Led by teacher-turned-spaceflyer Barbara Morgan and astronaut Alvin Drew Jr., the 10 astronauts aboard ISS and Endeavour are stepping up work to transfer about four tons worth of cargo between their two spacecraft.
The day's activities come after NASA mission managers decided that a small gouge in the heat-resistant tiles of Endeavour's heat shield did not require a spacewalk repair.
"The word that we are getting is that this is more an issue for the orbiter's reuse and not our personal safety," Morgan, who served as NASA's backup Teacher in Space for Christa McAuliffe before the 1986 Challenger accident, told reporters Thursday. "Spaceflight is risky, but we all have confident that we're going to be able to do the right thing."
After a week of analysis and testing, NASA mission managers concluded that the 3½-inch by 2-inch (9-centimeter by 5-centimeter) divot on Endeavour's underbelly did not pose a risk to the safe descent and landing of its astronaut crew.
The decision allowed the STS-118 astronauts to continue their planned mission activities Friday instead of jumping into new tasks.
In addition to moving supplies between their two spacecraft, the joint crews of the ISS and shuttle Endeavour are due to speak to reporters in the U.S. and Canada via a space-to-ground video link at about 1:34 p.m. EDT (1734 GMT).
The astronauts will also begin going over plans for a Saturday spacewalk, the fourth of NASA's STS-118 mission aboard Endeavour, to continue assembly tasks outside the ISS.
Endeavour's STS-118 has already delivered a new 4,010-pound (1,818-kilogram) girder to the station's starboard and outfitted the orbital laboratory with a 7,000-pound (3,175-kilogram) platform loaded with spare parts.
"We also have about 150 bags worth of stuff, of equipment and everything that the ground ... that our station crew needs," Morgan told students at McCall-Donnelly Elementary School, her former teaching post in McCall, Idaho, Thursday. "And we've been transferring that back and forth, and that's what we've been really busy with lately."
Most of that cargo, about 5,000 pounds (2,267 kilograms) of it, sat tucked away in the SPACEHAB module inside Endeavour's payload bay for later delivery.
The pressurized cargo pod is making its last trip into space with Endeavour's STS-118 mission and will haul about 3,000 pounds (1,360 kilograms) of science experiment results, unneeded equipment and other items back to Earth aboard Endeavour.
While two of the modules will remain primed for future flights through NASA's September 2010 retirement date, upcoming ISS shipments aboard U.S. orbiters are expected to ride up in the agency's Italian-built Multi-Purpose Logistics Modules, mission managers have said.
"We're all sad that this is the last module mission," Don Moore, director of ground operations for SPACEHAB at the firm's Cape Canaveral, Florida, has said. "It's kind of hard to see that go away."
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