During April and October 1994, the Space Shuttle Endeavor flew missions expressly to study Earth's surface and atmosphere. Among the instruments aboard the shuttle was the Measurement of Air Pollution from Satellites (MAPS) Experiment, which measured carbon monoxide in the middle troposphere. While the spacecraft was in orbit, the flight crews photographed the planet with a variety of cameras and films. Concurrent aircraft and ground-based measurements of CO were made at a number of locations between northern Alaska and the edge of the Antarctic continent.
The combination of the middle tropospheric CO from MAPS and measurements made from the ground and from aircraft provide a unique picture of carbon monoxide in the lower atmosphere. Never before has such extensive knowledge of the CO distribution been obtained.