum filtering of measurements is shown more efficient.
• The drag determination accuracy of several percent of the current level is achieved.

In their content, the materials of this article represent continuation of some earlier published results of studies aimed at increasing the accuracy of determination and forecasting of the orbits of low satellites [1], [2], [3], [4], [5], [6] and [7]. All these materials consider the application of the modification of the maximum likelihood technique called the technique of optimum filtering the measurements (OFM).A feature of presented materials is the determination and forecasting of parameters of the “Tchibis-M” spacecraft orbit before the reentry instant over a rather long time interval (about 10 months). This makes it possible to more fully estimate the effect of atmospheric disturbances on the calculation results and to develop recommendations on increasing the accuracy of solution of the problem in question.