Shuttle in Shipshape: Part II
Once in orbit, the visual inspection of Discovery will continue with the help of a new piece of robotic technology. The Canadarm found inside Discovery's payload bay now includes the Canadian-built Orbiter Boom Sensor System. The boom extension houses a camera and laser-powered measuring device that astronauts will use to scan the orbiter's exterior. The boom attaches to the end of the existing robotic arm and doubles its length to 100 feet long. The extra length will allow the arm to reach around the spacecraft for the best possible views. With the new boom, astronauts will take a good look at features like the orbiter's leading wing edges, which are now closely watched by an advanced monitoring system.
Image to right: The orbiter's Remote Manipulator System, or Canadarm, rests inside of the payload bay. The Canadarm is used for such tasks as hoisting modules for the International Space Station and providing a work platform for spacewalks. For Return to Flight, NASA has equipped the arm with an attachable boom for scanning the vehicle's surfaces.
Each of Discovery's leading wing edges are outfitted with 22 temperature sensors to measure how heat is distributed across their spans. Both wings also have 66 accelerometers apiece to detect impacts and gauge their strength and location. The sensors are highly sensitive and take 20,000 readings per second. This new network of sensors running along the wings provides an electronic nervous system that gives engineers a valuable way to monitor their condition.
Image to left: Discovery's wings are now monitored by a network of tiny temperature and impact-detecting accelerometer sensors. Each of the sensors takes a measurement 20,000 times per second. The sensors were installed inside the orbiter's wings by technicians at NASA's Kennedy Space Center.
Inspection of the wings will continue once Discovery returns to Earth. Technicians will use a proven method called flash thermography, employed to examine the Reinforced Carbon-Carbon panels that make up the wing's leading edges. The technique starts by applying an intensely hot and bright burst of light to the panels. Technicians then survey the panels with a heat-sensitive infrared camera to see if any flaws appear under stress from the extreme heat. Flash thermography will reveal even small imperfections and offer technicians a powerful tool for keeping an orbiter's wings in shipshape.
On launch day, when the Shuttle's boosters erupt with fiery thrust and shake the Florida sands, the moment will signal the culmination of more than two years of thoughtful planning and hard work to send America's flagship spacecraft streaking back into space on a mission to the world's most unique research platform, the International Space Station. It's a mission that promises to begin with a safe and exciting reach for the sky and end with an even happier landing.
+ Return to Part I
NASA's John F. Kennedy Space Center