Spends First Full Day Preparing For Monday Docking With ISS

The STS-124 crew members aboard space shuttle Discovery began their first full day in space Sunday, by inspecting the orbiter’s heat shield and preparing for their impending arrival at the International Space Station.

Crew members used the shuttle’s robotic arm to perform a limited inspection of Discovery's thermal shield and the leading edges of its wings. The purpose of this inspection was to ensure no damage occurred to the protective tiles during launch.

As ANN reported, a chunk of insulating foam from the shuttle's external fuel tank struck the underside of the orbiter at T-plus 3:30 during Discovery's launch Saturday afternoon. While mission managers seem largely unconcerned about any damage caused by the foam, the fact it happened at all should give mission managers some pause.

STS-124 was the first launch to utilize an "in-line" external tank, sporting built-in modifications intended to reduce the risks of catastrophic damage to the orbiter from chunks of insulating foam. Previous tanks used since Discovery's first Return to Flight mission in July 2005, following the 2003 loss of Columbia, featured a number of modifications intended to reduce foam shedding... but STS-124 was the first to use an external tank designed from the ground-up to incorporate such changes.

The new design includes a new protuberance air load (PAL) ramp design, and titanium O2 line support brackets... both measures intended to resist ice formation.

It's impossible to completely eliminate foam shedding, simply due to the (admittedly flawed) nature of the tank's design... though NASA believed they had the shedding problem largely resolved prior to Discovery's launch. That a large chunk still separated may prove disquieting, though NASA officials believe the foam hit the orbiter late enough in the launch phase -- during which atmospheric stresses are negligble -- to not pose a significant risk for catastrophic damage.

If required, the usual detailed inspection of the heat shield will be performed later in the mission after the Orbiter Boom Sensor System (OBSS) has been returned to Discovery. The OBSS is needed to perform a complete scan, but was stowed on the station during STS-123 to make room for the Kibo laboratory’s Japanese Pressurized Module in Discovery’s payload bay.

Discovery’s crew members extended the Orbiter Docking System Ring and checked out rendezvous tools in preparation for their arrival at the station.

In addition, the STS-124 astronauts checked out spacesuits they will use during the mission’s three scheduled spacewalks at the station and participated in media interviews with radio and television stations in Minneapolis, MN and Bryan, TX.

FMI: www.nasa.gov