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.