Practical astronomy. A logbook and calculator used by a crewmember of the Kuiper Airborne Observatory (KAO). The logbook details the times at, which liquid helium and nitrogen were added to the cryogenic system of the KAO's far-infrared telescope. At right is a chart used to plan observations with an infrared polarimeter fitted to the telescope. The calculator, a programmable type, may be used for work on preliminary data. NASA Kuiper Airborne Observatory: Astronomy from the stratosphere. NASA AMES Research Center at Moffett Field, Mountain View, California. Data gathered during a mission to be analyzed.