Viewing page 205 of 218

This transcription has been completed. Contact us with corrections.

Earth Observing System/Polar Platforms (EOS):

Four large polar orbiting platforms, two of which are provided by the international Space Station Freedom program--one by the U.S. and the other by ESA. The U.S and the other by ESA. The U.S. platform would be launched in late 1996 and the ESA platform about two years later. A second U.S. platform and a Japanese platform make up the remaining part of the total Earth Observing System (EOS). These platforms are planned for a 15 year observing program for each of the four satellites in order to obtain long-term, consistent sets of global earth data on a wide-ranging number of measures of the state of the global environment. These platforms are the key elements of Mission to Planet Earth and the first elements to be deployed.

NASA has been developing the EOS concept since 1983, and has recently completed selections of science instruments, instrument team leaders and team members, and interdisciplinary scientists from an Announcement of Opportunity (AO) released in January, 1988. Several Phase B development contracts have been issued for design of various facility instruments. Goddard Space Flight Center has management responsibility for the  first U.S. platform and the Jet Propulsion Laboratory has management responsibility for the second U.S. platform.

Space Station Attached Payloads:

These are instruments to be attached to the U.S. Space Station Freedom for special studies from low inclination orbit. These studies include the role of tropical oceans in climate, and the study of the diurnal variability of some important global processes such as precipitation. These payloads will also be deployed early in Mission to Planet Earth and will be chosen later this year as part of the EOS AO process.

Earth Probes:

These are a series of small free-flying satellites for special earth studies not possible to carry out on the polar orbiting platforms. They require special orbits or spacecraft, and can be done with relatively inexpensive spacecraft and small launchers. Examples include a Tropical Rainfall Mapping Mission (TRMM) if the instruments are not flown as attached payloads, a Geopotential Research Mission (GRM) for determination of the earth's geoid and support of the Topex/Poseidon and EOS altimeter measurements, and a Magnetic Field Explorer (MFE) for study of the earth's interior structure and motions. Also in this category is continuation of the TOMS global ozone measurements in anticipation of the failure of the Nimbus-7 instrument.

Geostationary Platforms:

These are five platforms in geostationary orbit for complete, simultaneous coverage of the earth's globe at any one time. The