TrKkrj ft D*ta 
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(TDRSS) 
NASCOM 
Fig. 1. EOSDIS includes facilities for mission planning, command and control 
of EOS instruments and platforms, communications between elements, 
and for processing, archiving, and distributing EOS data. 
handle the processing, archiving, and distribu 
tion of data from the NASA payloads for the du 
ration of the EOS mission. The DAACs include 
the IDPGFs and Data Archive and Distribution 
Systems (DADS). After the EOS mission, provi 
sions will be made for these archives to become 
"permanent" archives. Alternatively the data 
may be transferred to permanent archives of 
other agencies (such as NOAA/NESDIS and the 
DOI/U.S. Geological Survey) under cooperative 
management and archiving agreements. Transition 
plans will be developed to ensure that data in 
the active and permanent archives are managed in 
similar fashion and that the main effect of 
transition is in improved long-term coordination 
of archive management and funding between agen 
cies . Memoranda of Understanding between NASA 
and the USGS and NOAA, respectively, are already 
in place to facilitate this coordination. 
Exchange of commands, algorithms, and data with 
ESA, Japan, Canada, and other non-NASA entities 
involved in the EOS mission will take place 
through EOSDIS. Through its Information 
Management Sytem (IMS) EOSDIS will provide in 
formation to users on the location and content 
of EOS and non-EOS Earth science data sets and 
will make provisions for ordering and acquiring 
EOS data from instruments that must be scheduled 
in advance and for acquisition and processing of 
standard data sets for the user community. 
Several existing NASA institutional facilities 
will provide support to EOSDIS. These facili 
ties include the Space Network (SN), the NASA 
Communications Network (NASCOM), the Program 
Support Communications Network (PSCN), and the 
Customer Data and Operations System (CDOS). The 
Space Network consists of the Network Control 
Center (NCC) at the Goddard Space Flight Center 
(GSFC) and the Tracking and Data Relay Satellite 
System (TDRSS), which includes the Tracking and 
Data Relay Satellites (TDRSs), the White Sands 
Ground Terminal (WSGT), and the Second TDRS 
Ground Terminal (STGT) also located at White 
Sands, New Mexico. These ground terminals will 
support all types of TDRS service for multiple 
spacecraft, including EOS, and will have enough 
redundancy to meet all data timeliness require 
ments. For science data transmission from the 
platforms to ground EOS has been allocated one 
equivalent 24-hr 300 Mbps Ku-band channel. A 50 
Kbps S-band link will be available for downlink 
of real-time telemetry and for uploads of com 
mands from the ground to the platforms. 
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