S66-27376 (19 Feb. 1966) --- Astronaut Eugene A. Cernan, pilot of the Gemini-9 spaceflight, practices with the Astronaut Maneuvering Unit during tests in Chamber B, Environmental Test Laboratory, Building 32. The AMU consists of a chest pack and a backpack. It is scheduled for use during Gemini-9 extravehicular activity (EVA). Photo credit: NASA