Live in Orbit: Landing Systems Put To Test

Blogger update, 12:24 p.m.: Today's "hot-fire" test of the thrusters Endeavour will use to position itself for re-entry into Earth's atmosphere is complete, with all systems believed to be working properly. The crew is scheduled to conduct several media interviews starting at 12:40 p.m. Click the NASA TV image at left to launch a viewer and watch them live.

Blogger update, 11:16 a.m.: Mission controllers report a successful test of Endeavour's flight control systems, including the elevons, or wing flaps, shown in the images below taken from the shuttle's cargo bay. Next up is a test of thrusters used to control re-entry through Earth's atmosphere.

The Endeavour astronauts' last full day in orbit includes tests of critical systems needed for Sunday's planned landing at Kennedy Space Center, where NASA commentators have called the forecast "iffy."

The National Weather Service this morning shows showers likely and a possible thunderstorm that could produce gusty winds after 1 p.m. Sunday, right around the time of Endeavour's two local landing opportunities at 1:19 p.m. and 2:54 p.m.

Mission managers are scheduled to discuss the forecast and landing options at 2:30 p.m. and 4:30 p.m. today. They also are expected to update the shuttle's condition following final heat shield inspections on Friday.

If local weather does not cooperate Sunday, Endeavour can continue to fly until Tuesday or land at Edwards Air Force Base in California, where support crews will be ready. The shuttle launched Nov. 14 from KSC.

Starting around 10:30 a.m. today, the seven-person shuttle crew will begin testing the thrusters and aero surfaces needed to control the orbiter's re-entry through Earth's atmosphere.

At 3:35 p.m., Endeavour will spring-deploy from its payload bay a small, experimental Department of Defense satellite that will test two new kinds of solar cells. It's called the Picosat Solar Cell Experiment.

Other activities today include packing final pieces of equipment, dumping excess water, powering down and berthing the orbiter's robotic arm, stowing the Ku-band antenna and setting up a mid-deck recumbent seat to help astronaut Greg Chamitoff's withstand his first pull of gravity in six months.

Chamitoff replaced Sandra Magnus on the shuttle's crew, while Magnus took over Chamitoff's position as an International Space Station flight engineer.

The crew's wake-up song at about 4:45 a.m. today, "Twinkle, Twinkle, Little Star," was selected by Chamitoff's family.

Today is a light day for Magnus and her two station crewmates, astronaut Mike Fincke and cosmonaut Yury Lonchakov. They are preparing for the arrival of an unmanned Russian cargo freighter at 7:23 a.m. Sunday.

You can review today's NASA TV schedule here. Watch all the coverage live on The Flame Trench by clicking the still image above to launch a viewer, and refresh this page for updates.

The Flight Day 16 Execute Package offers a more detailed schedule of crew activities and messages sent by NASA's Mission Control Center.