http://www.eitb24.com/portal/eitb24/noticia/en/sci/tech/factbox-changes-to-s huttle-discovery-since-last-flight?itemId=D40251&cl=/eitb24/nuevas_tecnologi as&idioma=en
06/28/2006 In the year since shuttle Discovery last flew, NASA has addressed problems exposed by the 2003 Columbia disaster and other issues. Here are some key changes to the spaceship since July 2005: *Two long wedge-shaped pieces of foam insulation, which served as an aerodynamic windshield for pressurisation lines and cables, were removed from the external fuel tank. A one-pound (0.4 kg) chunk of foam from the "Protuberance Air Load" (PAL) ramps fell off during Discovery's last mission. Extensive wind-tunnel tests and analysis show the underlying equipment can withstand the forces of liftoff without the shields. In all, 37 pounds (16 kg) of foam were removed. *Sensors have been added in the cable tray to monitor stress during launch. Engineers also embedded 88 sensors behind the carbon panels of the leading edges of the shuttle's wings to monitor temperature and acceleration. *Foam shields covering metal clips on the fuel tank that are now exposed because of the removal of the PAL ramp have been extended. Like all the insulation on the tank, the 18-inch (45-cm) and 24-inch (61-cm) long foam ramps are intended to prevent ice from forming. *Electric heaters installed before Discovery flew in 2005 have been rewired. Tests show foam around the wires could pop off due to trapped air. *In addition to 55 land-based cameras and video recorders, and two imagers aboard a surveillance aircraft, Discovery's launch will be tracked by two radar systems so any debris loss from the tank or bird strikes will be known. The radar includes a new system mounted on two ships at sea. *A sound system has been installed to scare away birds. During its flight last year, Discovery hit a vulture. *More than 5,000 cloth fillers installed between heat-resistant tiles on the shuttle's belly were replaced after two of the cloth strips slipped out during Discovery's last flight and triggered an unplanned spacewalk. Engineers were concerned the strips could break the smooth flow of air around the shuttle during re-entry and cause the tiles to overheat. Seven new, stronger windows were installed in the crew cabin. The ship also has new tires and improved landing gear. Gregory S. Williams [EMAIL PROTECTED] Reply with a "Thank you" if you liked this post. _____________________________ MEDIANEWS mailing list [email protected] To unsubscribe send an email to: [EMAIL PROTECTED]
