Probability of collision in the geostationary orbit

The advent of geostationary satellite communication 37 years ago, and the resulting continued launch activity, has created a population of active and inactive geosynchronous satellites which will interact, with genuine possibility of collision, for the foreseeable future. As a result of the failure of Telstar 401 three years ago, MIT Lincoln Laboratory, in cooperation with commercial partners, began an investigation into this situation. Under the agreement, Lincoln worked to ensure a collision did not occur between Telstar 401 and partner satellites and to understand the scope and nature of the problem. The results of this cooperative activity and recent results to carefully characterize the actual probability of collision in the geostationary orbit are described.