by TSAT Program Staff
The Air Force has faced many challenges over the years in the acquisition of complex space systems. Under the direction of the Undersecretary of the Air Force, Dr. Ronald Sega, the Air Force developed a Back to Basics approach to maximize the probability for success in its space acquisition programs. This approach focuses on mission success, a key tenet of which is ensuring that technologies are matured to the appropriate levels during the acquisition lifecycle. The Transformational Satellite Communications System (TSAT)a system that is being designed to introduce technologies that will address warfighter needs 10-15 years from nowimplemented this back-to-basics approach and successfully matured key technologies to a level that will ensure success on this vital satellite system.
TSAT will be a major enabler of the Transformational Communications Architecture (TCA). The vision of the TCA is to provide a protected, secure Internet-like communication system that integrates space, air, ground, and sea networks. On a global scale, TSAT will provide high assurance, automated and dynamic capabilities. In addition to providing a significant increase in capacity over current satellite systems, specific emphasis is placed on providing new capabilities through the use of technologies such as Internet Protocol, onboard routers and large aperture antennas. These technologies provide the potential for enabling Communications On The Move (COTM) to users with small terminals and allow TSAT to collect information from protected Airborne and Spaceborne Intelligence, Surveillance and Reconnaissance assets to enhance situational awareness. TSAT delivers these capabilities in a broad, integrated information-sharing environment, thereby enabling interoperability on an unprecedented scale in military communications.
The TSAT program is composed of three segments and a systems engineering and integration function. The Space Segment will consist of five satellites in geosynchronous orbits interconnected by high data rate laser crosslinks. The Space Segment is also comprised of the TSAT Satellite Operations Element, which includes a primary TSAT satellite operations center for on-orbit satellite control and the CONUS Ground Gateway Element to receive high rate data transmitted by a TSAT satellite for linking into the Global Information Grid (GIG). The TSAT Mission Operations System (TMOS) is responsible for network and operational management for the TSAT system, effectively managing TSAT interactions with the GIG. TMOS will incorporate Advanced Extremely High Frequency (AEHF) mission planning capabilities as well. The terminal segment consists of the terminals that will be designed and procured by each of the armed services, based on the requirements allocations from the TSAT program. The Systems Engineering and Integration effort is responsible for integrating Space and TMOS with each other, and with a broad range of external programs including terminal programs, and the other network domains comprising the GIG.
At program initiation in 2003, the TSAT Program office, in coordination with the Government Accounting Office, identified seven unclassified Key Technology areas as requiring additional maturation. Among these were the antenna system that is being designed to support COTM; laser communications; Next Generation Processor Router, specifically software algorithms that will allow Dynamic Bandwidth Resource Allocation (DBRA) and Bandwidth Efficient Modulation (BEM). The DBRA algorithms will provide the military the ability to assign access to the system based on demand and link conditions, while the BEM algorithms allow more efficient use of available bandwidth when link conditions permit. Other key technology areas identified included cryptographic devicesHigh Assurance Internet Protocol Encryption and Transmission Security.
These Key Technology areas were the focus of the TSAT programs rigorous risk reduction and system definition activities over the last four years. The results of these activities were independently reviewed in 2007 as part of a Technology Readiness Assessment (TRA). The TRA results clearly indicate that the technology maturation efforts in each of the Key Technology areas have been highly successful and that each technology is now at an appropriate level of maturity for this phase of the program.
TSAT Risk Reduction Program
The TSAT risk reduction program featured extensive testing and demonstration of contractor prototypes associated with key technologies. The prototypes underwent extensive testing at contractor facilities, and were frequently demonstrated for a broad range of audiences. Government and Federally Funded Research and Development Center (FFRDC) personnel were heavily involved in monitoring and assessing these development and test activities.
These tests included not only functional tests of required capabilities, but so-called pre-qualification testing aimed at helping the contractor design sound programs for flight hardware qualification.
Prototypes for lasercomm terminals and digital processors underwent an additional level of testing through use of independent government test assets and programs. In 2006, and again in 2007, the prototypes were placed into MIT/Lincoln Labs testbeds that allowed operation and evaluation of the subsystem in signal environments closely approximating that anticipated for the operational system. These tests examined a broad range of required capabilities and proved highly successful in testing and demonstrating the maturity of TSATs key technologies. Oversight on the testing was provided by the TSAT program office and its FFRDC support including The Aerospace Corporation, Mitre Corporation, and MIT/Lincoln Laboratory, and, in certain cases, Air Force Research Laboratory staff members.
TSAT Technology Readiness Assessment
The TRA Independent Review Team consisted of 26 technical experts from AFRL, MIT/Lincoln Laboratory, Mitre Corporation, the Office of the Assistant Secretary of the Air Force for Acquisition, and The Aerospace Corporation. In order to provide an independent assessment of TSAT technologies, a criterion for the IRT membership was that members at present not be involved to any significant extent with the TSAT program. The primary function of the team was the identification of TSAT Critical Technology Elements and the assignment of Technology Readiness Levels to CTEs.
The CTEs were selected based upon the following criteria of criticality of the technology to the program in terms of performance, schedule, or cost; being new or novel; or being an existing technology used in a new or novel manner or in a new environment. Following the review of introductory materials supplied by the TSAT Program Office, a series of kick-off meetings with TSAT contractors, and attendance at Space and TMOS System Design Review Dry Runs, the TRA IRT Team identified approximately sixty-five potential technology items as CTEs. This list was further reduced to a final set of fourteen unclassified CTEs after the team investigated NGPR and laser communications test efforts; reviewed contractor technology demonstrations; held extensive focused discussions with program office personnel and contractors addressing technology criticality, and the viability of technology off-ramps; and continued review of numerous program documents.
TRLs were then assigned to each CTE based on DoD-established definitions that are used to communicate the maturity of the technology. In these definitions, TRL 1 represents the lowest level of technology readiness and TRL 9 represents the actual application of the technology in its final form. TRL 6, a requirement for entering into the preliminary design phase, requires testing of systems in a relevant environment.
The results of the TRA indicate that, of the original seven unclassified Key Technologies, all were identified by the TRA to be at TRL 6 or higher. Of the additional seven technologies identified by the TRA as CTEs, six were at TRL 6 or higher. For the one CTE that was not yet at TRL 6 (Application-Specific Integrated Circuits (an integrated circuit that is customized for a particular use), the TRA recognized that significant effort had been applied to maturing the ASIC process and in ensuring that a sound qualification program could be designed. While the TRA assessed ASICs as being at TRL 5, they concluded this was sufficient for the TSAT program to proceed into the preliminary design phase. They also noted that final steps needed to bring the technology to TRL 6 were already underway with completion anticipated in calendar year 2008.
The TRA team also considered the subsequent maturation steps required to take the CTEs to TRL 8 in preparation for flight or operational use, which is a required step for a program to move beyond the preliminary design phase. In no case were significant obstacles identified.
TSAT will use Internet-style technology to connect warfighters all over the world in a global information network with unprecedented carrying capacity, accessibility, reliability, and protection from jamming, eavesdropping, and nuclear effects. It is the lynchpin of 21st century net-centric warfare and will revolutionize military communications. As part of the basic to basics approach, TSAT invested approximately four years and significant resources into maturing critical technologies to the appropriate levels. The success of these efforts has been independently assessed and validated by the TRA and TSAT has clearly benefited from its risk reduction efforts. TSAT, therefore, is poised to enter the next phase of development, and continue towards its goal of delivering a revolutionary communications infrastructure to the warfighter.