satellites using the same frequency band of the radio spectrum." The size of the space object will, however, affect the possibility of collision. One estimate has been based on a satellite possessing a radius of 25 m. Two space objects having this dimension will have to pass each other by more than double that distance in order to avoid a collision or other possible interference. With 100 satellites of this size in geostationary orbit it is estimated that the collision cross- section would be 0.8 km and with a "total of 200 passages through the equatorial plane per day, there will be less than one collision per 500 years." Thus, for both active and passive satellites of this size the danger of collision is negligible. However, "a totally different picture emerges if large space structures are considered such as those envisaged for collection and transmission of solar energy. Assuming that such a space structure would have an area of 100 km , it would suffer one collision on the average of every five years from the hypothetical 100 small inactive satellites, which is signficant because its planned life-time would be about 30 years." Since such collisions would not necessarily result in the destruction of, or even change the motion of the large SPS, it might need only repairs and station-keeping. However, the impact could place the inactive satellites on a new orbit in which it would continue to cut through the geostationary orbit causing more than the first collision. 6UIbid., pp. 268-269. Physical Nature and Technical Attributes of the Geostationary Orbit, U.N. Doc. A/AC.105/203, p. 7, August 29, 1977. Ibid. Ibid.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==