This series consists of documents pertaining to NASA's unmanned space exploration (planetary reconnaissance) and satellite programs. Materials are divided into subseries by topic:

Subseries IV.A. General (1958-1971)

Subseries IV.B. JPL Program Summaries (1961-1969)

Subseries IV.C. Spacecraft Power Supplies (1960-1971)

Subseries IV.D. Earth Orbital Satellites (1959-1970)

Subseries IV.E. Planetary Reconnaissance (1957-1971)