Chinese Shenzhou 7 “Companion Satellite” (BX-1)
Chinese Shenzhou 7 "Companion Satellite" (BX-1)
David Wright and Gregory Kulacki
Union of Concerned Scientists
October 21, 2008
As part of their mission, the Chinese Shenzhou 7 astronauts released a small "companion satellite," said to be roughly the size of a soccer ball, that carried a camera and had maneuvering capability. Some reports refer to the satellite as BX-1, which appears to stand for ban xing, an abbreviated form of the Chinese term for companion satellite, ban sui wei xing.
Goals of the mission appear to be to take and transmit to earth relatively high-resolution photographs, and to maneuver the BX-1 satellite into an orbit around the Shenzhou Orbital Module as preparation for a docking exercise planned for the Shenzhou 8 mission.
Chinese development of a mini-satellite that can maneuver around a larger satellite has raised some questions about its potential military uses. However, our analysis of the BX-1's guidance mechanism appears to indicate that it could not maneuver at close range around another country's satellite since it does not have the ability to determine the distance to the other satellite to high accuracy. Reportedly in this experiment, the plan was for the BX-1 not to approach closer than 4 km to the orbital module during its rendezvous.
