Live in orbit: Discovery departure on tap at ISS

Discovery's astronauts are powering up spaceship systems in advance of a planned departure early today from the International Space Station -- a high-flying farewell that will include a looping look at the growing outpost.

With pilot George Zamka at the controls, the shuttle will separate from its docking port at the forward end of the U.S. Destiny laboratory at 5:32 a.m. EDT and back off to a point 400 feet away.

Then, pulsing shuttle thrusters in short bursts, Zamka will fly a giant loop around the station while camera-wielding crewmates snap photos of the outpost and in particular, the newly arrived U.S. Harmony module.

Special attention also will be paid to a repaired solar wing to see how it fared under the loads imparted during the shuttle's departure from the station.

The hourlong flyaround should afford some spectacular views of the station with Earth and black space serving as backdrops. You can watch the action unfold here in The Flame Trench. Simply click the link below the image above to launch our NASA TV viewer and round-the-clock coverage of NASA's 120th shuttle mission, the 23rd devoted to station assembly and maintenance.

A late inspection of shuttle heat-shield components will follow undocking.