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  Orbiter Integrated Vehicle Management Human Exploration
  and Development of Space Technology Demonstrations
  (IVHM HTDs)

Problem: The purpose of the Orbiter IVHM HTDs is to demonstrate competing modern, off-the-shelf sensing technologies in an operational environment to make informed design decisions for the Orbiter upgrade IVHM. The objective of the Orbiter upgrade IVHM is to reduce planned ground processing, streamline problem troubleshooting (unplanned ground processing), enhance visibility into systems operation and improve overall vehicle safety in support of Program goals to increase flight rate and reduce ground operations cost.
Solution: Satisfy existing ground test requirements as well as expected troubleshooting needs using an alternate means by incorporation of off-the-shelf, non-intrusive, light-weight modern technology sensing systems such as micro electromechanical sensors (MEMS), Hall Effect and photonic sensors. This also includes data processing techniques such as fast fourier analysis and neural networks.
Initial Operation Date: 10/29/98
Mission STS-95
Phase II upgrade
Technology Goal: The purpose of the Orbiter Vehicle Health Monitoring (VHM) HEDS Technology Demonstration (HTD) is to demonstrate competing modern, off-the shelf sensing technologies in an operational environment to make informed design decisions for the eventual Orbiter upgrade VHM. Technologies to be demonstrated to include: micro electromechanical sensing (MEMS) for hazardous gas detection and cryogenic distribution system vacuum jacketed line pressure sensing, Bragg-Grating fiber optic sensing systems for hazardous gas detection and structural strain/temperature determination, thermal flow meter leak detection, Hall Effect current sensing, accelerometers for pump vibration sensing, VME bus architecture, flash card memory and neural networks. The object of IVHM is to reduce planned ground processing, streamline problem troubleshooting (unplanned ground processing), enhance visibility into systems operation and improve overall vehicle safety. IVHM is essentially an evolution or a traditional vehicle instrumentation system which consists of sensors (pressure, temperature, voltage, strain, accelerometers, discretes, etc.); wiring; signal conditioning devices; multiplexing devices and recording devices.

IVHM takes it a step further by providing capabilities to process data versus merely recording data. This allows for on-board trend analysis to enunciate system degradation as well as control of in-flight systems checkout. IVHM also has the capability for more integrated and automated ground support equipment for more efficient systems servicing and checkout. Its is planned to fly two HTDs on the same Orbiter on successive flights with incorporation of additional sensors between flights. During cryogenic propellant load in terminal launch countdown, an IVHM data stream will be routed out of the Orbiter's T-0 umbilical for transmission, processing and viewing in the Launch Control Center (LCC). At approximately T-10 seconds the short periods will begin recording data. Data will be recorded on ascent, during three planned one hour snap shots periods and a post-landing snapshot. The processor will be dumped to a system after the Orbiter has landed and has rolled into its Orbiter Processing Facility OPF) bay.

Goals Supported: 1) Fly Safely
2) Meet the Manifest
3) Improve Supportability
4) Reduce Cost
5) Support HEDS


Curator: Kim Dismukes | Responsible NASA Official: John Ira Petty | Updated: 04/07/2002
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