(U) Space-Based Data Relay (SBDR)

(The effects of any budget/program decisions made since the information was collected during 1997-98 are NOT reflected in the National Security Space Road Map (NSSRM).)

Overview: (U)
(U)  Once data relay packages become the norm on satellites, operations can consider migrating to a Space-Based Data Relay (SBDR) environment.  For example, the control network could transition from remote tracking station (RTS) based control network to a configuration where geo-synchronous (GEO) based relay satellites service low-earth orbiting (LEO) satellites and communicate freely with mid-earth orbiting and other GEO satellites where intra- or inter-program connectivity is not feasible.  Continuous connectivity for the transfer of control and mission data will take place between a consolidated Satellite Control Center and mission satellites, avoiding gaps in connectivity and ground facility vulnerability.  A SBDR can also reduce the average time for anomaly recovery by providing longer contact coverage with an ailing spacecraft.

Description: (U)
(U)  This concept requires implementation of a common user crosslinking architecture, which emphasizes existing standards for up and down links and crosslinks, and also identifies new standards as required.  The NASA, DoD, and NOAA IPT recommended that the Aeronautics and Astronautics Coordinating Board (AACB) commit to the use of commercial and international standards, or CCSDS standards, where such standards exist and are applicable to the space environment (DoD, NASA, NOAA Satellite TT&C Integrated Product Team, Recommendations to the 29 Apr 96 Aeronautics and Astronautics Coordination Board, Final Report (Draft), 21 Mar 96, Standards Recommendation 4, page 2).  The use of such standards will promote maximum interoperability with space-based data relay systems.

(U)  NASA's Tracking and Data Relay Satellite System (TDRSS) is a present day example of one possible implementation of a SBDR concept.  The NASA, DoD, and NOAA IPT analyzed TDRSS and its possible DoD operational uses.  The group confirmed that the on-orbit TDRSS vehicles can provide only limited telemetry (TLM) services to DoD users. The working panel on TDRSS recommended the following: DoD pursue near-term TDRSS augmentation in a test and prototype mode to quantify the current level of achievable interoperability between TDRSS and DoD satellites; support the development of space-based relay operational concepts; and quantify any near-term TLM contingency/surge mission enhancing capability for DoD programs such as DMSP and GPS.  

(U) The concept varies in degree of implementation.  It would require: continuous connectivity for satellite C2 and mission data retrieval and dissemination; requires common crosslink architecture; standard Interoperable Mission Control Centers; and standard satellite bus and TT&C subsystem.  The program should leverage the TDRSS program. Technical needs include satellite crosslink technologies autonomous operations space.

(U) Driven by node vulnerability and spectrum issues NASA/DoD/NOAA IPT recommends AACB adhere to international and commercial standards.  Regarding NASA's TDRSS demonstrated relay capability, its 10 year option requires new transponders on satellites.  Programmatics include a "crawl before run" philosophy via SBLR (FY00-10 timing).  Architectures include all orbits with SGLS or EHF.  A decision to proceed will be made in FY06-07 time frame. 

User Impact: (U)
(U)  SBDR is an option to migrate existing Satellite Operations to space, once data relay packages become the norm on satellite assets.  

Programmatics: (U)
(U) Concept/Technology.
	(U) IOC: 10/2007 (1QFY2008).

(U) Organizations and Funding:
	(U) AFSPC.

Related Initiatives: (U)
(U) Space-Based Range

Related Requirements: (U)
(U) None.

Related Categories: (U)
(U) AFSCN, Satellite Operations

Road Map Placements: (U)
(U) National Security Space Road Map, SPACE FORCES SUPPORT.

Lead Office: (U)
(U) Air Force.

Date of Information: (U)
21 November 1997

(The effects of any budget/program decisions made since the information was collected during 1997-98 are NOT reflected in the National Security Space Road Map (NSSRM).)