Supplement to the 1975 report on active and planned spacecraft and experiments

A listing and brief description of spacecraft and experiments designed to update the January 1975 report on active and planned spacecraft and experiments to March 31, 1975 was presented. The information is given in two sections. In the first, spacecraft and experiments that have become known to NSSDC since the original report or that have changed significantly are described. In the second, an alphabetical listing is given for all spacecraft and experiments described in the first section and in the original report. It also updates status of operation and launch dates to March 31, 1975.