Shuttle Endeavour Cleared For Return To Earth

Shuttle Endeavour's is being cleared for atmospheric reentry after an extensive inspection and analysis of shuttle heat shield components and a trio of problems deemed minor by managers.

NASA's Damage Assessment Team recommended mission managers take no action in regard to a protruding ceramic tile near one of Endeavour's cockpit windows, a metal alloy seal sticking up out of the ship's left wing and a cracked tile on the rook of the cockpit.

The engineers determined that it is unlikely that the insert, the inconel seal or the cracked tile might be dislodged during atmospheric reentry and landing. But even if they became dislodged, the engineers determined that none of them could generate enough kinetic energy to do any severe damage to critical areas of the orbiter.

The small ceramic insert was found protruding from the area surrounding Endeavour's cockpit window No. 2, which is located in from of the commander's seat on the flight deck of the orbiter. Engineers were concerned that it might strike the shuttle's vertical stabilizer or its rudder speedbrake.

The cracked tile had been repaired with an RTV -- Room Temperature Vulcanizing - silicone prior to launch. But the repair failed. Engineers determine it could hit the shuttle's Orbital Maneuver System pods if it was dislodged. But it would not strike with enough force to cause significant damage.

The seal protruding from the shuttle's port side wing is not expected to pop loose during atmospheric reentry and landing. If it did, there is a possibility it might strike the elevon cove area of the wing. But it would not cause more than superficial damage if it did.

The 3.8-inch portion of the lengthy seal slipped through a flipper door than covers a cavity that holds hydraulic actuators and hinges that enable the elevons to travel 40 degrees up and 25 degrees down during ascent and atmospheric reentry and landing. A series of more than a dozen flipper doors cover the area that connects the wing with the elevons, which operate much like wing flaps on a conventional aircraft.

The seal serves to vent air from the cavity during ascent and reentry. Engineers determined it is located so far back from the leading edge of the wing -- in the "aerodynamic shadow" -- would not experience high heating during atmospheric reentry and landing.

One more late inspection of the shuttle's wing panels and nose cap will take place the day after Endeavour departs the station. Basically a repeat of the day-long inspection done on Flight Day II, the late inspection is aimed at spotting any damage from micrometeorite or orbital debris.