NASA: Changes to the scope, schedule, and estimated cost of the Earth Observing System. Report to the Chair, Government Activities and Transportation Subcommittee, Committee on Government Operations, House of Representatives

Congress funded the Earth Observing System (EOS) as a new NASA program beginning in fiscal year 1991. NASA proposed to launch about 30 types of earth observing instruments beginning in 1998. These instruments were intended to improve satellite data about the earth and to provide new data to support interdisciplinary studies of the earth. EOS is seen by NASA as the first step toward a future period of space-based scientific observation of the earth. The program is directly linked to the objectives of the U.S. Global Change Research Program and international efforts to observe and study the earth. The U.S. Global Change Research Program, which is funded by 11 agencies, is an attempt to achieve these objectives and to improve predictions of climate and other forms of global change. Within that program, EOS is intended to significantly improve scientists' abilities to model, and thereby predict, broad natural relationships among the sea, land, and atmosphere; to observe how water, carbon, and other substances move on the planet or are affected by variations in the sun's radiation; and to assess the impact of human activities on the earth's climate. Ultimately, EOS is to help determine the extent to which human activities are affecting the earth's environment and to provide policymakers with the information they will need to preserve the earth