STS-134 Countdown Underway
The final launch countdown for Space Shuttle Endeavour is underway at the Kennedy Space Center in Florida. The teams are working towards a launch on Friday, April 29 at 3:47 p.m. EDT.
The crew of mission STS-134 arrived at the KSC at 12:50 p.m. today to begin their final preparations for Liftoff. Call to Stations occurred on time at 1:30 p.m. local time.
The launch team is not working any issues that could prevent a launch on Friday. All activities are on schedule. Endeavour’s Payload Bay doors were closed earlier today and will remain closed until the vehicle is on orbit.
What could delay the launch is the unpredictable Florida weather. The spaceflight meteorology group has issued a 20% chance of weather prohibiting launch on time. The primary concern are high crosswinds at the Shuttle Landing Facility. Good weather at the runway is necessary in case the Space Shuttle has to return to Florida shortly after launch. The team is also watching a front that will move over the area on Thursday or early Friday which will bring thunderstorms and heavy rain. This front could delay launch preparations that are planned for that time frame such as the retraction of the Rotating Service Structure. However the team can delay these activities for several hours before they would need to postpone the launch.
Another important factor for Endeavour's launch is the on-time liftoff of the Russian Progress M10-M on Wednesday, April 27 at 9:05 a.m. EDT from Kazakhstan. If the Progress launch slips for a day, Endeavour has to stay on the pad for one additional day as well. Also, the Progress has to dock on schedule in order to clear the way for Space Shuttle Endeavour. Docking should occur 10:29 a.m. EDT on Friday.
Endeavour’s launch window extends from April 29 to May 4. The launch team plans to have 4 launch opportunities during these six days, however they will decide whether they go for a 24-hour or 48-hour scrub turnaround based on how far in the countdown the scrub occurs. NASA Test Director Jeremy Graeber noted that the team would aim for a 24-hour turnaround if the countdown is aborted prior to the L-4-hour mark. After that they would go for 48 hours, but they will decide when they get that far. Endeavour has another launch opportunity on May 8 if the Atlas V currently targeted to launch on May 6 lifts off on time. The next window opens on May 10 and will stay open until late May. But the teams are confident that they will get Endeavour off the pad during their first window of opportunity.
The crew of mission STS-134 arrived at the KSC at 12:50 p.m. today to begin their final preparations for Liftoff. Call to Stations occurred on time at 1:30 p.m. local time.
The launch team is not working any issues that could prevent a launch on Friday. All activities are on schedule. Endeavour’s Payload Bay doors were closed earlier today and will remain closed until the vehicle is on orbit.
What could delay the launch is the unpredictable Florida weather. The spaceflight meteorology group has issued a 20% chance of weather prohibiting launch on time. The primary concern are high crosswinds at the Shuttle Landing Facility. Good weather at the runway is necessary in case the Space Shuttle has to return to Florida shortly after launch. The team is also watching a front that will move over the area on Thursday or early Friday which will bring thunderstorms and heavy rain. This front could delay launch preparations that are planned for that time frame such as the retraction of the Rotating Service Structure. However the team can delay these activities for several hours before they would need to postpone the launch.
Another important factor for Endeavour's launch is the on-time liftoff of the Russian Progress M10-M on Wednesday, April 27 at 9:05 a.m. EDT from Kazakhstan. If the Progress launch slips for a day, Endeavour has to stay on the pad for one additional day as well. Also, the Progress has to dock on schedule in order to clear the way for Space Shuttle Endeavour. Docking should occur 10:29 a.m. EDT on Friday.
Endeavour’s launch window extends from April 29 to May 4. The launch team plans to have 4 launch opportunities during these six days, however they will decide whether they go for a 24-hour or 48-hour scrub turnaround based on how far in the countdown the scrub occurs. NASA Test Director Jeremy Graeber noted that the team would aim for a 24-hour turnaround if the countdown is aborted prior to the L-4-hour mark. After that they would go for 48 hours, but they will decide when they get that far. Endeavour has another launch opportunity on May 8 if the Atlas V currently targeted to launch on May 6 lifts off on time. The next window opens on May 10 and will stay open until late May. But the teams are confident that they will get Endeavour off the pad during their first window of opportunity.