Orbiter Docks At ISS, First Spacewalk Friday

Space Shuttle Discovery and the STS-120 crew arrived at the International Space Station at 0840 EDT Thursday, delivering a new module and crew member to the orbital outpost. After the hatches between the station and shuttle opened at 1039, the two crews exchanged greetings and went to work preparing for almost nine days of joint operations.

STS-120 and Expedition 16 crew members transferred to the station spacesuits and tools that will be used during STS-120’s spacewalks. The first of five excursions planned for the mission will begin at 0628 Friday.

As the crews exchanged greetings in low-Earth orbit, on the ground engineers examined images taken during Discovery's ascent into orbit... and determined a chunk of ice struck the orbiter's underside, near the liquid hydrogen umbilical door.

Florida Today reports the four-inch-long curved sheet of ice built up on the shuttle's problematic external fuel tank, along a liquid hydrogen feed line. As ANN reported, NASA watched the ice develop in the hours prior to the Tuesday launch, and determined it did not pose a risk to the shuttle.

NASA still believes the ice caused no significant damage... but the final verdict awaits detailed analysis of the images taken of the orbiter from the ISS, during Discovery's "cartwheel" manuever prior to docking at the station.

Based on earlier images, the agency did determine no focused inspection of the shuttle's heat shield will be necessary. The focused inspection is routinely scheduled on the fifth day of the mission for any additional necessary inspection of the thermal protection system.

"At this point nothing is worth a targeted inspection but there are still a lot of data to analyze," shuttle flight director Rick Labrode told Agence-France Presse.

For now, the focus is on Mission Specialists Scott Parazynski and Doug Wheelock... who will perform the first spacewalk. To prepare for the spacewalk, the duo is conducting an overnight "campout" in the station’s airlock where the pressure has been lowered to the pressure normally found on Earth 10,000 feet above sea level. The airlock stay at a lower pressure protects against decompression sickness as Parazynski and Wheelock go to the even lower pressure of spacesuits Friday.

Other post-docking activities on Thursday included a crew-member exchange. STS-120 Mission Specialist Dan Tani replaced Expedition 16 Flight Engineer Clay Anderson, who will return to Earth with STS-120. The crew transfer became official when Tani’s custom-made seatliner was installed into the Russian Soyuz spacecraft docked to the station.

FMI: www.nasa.gov/mission_pages/shuttle/main/index.html