GBS consists of a space segment, fixed and transportable transmit suites, and fixed and transportable receive suites. The space segment of the current phase of GBS will consist of three UHF Follow-On (UFO) satellites; each modified with four GBS transponders and an undetermined number of leased commercial satellites. Transmit suites build broadcast data streams from various sources of information, including command, weather and intelligence agencies, and commercial television programming such as the Cable News Network. They manage the flow of selected information through the uplink broadcast antenna to the orbiting satellites for broadcast to the appropriate theaters of operation. The receive suites reverse this process and distribute the information to the appropriate end users within selected areas of operation.

The current military satellite communications architecture does not meet modern, high-data dissemination rate requirements such as video and imagery transmission. Current military satellite assets either are unable to support, or would have difficulty delivering, multi-megabit broadcasts to multiple receivers using small antennas, including mobile users, without significantly limiting or curtailing other critical two-way voice and data services to the warfighter. The Conduct of the Persian Gulf War-The Final Report to Congress, April 1992, highlights the limited ability of current military and civilian satellite communication systems to provide responsive, high-capacity communications to deployed, mobile tactical units. GBS is designed to fulfill that need.

Milestone II for the GBS Phase II system occurred in November 1997. Milestone III, currently scheduled for 1QFY00, is expected to slip due to ongoing problems with transmit suite software and design problems with the transportable receive suites. GBS Phase III, scheduled for FY06 and beyond, is currently undefined.

GBS Phase I is complete. Phase I demonstrated that the core technologies required to execute the GBS program exist and that a GBS-like capability has military utility.

The Phase II GBS TEMP was due to DOT&E in January 1998 but has been delayed over eight months as a result of Service operational tester and System Program Office difficulties in refining the combined developmental and operational test strategies. Technical issues in the program and numerous personnel changes in the Army, Navy, Marine, and Air Force Combined Test Force Team further complicated this process. These issues are indicative of the technical and management challenges that the GBS program has faced throughout its short history.

The Phase II TEMP will outline a combined T&E approach that complements the evolutionary development of the GBS system. A series of three combined developmental and operational tests in the Pacific, Atlantic, and European regions are being designed to provide feedback to the developer to enhance system performance through a series of software upgrades. Test timing and location are tied directly to the launch and operational availability of the three GBS satellite payloads. These three combined tests are designed to culminate in the near-global, multi-Service IOT&E of a fully capable GBS system by 2000.

The first UFO satellite equipped with a GBS payload was successfully launched from Cape Canaveral Air Station on March 16, 1998. Checkout of the UFO/GBS satellite payload was completed in June 1998 and the satellite was declared ready to support GBS transmit and receive suite testing in the Pacific region. However, the combined DT/OT, which was to begin at that time, was postponed three months due to software development and security-related issues impacting the fixed transmit suite in Hawaii and fixed ground receive suites in Korea. The Program Office evaluated and accepted the contractor's fixes, revised master schedule, and development approach. The first combined test is now scheduled to begin in November 1998.

Significant additional challenges to the test schedule are very likely as a result of the preceding/emerging issues, including:

The Program Office and Combined Test Force Team face continuous challenges resulting from GBS delivery schedule changes. Although the basic DT/OT test concept remains sound, changing schedules, resources, and adjustment to test objectives puts timely development of detailed test plans and orderly execution of the overall acquisition and test strategies at high risk.

The Data Dissemination and Bosnian Command/Control Augmentation efforts have demonstrated the potential capability and military utility of the GBS system. The Program Office is incorporating "lessons learned" from these efforts into the GBS system design, and the user commands are aggressively developing their concept of operations based on their early field experiences.

The GBS system contractor has overall responsibility for Y2K testing. Factory testing is done to certify that each of the system's segments are Y2K compliant. Additionally, combined DT/OT tests scheduled for 1999 will verify Y2K compliance using time-phased scenarios to demonstrate system functionality following rollover of the CPU clock from 1999 to 2000 and back. GBS will additionally be tested to recognize and operate through leap dates, 9/9/1999, and other known challenging dates. The Program Office is responsible for formal Y2K compliance certification. They plan to verify compliance using the Air Force's Year 2000 Certification Checklist.

Initial hopes of basing GBS on Commercial off-the-Shelf technology, to eliminate the challenges of a traditional high-technology acquisition program, have not been met. Although Phase I demonstrated strong system potential, the software maturity issues and transportable ground receive suite design problems demonstrate that commercial availability of a basic technology do not necessarily translate into rapid system development and integration into the military environment.