Endeavour Reaches Space Station, Begins 11-day Mission
CAPE CANAVERAL — NASA’s Space Shuttle Endeavour docked with the international space station the afternoon of July 17, setting the stage for a series of spacewalks to install the final element ofJapan’s contribution to the orbital facility.
Endeavour and its seven-person crew launched July 15, more than a month late because of delays due to technical issues and weather. The orbiter pulled up to the station’s Harmony Node 2 at 1:47 p.m. EDT, after spending two days playing orbital catch-up with the station.
The newly arrived astronauts increased the space station’s crew size from six to 13. All five space station member organizations—NASA, the Russian Federal Space Agency, the Canadian Space Agency, the Japan Aerospace Exploration Agency and the European Space Agency—are represented aboard the facility.
Before docking, Endeavour performed a backflip maneuver so astronauts inside the station could photograph the heat shield tiles lining the orbiter’s belly. The maneuver is a now-standard part of NASA’s shuttle heat shield inspections to look for signs of damage from launch debris.
During Endeavour’s launch, an unusually large amount of insulating foam shook free from its external tank—nine to 12 bits of debris appeared to fall, though most of these occurred after the period where falling pieces are likely to cause damage. Some minor nicks to tiles were seen.
Two debris events appear to have occurred at a time when they could cause damage, and what appeared to be slight coating damage on some tiles was seen in launch video footage, mission managers said. Endeavour’s heat shield will get a full standard inspection to determine its health during the mission, they added.
Insulating foam from the shuttle’s giant external tank can impact the orbiter and damage the sensitive heat shield tiles and panels lining its belly, nose and wings. NASA’s Space Shuttle Columbia broke up upon re-entry in February 2003 due to what investigators concluded was heat shield damage caused by external tank foam debris that broke free during launch.
Endeavour mission managers were surprised by the pattern of foam loss seen on the orbiter’s external tank, as it fell in long slivers from the middle area of the tank, which has not been a problem before.
They plan to study the problem by analyzing other external tanks on the ground being prepped for future missions to see if the foam in this area is loose on other tanks. The work could potentially impact the planned launch dates of future flights, but it is too soon to tell, Endeavour mission management team chair John Shannon said during a briefing July 16.
“Strips of the foam covering the inner tank structure just kind of peeled off the primer layer of metal,” Shannon said. “We don’t understand why that actually happened. It looks like the base primer was not holding on to the foam well.”
Though the pattern is unusual, it does not appear to pose a serious threat to the shuttle this time.
“The foam loss was so late there was not a lot of aerodynamic forces going on at that point,”
Shannon said. “We’re not worried about this flight but we need to understand what was going on for the next flight.”
Meanwhile, the space station’s expanded crew has a busy schedule planned during Endeavour’s planned 11 days docked at the orbital outpost. A primary task is to install a new outdoor experiment platform on the Japanese Kibo laboratory. The segment—used to expose science projects to the space environment—will complete the huge Kibo complex.
Endeavour’s crew also plans to unload a cache of spare supplies on the station to keep the outpost running after the shuttle fleet retires, planned for 2010.