International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / This paper presents the findings of the Space Tracking Systems/Options Study (STS/OS) and indicates its impact on the telemetering community. The STS/OS was commissioned by Air Force Test & Evaluation (AF/TE) to develop a long range plan (vision and roadmap) for the AF Test & Evaluation (T&E) community to ensure affordable capabilities (telemetry, tracking and commanding) for the future (2003-2008). The study was conducted by the Air Force Materiel Command (AFMC), Space & Missile Systems Center (SMC), Detachment 9, at Vandenberg AFB (VAFB), with support from the primary AFMC T&E centers, the Air Force Operational Test & Evaluation Command (AFOTEC), and the Air Force Space Command (AFSPC). Both "open air" aeronautical and astronautical test needs were considered. The study solicited requirements for existing and future programs, extrapolated existing and planned test capabilities out into the future, then compared the two to identify future shortfalls in capabilities and specific actions that are necessary to insure that the future program needs can be met. Three critical types of testing were identified that cannot be satisfied with existing or planned instrumentation. These are: large area testing (LAT), over the horizon testing (OTH), and space weapons testing (SWT). A major deficiency was also uncovered in end game scoring for air and space intercepts, where inadequate capability exists to perform the required vector miss-distance measurement. This paper is important to the telemetering community because it identifies the Global Positioning System (GPS) as the primary time space position information (TSPI) system for all future open air testing. GPS provides a passive capability that permits each vehicle to determine its own precise TSPI. Means must be provided, however, for the vehicle to relay its position to the appropriate range control center. The paper shows that the problems with down linking telemetry, aircraft buss data, digital audio, digital video, and TSPI collectively represent the need for a very capable datalink. Likewise, the need to uplink commands, synthetic targets, synthetic backgrounds, and target control information also represents the need for a very capable datalink. With its extensive expertise in RF linkages, the telemetering community is ideally suited to address this need for a robust datalink for the future of T&E.