Contains material created and collected by engineers, technicians, and graduate students responsible for building and testing instrumentation. Much of this collection contains highly technical material required in the construction and testing phases of placing scientific payloads into space. The collection is somewhat limited because in some instances a general mission file was established by the project manager who subsumed all materials including engineering papers. Consequently such material would be retained in the project manager's mission papers. Also, in many cases, the engineers retained their files after leaving the University of Iowa. Missions documented include Injun III, Orbiting Geophysical Observatory (OGO) I, Explorers 33 and 35, Injun V, Pioneers 10 and 11, and the Hawkeye satellite.