1. Fact Sheets: US Joint Space Operations Center, www.vandenberg.af.mil/library/factsheets/factsheet.asp?id
2. US Air Force Space Command—Change in Commercial and Foreign Entity Data Exchange Sparks Review, May 2009, www.stratcom.mil/news/article/62/Change_sparks_review
3. In the second half of 2009, Intelsat, Inmarsat, and Eutelsat formally created the Space Data Association to share information on a routine basis about commercial satellite orbits in order to minimize the possibility of orbital collisions. The organization is open to all satellite operators.