The Global Positioning System and Access to Space

Daniel Alves Jr.

Abstract:	The introduction of the Global Positioning System has meant a revolution in navigation and geodesy, among other fields. It should have meant a revolution in test and range operations, but with the exception of the FTSS systems used for test operations of the Navy’s Trident missiles, GPS has not yet gained much of a foothold against the metric tracking radar, used for Time Space Position Information (TSPI) since the advent of the modem Test and Training Range after the Second World War. The use of GPS for TSPI is finally forging ahead, driven by cost as much as by any other factor. The major issue slowing down this probably inevitable change is safety. Safety presently drives almost all the requirements which a test and training range is instrumented to satisfy. While this may be proper when the unmanned vehicle involved is, in fact, under test or is being used as a simulation of some other event, the analogue starts to break down when we consider the incoming generation of commercial space launch vehicles. Unlike ballistic missiles being fired to test their reliability or their design, the commercial space launch vehicle is expected to be a relatively reliable “truck,” whose only job, like any other truck, is to deliver a payload when and where wanted, with as little attention or cost as possible. Today, space launches differ very little from the earliest experimental missile operations of the fifties and sixties. GPS can and will change this and allow a “normalization” of operations, quite different from today’s “experimental test” type of launch. This paper will address several of the issues and advantages in transitioning from the present practice of using tracking radars for TSPI and UHF Command Transmitters for control to an autonomous onboard instrumentation package, which would eliminate most, if not all, of the present large ground infrastructure presently required in the United States for any space launch operation. Included will be a discussion as to how the safety objection to untried hardware can be answered by presenting an approach for transitioning to an autonomous system by migrating from today’s systems through a system using on-board GPS-aided inertial to provide TSPI and utilizing GPS architecture to replace the UHF command system.
Published in:	Proceedings of the 1996 National Technical Meeting of The Institute of Navigation January 22 - 24, 1996 Loews Santa Monica Hotel Santa Monica, CA
Pages:	739 - 746
Cite this article:	Alves, Daniel, Jr., "The Global Positioning System and Access to Space," Proceedings of the 1996 National Technical Meeting of The Institute of Navigation, Santa Monica, CA, January 1996, pp. 739-746.
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