All (Digital) Eyes Are on Discovery

Imaging and sensor technologies will play a key role in making NASA shuttle flights safer.

The Space Shuttle Discovery's 13-day mission to the International Space Station, where it was scheduled to test new safety features implemented after the Columbia disaster in 2003, was scrubbed on Wednesday due to a faulty sensor. While NASA announced no definitive timeline for a new launch, it's clear that the U.S. shuttle program will soon take flight again.

And, when it does, the three remaining shuttles will be equipped with state-of-the-art technologies designed to make space flight as safe as possible.

Since the shocking loss of seven astronauts two years ago, the Columbia Accident Investigation Board (CAIB) has recommended 15 necessary improvements, including new digital imaging and sensor technologies. And NASA has made 30 different improvements itself.

Together, these comprise NASA's "Return to Flight" plan, which outlines the latest technologies used in the revived Shuttle program. Among the overhaul's most cutting-edge technologies are new imaging and sensor systems, to improve the ability of detecting debris falls and impacts.

"Technologically speaking, the biggest improvements are the impact sensors in the wings and a new shuttle boom equipped with the new laser imagers," says Bruce Sauser, Manager of the Government Furnished Equipment and Flight Crew Equipment Management Office/MV5 for the Space Shuttle at NASA's Johnson Space Center. Sauser's office was instrumental in developing and procuring much of Discovery's new equipment.

Here's a brief summary of the key technologies used to upgrade the three active space shuttles:

Orbiter Boom Laser Imager: Perhaps the most crucial of all the Shuttle's enhancements is a new laser imaging system mounted on a boom attached to a 50-foot-long arm extension to the existing 50-foot manipulator. The combined 100-foot system will extend camera views to all parts of the Shuttle. The boom has an electrical grapple system on one end and a new laser imaging system on the other that consists of a Laser Dynamic Range Imager (LDRI), a Laser Camera System (LCS), and an Intensified Television Camera. Made by Sandia Labs, the LDRI uses an infrared laser illuminator and camera receiver to provide 2D and 3D video imagery. The LCS can make 3D video images or CAD models of impacts.

"The 3D views are important for depth measurements," says Sauser. "If a gouge or a crack exceeds a certain depth, it becomes critical. The quality of the 3D views in these systems has improved a lot over the last few years."

On the second day of the flight, the astronauts will use the boom's automated and manual arm systems to investigate the nose and wing leading-edge areas. The operators will need to maneuver these imagers within seven feet of the orbiter to get the necessary resolution. They must be careful not to hit anything and the lasers are sensitive to sudden movement -- which means the task will take over six hours.

On future missions, says Sauser, NASA plans to add higher-resolution digital cameras to the orbiter boom, which should speed up the monitoring of impacts and also avoid collisions.