How close will the ISS be to the Russian MIR?
Mir is presently at about 380 km altitude (and very slowly coming down). The FGB/Control Module, first element of the ISS, will be launched on a Proton to 350 km altitude, and the ISS will be operating at approximately 400+ km. Orbital inclination is the same for both Mir and ISS: 51.6 degrees against the Earth’s equator. So – the distance between the two will be constantly changing but never go below a certain value (of 20-30 km for a brief moment, the difference between the two average altitudes). Any altitude difference means also that they will never be at the same phase angle for any length of time (i.e., at the same clock angle from a given reference line to the Earth’s center, meaning that a 180 degree phase difference equals largest distance because ISS and Mir would then be diametrically opposed to each other with the Earth in between). Also, of course, the Russians will supposedly deorbit Mir in mid-to-late 1999. At that time, ISS/Phase 2 should be in full swing. • How close
