May 26, 2011 06:58 GMT  ·  By

Astronauts aboard the space shuttle Endeavour have recently conducted a new heat shield inspection, meant to alleviate any lingering fears at NASA Mission Control, about the orbiter's safety. During the new survey, the shuttle's nose cap and wind edges were targeted.

The procedure was carried out several days after the STS-134 crew conducted another inspection of the shuttle. During that study, the astronauts focused their sensor-laden pole on ceramic tiles located on Endeavour's underbelly.

Two of these tiles were dented during the launch, and six other sites deserved extra attention as well. However, the results of those investigations returned positive, showing that the spacecraft will not be in any real danger during atmospheric descent.

The Orbital Boom Sensor System (OBSS) NASA used to check for heat shield integrity will be removed from the orbiter now that the inspection is complete. It will be attached to the truss rod keeping the International Space Station (ISS) together.

Generally, safety protocols call for two inspections to be conducted during a shuttle mission – one the day after launch and the second one the day before landing. The new inspection astronauts conducted replaced the one usually done before landing, since the OBSS will be left behind.

Endeavour is getting ready to undock from the ISS on Sunday, May 29. NASA Mission Control expects the shuttle to land safely at the Kennedy Space Center (KSC), in Florida, on June 1.

Current plans call for the OBSS to be installed on the outer hull of the ISS during the fourth and final extravehicular activity of the orbiter's stay on the orbital outpost. The maneuver will take place this Friday, May 27.

With the sensor pole installed on the station, astronauts living in space will be able to use the Canadarn-2 robotic arm to maneuver the OBSS into position for a wide array of studies. The robotic appendage was put together by the Canadian Space Agency (CSA), Space reports.

The fourth EVA of this mission will also be the last ever performed by a shuttle crew member. After Endeavour returns home, only Atlantis is scheduled to fly once more, marking the end of the 30-year-long Space Shuttle Program.

During the STS-135 mission, which will be conducted with a crew of only 4 astronauts, no spacewalks will be conducted. The only goal of this final SSP flight is to deliver more supplies, spare parts and experiments to the orbital facility.