Astronaut Earth observations during the space radar laboratory missions

Astronaut science operations and observations aboard Space Shuttle Endeavour were an integral part of two 1994 Space Radar Laboratory(SRL) missions. The crews performed three major functions in support of the radar and atmospheric pollution experiments: (a) maneuvering and pointing Endeavour to cover the hundreds of planned science targets; (b) managing the flood of science data produced by the radars, generated too rapidly for immediate downlink to Earth; and (c) documenting through visible and infrared photography the environmental state of each science site, capturing “ground truth” for comparison with the other mission data sets. Earth photography was planned specifically to enhance science return from SRL´s instruments: an advanced imaging radar (SIR-C/X-SAR) and a tropospheric carbon monoxide sensor (MAPS).The astronauts went beyond the maintenance of Endeavour as a science platform to play an active role in experiment operations and science activities during Radar Laboratory operations. By far the most intense and rewarding of these activities was the crew science photography. This imagery constitutes a unique data set on the global environmental state during two seasonal extremes, April and October 1994. The crew captured over 20,000 images of Earth, complementing the unprecedented perspectives on geology, hydrology, oceanography, ecology, and the global carbon cycle gained from SRL radar imagery and pollution measurements. Examples of combined studies of SRL radar and photographic data are presented. A sampling of images from the data set is presented which demonstrates the utility and responsiveness of current Shuttle photography to global change investigators