July 6, 2005. Copyright, 2005, Graphic News. All rights reserved

Countdown to shuttleÕs return to flight

LONDON, July 6, Graphic News: When the Shuttle DiscoveryÕs boosters erupt with fire and shake the Florida sands, the moment will signal the culmination of more than two years of work to send AmericaÕs flagship spacecraft streaking back into orbit.

NASAÕs Discovery is scheduled to be the first shuttle to fly since the doomed flight of Columbia in 2003, during which a gash in the wing led to the shuttleÕs destruction over Texas during re-entry, and the deaths of all seven crew members. 

DiscoveryÕs return to flight -- planned for July 13 -- will be mission STS-114 to visit the International Space Station (ISS). Crew members will deliver food and tools, and replace one of the orbital outpostÕs four Control Moment Gyroscopes (CMGs). The gyroscopes, one of which hasnÕt worked since 2002, control the orientation of the station. The major focus of the mission, however, will be testing and evaluating new Space Shuttle flight safety, which includes new inspection and repair techniques.

Following the Columbia tragedy, an expert panel -- the Columbia Accident Investigation Board -- made 15 key recommendations. In June the panel reported that NASA was not in full compliance with three recommendations: the elimination of debris that might damage the shuttle, the ÒhardeningÓ of the spaceship to withstand such debris; and the development of a reliable in-flight repair system to fix debris damage. However, board members said NASA had addressed over 40 other safety issues and, in their view, the shuttle was safe to fly.

Most important were a brand new fuel tank guaranteed by NASA not to shed big chunks of foam insulation that could harm the shuttle, and a special tool to inspect the shuttle while in orbit for any damage to its thermal-protective skin.

Up until the Columbia accident, the bipod fitting which anchors the external fuel tank to the shuttle was protected from ice build-up by thick sheets, or ÒrampsÓ, of foam. It was one of these ramps which hit ColumbiaÕs left wing, causing the fatal damage. The new design eliminates the use of foam and melts any ice with electric heaters.

Another key change to the tank involves adding a heater to the expansion joints on an external pipe known as the LOX feedline to stop the build-up of ice. The joints allow the delivery pipe to expand and contract as it carries liquid oxygen fuel at minus-183 degrees Centigrade (minus-297 degrees Farenheit) from the external tank to the orbiter.

A further major safety improvement is the use of enhanced digital imaging equipment. NASA has nine new camera sights scattered around Kennedy Space Center in Florida. From these vantage points, NASA will photograph and record the launch of Discovery as it roars into the sky and glides through space.

Old 35-mm film cameras mounted on the shuttle have been replaced with digital cameras which will transmit image files back to Earth shortly after Discovery reaches space.

Once in orbit, the visual inspection of Discovery will continue with the help of a new piece of robotic technology. The ÒCanadarmÓ found inside DiscoveryÕs 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 orbiterÕs exterior. The boom attaches to the end of the existing robotic arm and doubles its length to 30 metres (100 feet). The extra length will allow the arm to reach around the spacecraft for the best possible views of features like the orbiterÕs leading wing edges. 

Complicating matters for NASA is the need to have two shuttles ready to fly at almost the same time, in case the first one runs into trouble and has to use the ISS as a safe haven.

>>>>>>>> OPTIONAL CUT FOLLOWS

DiscoveryÕs crew is slated to conduct at least three spacewalks while at the ISS. The first spacewalk will demonstrate repair techniques to the shuttleÕs Thermal Protection System. During the second, spacewalkers Soichi Noguchi and Stephen Robinson will install the 281kg (620lb) CMG, and on the third they will install an external stowage platform.

In DiscoveryÕs cargo bay will be an Italian-built module known as Raffaello, described by NASAÕs Scott Higginbotham, ISS mission manager, as a sort of high-tech shipping container for space station supplies.

Since the February 2003 disaster, the ISS has depended on Russian Progress cargo ships for vital supply shipments. Higginbotham says Raffaello will only be partially full at liftoff, but will be packed on its return journey.

ÒWeÕre bringing back a lot of Russian hardware that is used for automated docking,Ó he said. ÒThere are a lot of U.S. items that we want to bring back either to repair and reuse or to analyze and understand why they failed.Ó

The cargo module will be stuffed with 2,358kg (5,200lb) of broken or unused equipment, dirty clothes and other material that is currently clogging up the space station.

>>>>>>>> OPTIONAL CUT ENDS

Returning the shuttle fleet to flight is critical for the U.S. to regain its space self-sufficiency because NASAÕs contract to use RussiaÕs Soyuz spacecraft to supply the $40 billion (£20.8 billion, EUR29.7 billion) ISS expires in April 2006.
/ENDS

Sources: NASA, Associated Press