August 7, 1998
John Ira Petty
Johnson Space Center, Houston, TX
A flexible, effective monitoring and control program with wide applications for the X-38 project has been developed by the Automation, Robotics and Simulation Division of the Engineering Directorate at the Johnson Space Center.
The program, called Portable Diagnostic Terminal software, uses National Instrument Co.’s Labview language to enable an IBM Thinkpad to monitor systems of the prototype X-38 before and after flight and provide limited pre- and post-flight command capability.
Frank Delgado of the Engineering Directorate headed up the software project, which resulted in the development of the application in less than a year.
"The approach we used minimized the number of engineers needed to create the software," Delgado said. "We used an object-oriented approach to develop a common set of displays that could be used to create other monitoring applications."
The software is used on the ground to monitor the X-38’s health and status before flight tests. It can turn systems on and off.
During flight tests, while the X-38 is attached to the wing of a B-52, the terminal with the new software is wired to the vehicle and is used to prepare it for free flight. With it, the launch panel operator can declare the X-38 "ready for flight," the last step before the pilot’s decision to release the craft.
The fully functional software was delivered to the X-38 program in 1997. It has been used in six captive carry tests, with the X-38 remaining attached to the B-52, and one free-flight test.
The application will be used for the remaining flight tests of the current X-38 prototype. It also will be used in flight testing of a subsequent X-38 prototype, which will begin this fall.
"The application lets us look into the vehicle," said Debbie Buscher, software lead of the of the X-38 program. "It’s our one way of communicating with the vehicle and determining what’s going on before release."
She said methods used by Delgado and his team to develop the software resulted in a quick and rational development process.
The X-38 concept could become the first new spacecraft in two decades to orbit the Earth. The initial goal of the project was to develop a crew return vehicle for the International Space Station. The concept could be modified for other uses, including perhaps a joint U.S. and international human spacecraft that could be used in conjunction with any of several U.S. or international launchers.
Flight testing of the X-38, developed in a project with a strong focus on economy and efficiency, began last year.
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