Space Network

The Space Network (SN) is dedicated to providing highly reliable, global communications coverage to NASA missions.

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Delivering the Data

The Space Network, comprised of an on-orbit constellation of Tracking and Data Relay Satellites (TDRS) and a supporting set of ground stations, securely delivers mission-critical data to customers. Building on decades of expertise and experience, the Space Network team provides flexible and reliable communications services through the TDRS satellites and associated ground-based antennas. User spacecraft connect with orbiting TDRS spacecraft located around the world and transmit their data to TDRS, which then relays the data to the Space Network ground stations. TDRS’ locations ensure that Earth-orbiting satellites are within sight of at least one spacecraft at any time.


NASA established the Space Network in the early 1980s to augment its worldwide network of ground tracking stations. The first SN ground stations were built in the 1970s at the White Sands Complex in White Sands, New Mexico, and the first TDRS launched in 1983. As more TDRS satellites launched, the constellation eventually grew to provide true global coverage for customers, which required that a new ground station be built in Guam to allow closure of the zone of exclusion (ZOE), an area over the Indian Ocean where any supporting TDRS’s could not communicate directly with the White Sands Complex because they simply couldn’t see that facility.

Once operational in the mid-1990s, the Guam Remote Station and its associated TDRS satellites expanded the Space Network to allow unprecedented 24/7 global coverage for customer space-to-ground communications. Over the decades, the TDRS team upgraded the network with new satellites to increase capacity and provide expanded capabilities. Today the SN consists of a constellation of three generations of TDRS satellites in geosynchronous orbit and four associated ground stations, relaying data between customer platforms and their ground facilities.


The Space Network makes continuous improvements and updates to its systems and resources to provide expanded capabilities for customers and to address obsolescence. Since 1983, the Tracking and Data Relay Satellite project, which supplies the network’s spacecraft, has launched three generations of spacecraft, each of which were built on the capabilities of the previous one. In 2017, they will launch the last of the third-generation spacecraft, TDRS-M. In addition to new spacecraft, the Space Network seeks to improve services available to customers through ground station upgrades, such as installing new hardware and software for higher data rates and improved IP-based communications to customer ground facilities. Currently, the team is implementing hardware at the ground stations that will nearly double data downlink rates from the International Space Station. Plus, the Space Network Ground Segment Sustainment project is working on a completely new ground architecture to further enhance customer service capabilities and reduce the effort required to operate and maintain the Space Network.

Space Segment

At any one time, the Space Network operates as many as seven Tracking and Data Relay Satellites in geosynchronous orbit around the globe. The constellation of spacecraft are positioned so that they view the whole globe at all times, providing a three-way communications relay between customer spacecraft and the ground stations in White Sands, New Mexico, Guam, and Blossom Point, Maryland for data transfer and tracking. Since 1983, NASA has launched three generations of TDRS spacecraft, continuing to increase the Space Network’s capabilities and capacity.

Ground Segment

The Space Network operates several ground stations that work in tandem with the TDRS spacecraft to guarantee continuous, global coverage to network customers. The ground terminals provide the hardware and software necessary to monitor and maintain the health of the TDRS spacecraft, measure the range of each TDRS relative to the ground, ensure that all systems are properly configured and functioning, transmit data to TDRS for delivery to customer spacecraft, and receive and process customer spacecraft data from TDRS. The ground stations are located in White Sands, New Mexico, Guam, and Blossom Point, Maryland.

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Offering reliable, 24/7 space communications to a variety of customers.