All good things must come to an end. And thus was the grand finale of the Space Shuttle Program in 2011. It was year of exceptional highs and emotional scenes as Discovery, Endeavour, and Atlantis closed out their remarkable careers with same style, grace, mission success, and safety that all had come to know from them.
OV-103/Discovery – The final voyage of the veteran workhorse:
For the final year of the Space Shuttle Program, operations in 2011 began where all Shuttle missions have: in the Vehicle Assembly Building.
After enduring a rollback from LC-39A in late-December 2010, because of cracks on the stringers of her External Tank’s (ET) intertank structure, Space Shuttle orbiter Discovery, OV-103, spent the first month of 2011 in the VAB undergoing ET intertank repairs and strengthening activities while the various NASA centers conducted numerous simulations to nail down the cause of the ET stringer cracks. (L2 Link).
Discovery, the third operational Shuttle orbiter and fourth overall Shuttle orbiter constructed by NASA, was preparing for her 39th and final mission in November 2010 when the stringer crack issue presented itself during the mission’s first launch attempt on November 5, 2010.
Following the discovery of this issue, NASA mission managers refused to set a launch date for the flight in a concerted effort to allow the engineering analysis teams to have the time they needed to properly and safely address the issue without feeling a push toward launch fever.
STS-133 Specific – Including ET Stringer Issue – Articles: http://www.nasaspaceflight.com/tag/sts-133/
On January 4, NASA identified the potential root cause for the stringer issue – a mottling on the stringers themselves.
As noted by an investigation report, “Some material used for the stringers was found to be ‘mottled,’ with a different surface appearance than the standard material. Testing revealed this mottled material had lower fracture toughness than the nominal material and exhibited unstable crack growth.
“All of the cracks found during tanking as well as cracks fixed during manufacturing were located on stringers made with this mottled material.”
Furthermore, engineers were finally able to recreate the stringer crack failure seen on Discovery’s ET using the stringers from the partially-built ET-139 at the Michoud Assembly Facility (MAF).
By January 6, the all-powerful Program Requirements Control Board (PRCB) had directed teams to proceed forward with the radius block modification on well over 100 of Discovery’s tank stringers – a decision that further emphasized the drive for safety and understanding over launch date pressure.
With that, Discovery’s launch date was penciled in for February 24 or 25 as negotiations began with other ISS partners – specifically ESA (the European Space Agency) which was planning to dock their ATV-2 vehicle to the ISS at the same time that Discovery would now be ready for launch.
After negotiations concluded, it was decided that ATV-2’s docking on the morning of February 24 would permit the launch of Discovery later that day – something that had previously been ruled out due to communication and on-orbit requirements of the two vehicles and the ISS crew.
But as repairs to Discovery’s stringers kicked into high gear and things looked to be settling out for the veteran space vehicle, STS-133/Discovery crewmember Tim Kopra was injured and had to be removed from the mission as a result.
Within three days, Steve Bowen was assigned to the mission as Tim Kopra’s replacement, and NASA, in making the crewmember switch announcement, made it clear that Bowen’s experience on the previous Shuttle mission, STS-132/Atlantis, meant that he would need only moderate refresher training to perform the EVA activities originally assigned to Kopra.
As a result, Discovery would keep her February 24 NET launch date, and Nicole Stott and Al Drew would split the Flight Engineering responsibilities for launch and entry that Kopra was originally assigned.
On the night of January 31/February 1 – the 8th anniversary of the loss of sister Columbia – Discovery was returned to the launch pad for what would be the 20th post-Columbia mission.
By all would not be as smooth sailing as hoped. The GUCP once again showed its temperamental side by failing an ambient leak check at the pad. (L2 Link).
The GUCP was disassembled, inspected, its two-part flight seals replaced, and reassembled. Subsequent ambient leak checks revealed a healthy GUCP, and all pad activities continued on schedule.
On February 15, the Ariane 5 launch vehicle successfully delivered the ATV-2 ESA resupply vehicle for the ISS into orbit – paving the way for a 24 February docking of ATV-2 to ISS and subsequent launch of Discovery later that same day.
With all approvals in place, the three-day countdown began on Monday, February 21.
The countdown proceeded flawlessly, and fueling of Discovery’s External Tank yielded absolutely no issues with the modified stringers or the GUCP.
Following the successful docking of ATV-2 to the ISS on the morning of 24 February, final preparations continued, the crew boarded Discovery, and the Countdown reached T-9mins and holding.
And then… it happened: the Eastern Range suffered a computer anomaly that prevented them from seeing the necessary safety information readouts from Discovery.
As the Range team worked the issue, the minutes continued to tick toward the end of the day’s short launch window.
