Analysis of RSO's close approaches with the ISS during two years flight

On Nov 20, 1998 the first module of the ISS - Zarya, was successfully launched from Baykonur cosmodrome. On Dec 6 1998 another module - Unity, was docked to Zarya and since that almost two years, till Jul 2000, the ISS had been orbiting the Earth in such configuration, sometimes changing it with rare Shuttle visits. It is interesting to analyze the orbital "vicinity" of the ISS during this period of relatively stable flight with minimal amount of dynamical operations. A posteriori analysis of whole orbital archive revealed some close approaches with the ISS. Technique of close approaches calculations and archive maintenance will be discussed in this presentation.