Hubble Servicing Mission 3A Update - Dec. 19-20 launch!

Launch at last! NASA Astronauts will during this mission work in space over Christmas - something that only happens very rarely.

Launch at last! NASA Astronauts will during this mission work in space over Christmas - something that only happens very rarely.

Update for Monday Dec. 20, 02:00 CET

Main engines have shut down. Discovery is safely in orbit.

Update for Monday Dec. 20, 01:58 CET

Discovery has rolled to a heads-up position.

Update for Monday Dec. 20, 01:54 CET

Solid rocket boosters separation. Everything looks fine!

Update for Monday Dec. 20, 01:50 CET

Launch! Space Shuttle Discovery with seven astronauts - five American and two European astronauts - is finally on its way to service the Hubble Space Telescope.

Update for Sunday Dec. 20, 01:41 CET

T-minus 9 minutes and counting. Everything is still "go"for launch.

The following is a schedule of the events that will take place after the launch (adapted from Florida Today). All times are T-plus:

0 seconds - Solid rocket booster ignition and liftoff. 10 seconds - The shuttle will roll the astronauts to a heads-down position. 32 seconds - The shuttle's three main engines will be throttled down to 67 percent of maksimum power. This will put less stress on the shuttle as it passes through the sound barrier. 49 seconds - This is the point where the shuttle has the most stress on it from aerodynamic forces. 56 seconds - The three main engines are returned to full power. 2 minutes 3 seconds - Solid rocket boosters separate. 5 minutes 50 seconds - Discovery rolls to a heads-up position so it can communicate through NASA's Tracking and Data Relay System satellite. 8 minutes 25 seconds - The three main engines cut off. Seconds later the external tank separates and the shuttle is safely in orbit.

Update for Sunday Dec. 20, 01:01 CET

The last 40 minutes hold at T-minus 9 minutes. Everything is green for a launch. Keeps those fingers crossed!

Update for Sunday Dec. 20, 00:50 CET

T-minus 20 minutes and counting. Launch is in one hour. The next build-in hold at T-minus 9 minutes will occur at 01:01 CET and will last 40 minutes.

Update for Sunday Dec. 20, 00:40 CET

T-minus 20 minutes and holding. The clock will now hold for 10 minutes. The weather indicators are still all green.

Update for Sunday Dec. 19, 23:42 CET

Discovery's hatch has been closed. Once again ESA Science wishes God Speed to the crew!

Update for Sunday Dec. 19, 23:22 CET

The countdown clock is now at 1 hour 39 minutes. The next hold will be at T-minus 20 minutes which will occur at 00:40 CET. The clock will then be stopped for 10 minutes. The final hold at T-minus 9 minutes will occur at 01:01 CET and will last for 40 minutes.

Everything is ready for a launch at 01:50 CET.

Update for Sunday Dec. 19, 22:30

CET The crew has arrived at the pad, and now they enter the white room, from where they can enter the Shuttle. In a little less than one hour all crew members should be in their seats. All weather indicators remain green at this time.

Update for Sunday Dec. 19, 22:12 CET

The crew has now left their quarters. The countdown clocks have resumed at 22:00 CET. Everything seems to be "go" for a launch tonight.

Update for Sunday Dec. 19, 21:52 CET

The crew members are now being suited up for the launch.

Update for Sunday Dec. 19, 21:25 CET

The Final Inspection Team has left the launch pad. No problems were reported. The weather still looks promising, and everything is on schedule.

Update for Sunday Dec. 19, 21:00 CET

The Final Inspection Team are inspection the Shuttle and the pad. They are looking for ice build-up and for other abnormalities. The work will be done in approximately 30 minutes. The countdown is at T-minus 3 hours and holding.

Update for Sunday Dec. 19, 20:48 CET

The fuelling of the Shuttle was complete 19:30 and the tanks are continuously being topped-off. There are no reports of problems and the weather forecast still predicts 80% chance of meeting requirements. The only concern is a small risk for a low cloud ceiling.

Tonight's launch attempt for Servicing Mission 3A is the 10th.

Update for Sunday Dec. 19, 17:17 CET

Fuelling of the Shuttle has begun. There is a sense of optimism over the operation today.

Update for Sunday Dec. 19, 16:20 CET

NASA officials have approved the plan to launch Discovery tonight 1:50 CET on an 8-day mission to repair Hubble. The weather forecasts looks good: 80% chance for acceptable weather conditions.