1. Very Long Baseline Observations Made with an Orbiting Radio Telescope;Levy;Science,1986
2. N.S. Kardashev The Radioastron mission and cosmology, this issue
3. V. Slysh Technical aspects of Radioastron, this issue
4. H. Hirabayashi Introduction to the VSOP mission and its scientific goals, this issue
5. R.T. Schilizzi Future developments in space-VLBI, this issue