Astronauts from the U.S. Shuttle Discovery made a historic space walk Wednesday to trim loose padding between the craft's hull tiles and help ensure a safe journey home on August 8, dpa reported today. American Stephen Robinson and Japan's Soichi Noguchi exited at 0848 GMT and spent two hours fitting an external tool and parts platform to the International Space Station (ISS), where the Discovery docked last Thursday. After replacing a component of a scientific experiment, Robinson next turned his attention to removing two tufts between the tiles that were discovered during a spacewalk Saturday. "It's conceptually very simple but has to be done very, very carefully," 49-year-old Robinson said before the sortie lasting up to seven hours. Amid acute concern for the mission after the loss of the Shuttle Columbia in February 2003, U.S. space chiefs decided to remove the filler protruding from between the tiling on Discovery's underbelly. Even the smallest irregularity among the thousands of fillers may pose a risk when the shuttle re-enters the atmosphere next Monday. The jutting fillers could create enough friction to raise the temperature by up to 30 per cent, technicians estimate. The space walk was monitored by controllers in Houston, Texas, and at the Russian flight centre by Moscow, which jointly runs the ISS with NASA. Using the space station's robotic arm, Robinson was to swing under the shuttle's belly and try with his gloves to pull out the pieces of ceramic-coated cloth between the cracks of the thermal tiles. Only slight force was allowed to prevent dislodging any of the ceramic tiles, which are coated to withstand temperatures of more than 1,200 degrees Centigrade during re-entry into Earth's atmosphere. Should the cloth fail to move, the astronaut was to use a hacksaw and forceps to trim off the protrusions. --mor 1506 Local Time 1206 GMT
