Space Network (SN) is a
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
program that combines space and ground elements to support spacecraft communications in
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
vicinity. The SN Project Office at
Goddard Space Flight Center (GSFC) manages the SN, which consists of:
* The geosynchronous
Tracking and Data Relay Satellites (TDRS),
* Supporting ground terminal systems,
* The
Bilateration Ranging and Transponder System (BRTS),
*
Merritt Island Launch Annex (MILA) relay,
*
Network Control Center Data System (NCCDS).
Satellite generations
Tracking and Data Relay Satellite (TDRS) currently consists of first-generation (F1–F7), and second-generation (F8–F10) satellites.
The space segment of the SN consists of up to six operational relay satellites in geosynchronous orbit. These
communications satellites are allocated longitudes for relaying forward and return service signals to and from customers, any entity with an Earth-orbiting satellite that has an agreement with SN to use its communications services, for data transfer and tracking. An additional TDRS, F1, provides dedicated support to the
National Science Foundation
The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su ...
(NSF) through the use of the WSC Alternate Relay Terminal (WART). Additional spare TDRSs may be in geosynchronous orbit.
All first-generation TDRSs (F1–F7, also known as TDRS A–G) carry functionally identical payloads and all second-generation TDRSs (F8–F10, also known as TDRS H–J) carry functionally identical payloads.
A third generation, TDRS K, L, and M were launched between 2013–2017.
The figures identify the pertinent communications components and associated parameters of the orbiting relay platforms.
Coverage
For spacecraft operating in a
low Earth orbit
A low Earth orbit (LEO) is an geocentric orbit, orbit around Earth with a orbital period, period of 128 minutes or less (making at least 11.25 orbits per day) and an orbital eccentricity, eccentricity less than 0.25. Most of the artificial object ...
(LEO) 73 km to 3000 km altitude, the SN is capable of providing tracking and data acquisition services over 100% of the spacecraft's orbit.
Spacecraft sent to more distant or exotic destinations rely on either
Deep Space Network or their own custom, dedicated networks.
Network Control Center Data System
The Network Control Center Data System (NCCDS) is an element of the SN ground segment.
[Space Network User's Guide (SNUG), 450-SNUG, Rev 9.] Collocated with the White Sands
Tracking and Data Relay Satellite System, the NCCDS is the operations control facility for the network. It schedules most Space Network elements and supporting elements and provides interfaces for planning, acquisition, control, and status of the Space Network. The NCCDS is the point-of-contact between customers (who have satellites in orbit) and the Space Network for most scheduling and real-time performance. A customer may obtain Space Network support by submitting specific schedule requests to or establishing generic requirements with the NCCDS. The NCCDS translates customers’ requirements into specific
TDRS communications and tracking events. Additionally, the NCCDS notifies affected customers of scheduled system outages so that Mission Operation Centers (MOCs) can properly plan mission activities. Upon MOC request, the NCCDS provides operational performance information (such as data presence monitoring indicators and data quality monitoring data) on scheduled services during actual support to determine if conditions exist that will affect data quality.
The NCCDS issues Network Advisory Messages (NAMs) to provide up-to-date information on network conditions and constraints. These messages are accessible via the NCCDS active NAM web site. The
Goddard Space Flight Center uses the NAMs as a means of letting customers know of any performance constraints associated with the
TDRS spacecraft.
See also
*
Deep Space Network
*
Near Earth Network
*
Indian Deep Space Network
*
Tracking and Data Relay Satellite
*
Eastern Range
*
SCaN Program
References
External links
NASA's Goddard Space Flight Center Space Network Official Page
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Goddard Space Flight Center
NASA radio communications and spacecraft tracking facilities