Live in orbit: Critical engine-firing coming up

The Atlantis astronauts are preparing for a critical engine firing that will slow the shuttle enough to drop it out of orbit, the first step in a supersonic slide back through the atmosphere.

Touchdown remains scheduled for 9:07 a.m. on Runway 15 at Kennedy Space Center. The runway is the north-to-south landing strip.

Flying upside-down with its tail pointed in the direction of travel, Frick and pilot Alan Poindexter will fire the shuttle's twin maneuvering engines just before 8 a.m. The two-minute, 43-second firing will put the shuttle on course for an hourlong freefall that will take Atlantis over the south Pacific Ocean, central America and the Gulf of Mexico before the ship makes landfall over southwest Florida near Fort Myers.

A "go/no-go" decision from lead flight director Bryan Lunney is expected to come between 7:30 a.m. and 8 a.m. The deobit burn is scheduled for six seconds before 8 a.m.

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 complete coverage of the STS-122 mission.