The final Space Shuttle lifted of from NASA’s Kennedy Space Center today at 11:29 a.m. EDT after a breath taking last phase of the Launch Countdown.
Countdown Operations entered the decisive timeframe yesterday. The Rotating Service Structure was rotated after it was delayed by about 2 hours due to an area of bad weather that moved over the Kennedy Space Center. Launch Pad 39A suffered two lightning strikes that had to be checked out by engineers to ensure the vehicle was in good condition. Launch Countdown operations continued overnight and the Launch Pad was cleared at 10pm EDT. Tanking began at 2:01am this morning – right on schedule. The tanking process went very well without a single issue. Atlantis however was not willing to let the launch team off the hook that easily. A valve inside the Left Orbital Maneuvering System closed automatically because the computer commanded it to close. Teams did not understand that at first and had to make sure they understand why the computer sent that signal. Launch rationale was re-established and the countdown was not impacted.
Weather was always a topic of discussion today. Meteorologists forecasted a 30% chance of good weather at launch time, but with the possibility of gaps in the cloud cover. That prompted the team to press on at the T-3 Hour mark. An issue with one of two liquid oxygen pumps gained the attention of the Launch Team for a brief period of time. Engineers switched to a backup pump and only lost 21 Minutes of stable replenish time on the oxygen side of the External Tank. Shortly before entering the 9-Minute Hold, the MILA Tracking Station had a software problem and technicians had to perform a software restart which added some exictement without threatening launch procedures. Inside the hold, meteorologists were busy advising the launch team on the observations and forecast models. It became clear that Range Weather would be GO for launch. RTLS weather remained ‘Observed Red’ meaning that Launch Commit Criteria was violated. Normally, that would cause the Shuttle to stay on the ground. Mission Managers came to the conclusion that the risk of flying through an area of precipitation in case of an RTLS Abort was acceptable due to the energy level the Shuttle would be flying at in today’s atmospheric conditions. The final poll before launch was positive – every station gave a GO to launch the final US Space Shuttle. The clock picked up at T-9 Minutes. At that point the automatic system, the Ground Launch Sequencer, takes control over the countdown and executes the final crucial tasks before liftoff. One of those is the retraction of the Gaseous Oxygen Vent Hood at T-2 minutes and 50 Seconds. At T-31 Seconds, the Ground Launch Sequencer hands over control to the Shuttle’s computer for the final steps of the countdown. This can only happen when the GLS is not tracking any issue/open items. Today, one indication was missing: The computer was uncertain wether the GOX Vent Hood was fully retracted and secured for launch, so the Handoff to Atlantis did not occur and the clock stopped at T-31 seconds. A failure was declared and the launch team already made plans for this case, as it appeared during test runs over the last couple of weeks. The issue was resolved and the GLS operator programmed the computer to restart the countdown and give control over it to Atlantis’ on-board GPCs. The final 31 seconds went as planned and Atlantis lifted off at 11:29:04am EDT – 1 Minute and 18 Seconds later than planned, but with 58 seconds remaining in the launch window, which according to a joke by Launch Director Mike Leinbach is “eternity” in the Launch Control Center.
The Ascent Performance of Atlantis was good, but not remarkable today. Several sensors showed erratic data during ascent and returned to normal values after the Main Engines cut off. These phenomena have appeared in previous missions and are well known by the team. The ride to orbit was safe for the crew at all times as all sensor systems have redundancy built in. The External Tank performed very well. No obvious foam liberations were detected and no items of interest came out of the initial review of the tape. These reviews will continue for several days and will include video taken by the solid rocket boosters that will become available when the SRBs are back later this weekend.
After Main Engine Cutoff, the crew began what could be a 13-day mission to the ISS. Initial reviews of the crygenics in Atlantis’ tanks revealed that the team already has 23 hours of margin. Various power saving steps will be taken to preserve more cryogenics, eventually allowing Atlantis to stay docked to the ISS docked for one additional day. A decision on that is expected by flight day 5.
After operations at the Kennedy Space Center finished. Mike Leinbach addressed his team with a few personal words wishing them Godspeed for the time after the Shuttle era. In the Vehicle Assembly Building, an event for Shuttle Workers was held. There was barbeque, beer and live music by Jimmy Buffet.
Roads around the Kennedy Space Center have been blocked for the hours following the launch of STS-135.
The 4-Person Space Shuttle Crew was woken up at 4:30am EDT to begin final Launch Preparations
Just before 7am EDT, the Crew began Suit Up Operations
The crew walked out of the Operations&Checkout Building at 7:35am EDT and began the 20-Minute trip to Launch Pad 39A aboard the Astrovan
The Kennedy Space Center was very busy today. NASA invited many special guests as well as 1550 journalists from all over the world
The Crew ingressed Atlantis and Rex Walheim became the last Astronaut to ever board a Space Shuttle. Travis Thompson, the leader of the Close Out Crew who has been a part of that crew for over 20 years, said a few very emotional words before every member of the Close Out Crew presented a sign to the camera, commemorating the final launch.