At about 3:25 a.m. EDT, Endeavour’s crew began a focused inspection of a damaged area on the space shuttle’s thermal protection system. The inspection is expected to take about two hours. The crew will be using sensors on the orbiter boom sensor system (OBSS) to take a closer look at an area between the right main landing gear door and the External Tank disconnect door.
Earlier this morning, the space station robotic arm grappled the OBSS from Endeavour’s payload bay then handed it off to the shuttle’s robotic arm. Pilot Greg Johnson will lower the OBSS to about a seven-foot distance above the damage site. The goal will be to take three integrated digital camera views and make two passes with the laser camera system to gather close-up imagery of the damage site. Meanwhile, the station’s robotic arm will be positioned on the other side of Endeavour with its cameras looking under, toward the orbiter, to allow the crew to monitor clearances between the orbiter and OBSS.
The data will be downlinked for analysis. Flight controllers are fairly confident the area will be cleared using the higher fidelity data acquired from this inspection.