The NASA Integrated Vehicle Health Management (IVHM) Technology Experiment for X-37 was intended to run IVHM software on board the X-37 spacecraft. The X-37 is an unpiloted vehicle designed to orbit the Earth for up to 21days before landing on a runway.

The objectives of the experiment were to demonstrate the benefits of in-flight IVHM to the operation of a Reusable Launch Vehicle, to advance the Technology Readiness Level of this IVHM technology within a flight environment, and to demonstrate that the IVHM software could operate on the Vehicle Management Computer.

The scope of the experiment was to perform real-time fault detection and isolation for X-37's electrical power system and electro-mechanical actuators. The experiment used Livingstone, a software system that performs diagnosis using a qualitative, model-based reasoning approach that searches system-wide interactions to detect and isolate failures.

Two of the challenges we faced were to make this research software more efficient so that it would fit within the limited computational resources that were available to us on the X-37 spacecraft, and to modify it so that it satisfied the X-37's software safety requirements. Although the experiment is currently unfunded, the development effort resulted in major improvements in Livingstone's efficiency and safety. This paper reviews some of the details of the modeling and integration efforts, and some of the lessons that were learned..

plz upload the ppt and full report on the above mentioned topic

Integrated Vehicle Health Management technology
The process of launching to and returning from the space constitutes the maximum cost for the space exploration. Integrated Vehicle Health Management (IVHM) when incorporated into the Reusable Launch Vehicles (RLVs) will reduce the cost of operation of the vehicles very much by improving reliability and lowering operational costs. safety and mission assurance consists of the Life cycle costs for the next generation RLVs. cost of processing, operating and maintaining the vehicle will dominate the cost and the time that is required for switching the vehicle for the next mision is necesary. Nasa conducted the X-37 IVHM flight experiment. The main aim of the experiment was to :
1) provide a limited demonstration of the benefits of in- flight IVHM to the operation of an RLV.
2)Inter operation of IVHM software and Vehicle Management Software (VMS) on the inbuilt vehicle management computer.

for the purpose of achieving these aims, the sensor data from selected subsystems is monitored by the flight software experiment and the software will perform perform real-time fault detection and isolation. The software will calculated the potential recovery operations during flight operations and during ground processing and checkout.

get the report here:
http://citeseerx.ist.psu.edu/viewdoc/dow...1&type=pdf