Skylab 4 astronaut Gerald Carr used this small notebook during test flights of a personal maneuvering unit designed for mobility during extravehicular activity (EVA, or spacewalks). The drawing on the cover shows a free-flying astronaut in a more whimsical mobility backpack than the actual one, which was powered by small nitrogen gas thrusters. The manual contains brief operating instructions and information for quick reference. Fastened to an armband worn over the long cuff of the spacesuit glove, the spiral-bound checklist wwould be readily accessible during EVA. During the 1973-1974 Skylab missions, however, the astronauts used the checklist and tested the maneuvering unit as an experiment inside the spacious orbital workshop, not outside. NASA transferred this item and many others to the Museum after the Skylab missions were completed.