1.5.1
The Space Research and Space Operations Services

The Space Research Service and the Space Operations Service (SOS) need to be protected and managed in order to enable the community to operate its spacecraft and to retrieve data taken by them. Without these bands, spaceborne science cannot be carried out.

The SRS covers the communications services necessary for spacecraft launch and for data communications with spacecraft. The most prominent network supporting near-Earth missions related to both Earth science and space science is the NASA Deep Space Network (DSN), an international network of antennas operated by the Jet Propulsion Laboratory for NASA. The DSN supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions.

The SRS also includes communications for space radio astronomy (space very long baseline interferometry) using antennas in Earth orbit. The spacecraft transmit the data to ground stations for processing and analysis.

1.5.2
Frequency, Time, and Position Systems

The Standard Frequency and Time Signal-Satellite Service, as well as navigational systems used by the science community, provide position data needed for measurements of motions of Earth’s crust and glaciers as well as for navigation of our spacecraft. They also sometimes support intrinsic scientific uses in addition to navigational purposes—for example, measurements of general relativity.

These systems provide timing virtually anywhere on Earth, orders of magnitude more accurate than any other system. GPS provides timing with an accuracy that can be exceeded only by having an atomic clock located in a laboratory.

The International Global Navigation Satellite System (GNSS) (IGS), formerly the International GPS System, is a voluntary federation of more than 200 worldwide agencies that pool resources and permanent navigation satellite station data to provide the highest-quality data and products in support of Earth science research, multidisciplinary applications, and education. Currently the IGS includes two GNSSs—GPS and the Russian Global Navigation Satellite System (GLONASS)—and intends to incorporate future GNSSs, such as Europe’s Galileo system. The IGS is primarily used by the EESS for spacecraft position and timing information in support of remote sensing. There are also experimental scientific uses of IGS for radio science and bistatic radar.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement