Mission Support for the Space Shuttle

What started out as a backup image analysis procedure for the return to flight of the Space Shuttle turned out to be a key mission support capability, and REAL D Scientific technology played an important role.

As part of the return to flight process for the Space Shuttle, NASA developed techniques to inspect the Shuttle's thermal protection system once in orbit.  Although a suite of laser-based sensors were the primary inspection technology, NASA's Image Science and Analysis Group (IS&AG) at the Johnson Space Center developed a backup technique to three-dimensionally measure potential damage to the Shuttle.  IS&AG selected stereo-based photogrammetry for this application.  Photogrammetry is the science of making quantitative measurements using images taken from different perspectives of an object.  Stereo-based photogrammetry allows overlapping images to be fused into stereo pairs, which provide a three-dimensional perspective.  The three dimensional imagery is generated via photogrammetry software, but requires special glasses to view.  After extensive review, IS&AG selected the photogrammetry software from Cardinal Systems LLC, with viewing hardware from REAL D Scientific.

Shortly after the launch of the STS-114 Discovery mission in July 2005, the stereo photogrammetry system, with REAL D viewing hardware, was quickly put to use in an analysis of the unexpected foam shedding from the Shuttle's External Tank (ET).  Since the ET falls to Earth after separation from the Space Shuttle, images of the ET taken from the Shuttle shortly after separation are the only documentation of the ET damage.  Within 24 hours of receiving the imagery through downlink from orbit, IS&AG and Cardinal Systems personnel had mapped the principle damaged areas to support preliminary analysis.  Photogrammetric analysis, made possible in part by the REAL D viewing hardware, represented the most readily available technique for documenting the condition and damage to the ET following the STS-114 launch.  Refinement of the ET stereo-based photogrammetric analysis continues as engineers try to understand the failure mechanisms involved in the foam loss.

During the STS-114 mission, the REAL D system was also used to inspect observed damage to a thermal blanket below the Shuttle's left cockpit window.  Overlapping digital images of the blanket were taken by the astronauts during a spacewalk and downlinked to the Image Science and Analysis Group for review.  The images were stereoscopically oriented and experts from NASA's Shuttle thermal protection group reviewed the 3-D imagery using the REAL D glasses to determine the extent of damage.  The information obtained from the stereographic views was critical in determining that the blanket was not a hazard during reentry, avoiding another spacewalk to repair the damage.

NASA's Image Science and Analysis Group has just purchased additional REAL D Crystal Eyes glasses to support ongoing stereo photogrammetric analyses and expects significant use of this stereo analysis technique to support upcoming Space Shuttle flights.