NASA's John F. Kennedy Space Center
Lockheed Martin engineers and technicians completed a series of pyrotechnic bolt tests on the Orion ground test vehicle (GTA) in the Launch Equipment Test Facility (LETF) at Kennedy Space Center in Florida May 13-17.
Earlier in the month, the GTA was transported from the Operations and Checkout (O&C) Building to the LETF. During the week, technicians individually tested five frangible, or breakable, nut detonations between the GTA and a launch abort system (LAS) retention and release mechanism. Each test took about four hours to set up and about 30 minutes to test.
The purpose of the LAS is to ignite its solid-fueled engines and lift Orion and its crew away from disaster in the unlikely event that the booster fails during the first part of launch.
"The purpose of the test was to reduce the shock levels on Orion when the launch abort system is jettisoned," said John Blair, the Lockheed Martin Orion Manufacturing Engineering manager. "Several different materials and detonation device designs were tested on the GTA, providing data that will be evaluated to choose the best design for Exploration Flight Test-1."
Orion is the exploration spacecraft designed to carry crews to space beyond low-Earth orbit. It will provide emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. Orion's first unpiloted test flight, EFT-1, is scheduled to launch in 2014 atop a Delta IV rocket.
The tests involved a LAS and measured how the explosive separation mechanism affected the GTA and its tiles as it separated the spacecraft from the LAS. The data collected from the tests will be used to assess how the shock levels, generated by the separation, affect the capsule's tiles and surrounding components.
"Shock discovery tests like this one anchor the analytical models and record the shock levels the spacecraft will experience during separation events," said Ryne Waggoner, the Lockheed Martin Orion Mechanisms test engineer. "Correctly predicting the EFT-1 shock environment is critical to protecting sensitive electronic components."
The first series of pyrotechnic tests was performed in the LETF in October 2012. Waggoner said the tests were successful, and the thermal protection system tiles showed no damage due to the shock, and all of the accelerometers collected consistent, accurate data.
The GTA is being used for pathfinding operations, including simulated manufacturing and assembly procedures in the O&C.