NEXT GENERATION SATELLITE.....

The TDRS Project is building three space communications satellites that are part of a follow-on spacecraft fleet that will replenish NASA's Space Network. The TDRS Project Office at Goddard Space Flight Center manages the TDRS development effort. TDRS is the responsibility of the Space Communications and Navigation (SCaN) office within the Human Exploration and Operations (HEO) Mission Directorate at NASA Headquarters in Washington D.C. Operations of the network are the responsibility of the Space Network Project at Goddard.

In December 2007, NASA signed a contract for Boeing Space Systems to build two third generation TDRS spacecraft for launch in 2013 and 2014. An option for a third TDRS spacecraft was executed in 2011. Within the contract there were required modifications that would enable the White Sands Complex ground system to support the new spacecraft.

The January 2013 launch of TDRS-K will begin the replenishment of the fleet through the development and deployment of the next generation spacecraft. These satellites will ensure the Space Network's continuation of around-the-clock, high throughput communications services to NASA's missions; serving the scientific community and human spaceflight program for years to come.The Tracking and Data Relay Satellite constellation is a space-based communication system used to provide Tracking, Telemetry, Command, and high bandwidth data return services to its many customers. A major component of the system is the spacecraft itself, the Tracking and Data Relay Satellites (TDRS). Aboard each spacecraft are multiple antennae that simultaneously relay signals between the ground and multiple satellites. As a result, TDRS provides a wide variety of services to meet customers' needs and demands.

The primary payload of each TDRS is the microwave communications equipment, two gimbaled antennae and a phased array antenna. The gimbaled antennae provide forward (to the customer satellite), return (from the customer satellite), and tracking services to one customer at a time.  Each TDRS communicates with customers at S-band and Ku-band microwave frequencies at various data rates.   Through Ka-Band, the 2nd and 3rd generation satellites are able to provide improved overall service potental with substantially higher bandwidth communications services.  The phased array antenna provides low-rate S-band forward, return, and tracking services to multiple customers simultaneously.  The TDRS Payload is designed to communicate through both gimbaled antennae and the phased array antenna simultaneously to customer electronic communication hardware operating at different carrier frequencies and various data-rates.