With concurrence from all involved, Discovery’s Commander, Steve Lindsey, told the millions watching to “get ready to witness the majesty and the power of the Shuttle Discovery as she lifts off one more time.”
The launch countdown picked up and was indeed held at T-5mins for just over 3mins as the Range continued to work the issue.
In a heart-pounded final seconds, the launch team moved, with esteem calm and professionalism, to resume the countdown in time once the Range issue was cleared.
In the end, the team successfully resumed the countdown with only 1 second of LOX drain back hold time – the limiting launch window factor that day – remaining before a scrub would have had to have been called for the day.
But that one second was all that was needed.
To thunderous applause, numerous tears, an on-hand spectator number reaching close to a quarter of million people, and under crystal clear skies, the Space Shuttle Discovery began the display she and her sisters were best known for when she gracefully lifted off from LC-39A at the Kennedy Space Center at 1653.24 EST and made one final reach for the stars.
A true tribute to America’s space workforce, Discovery executed a flawless ascent and safely, successfully, and with pride delivered her six-member crew and mission payload to LEO.
With her docking, a historic milestone was reached for the ISS – a complete family moment with the ISS supporting all of its support vehicles: Shuttle, Soyuz, Progress, HTV, and ATV.
During the mission, Discovery delivered thousands of pounds of external spares via the Express Logistics Carrier ELC-4 and thousands of pounds of internal supplies for the Space Station via the newly minted Permanent Multipurpose Module (PMM) Leonardo – a former Multi-Purpose Logistics Module (MPLM).
The addition of PMM Leonardo marked the final, permanent, pressurized module to be delivered to the ISS by the Space Shuttle fleet and NASA.
After nearly nine days of joint-docked operations, the ISS bid a final farewell to Orbiter Discovery after 13 missions to the orbital outpost.
She was also the oldest-surviving Shuttle orbiter in the fleet upon completion of her final mission as well as the first Space Shuttle orbiter to successfully complete every single one of her missions – including all three Return to Flight missions following the losses of her big sisters Challenger and Columbia.
Discovery’s service to the human race began on 30 August 1984 with the launch of the STS-41D mission and ended on 9 March 2011 having lasted 26 years 6 months 6 days and 39 missions.
OV-105/Endeavour – An emotional high for the baby of the fleet:
For Endeavour, the 2011 calendar year began with direct knock-on effects from the on-going stringer crack issue of her sister Discovery’s ET.
The Space Shuttle Endeavour, the fifth and final space-worthy orbiter and sixth and final overall Space Shuttle orbiter constructed by NASA, began 2011 in her OPF-2 home as NASA hammered out a fix to the stringer issue on the External Tank.
Following the identification of root cause of the issue and implementation of the radius block modification, NASA made the decision to modify ET-122 – the External Tank Endeavour was to use on her final mission – despite the fact that ET-122 was an earlier-constructed tank than Discovery’s and was not constructed from the same material batch as Discovery’s mottled stringers were.
Nonetheless, the decision was made to ensure the highest safety factor for Endeavour and her returned-to-service ET.
In many ways, Endeavour’s final journey to space was a story of perseverance and rising above the odds.
Endeavour herself had always been a symbol of triumph from the throes of tragedy as her existence is owed entirely to the loss of Challenger, the sister she never knew.
Called upon for multiple important missions during her storied career, Endeavour was the Space Shuttle Orbiter that saved the Hubble Space Telescope in 1993 and the Orbiter that began construction of the International Space Station in December 1998 when she launched on the STS-88 mission to join the US’s “Unity” module with Russia’s Zarya module.
For Endeavour’s final mission, her Commander was none other than veteran Shuttle flier Mark E. Kelly – who, like his vehicle, was an amazing source of strength, hope, and inspiration throughout the early months of 2011 and throughout the STS-134 mission.
But the perseverance on STS-134 did not end with Endeavour or her crew. Despite the fact that the STS-134 mission was the first of the final two missions to be added to the end of the Shuttle manifest (and the first of the final Shuttle missions whose flight was specifically mandated by Congress), her External Tank was a major source of pride for the NASA workforce.
Built in 2002, ET-122 was damaged during the landfall of Hurricane Katrina near the New Orleans MAF construction facility for the tanks. In fact, ET-122 was so damaged by the hurricane that it was completely removed from flight status.
Originally, Endeavour’s mission was supposed to use ET-138 – the final completed External Tank in the numerical sequence.
However, the addition of the STS-335 Launch On Need rescue mission for Endeavour mandated the need for another tank. Rather than complete fabrication and assembly of a new tank, ET-139, the MAF workforce was directed in November 2008 to restore ET-122 to flight status.
In addition to all the hurricane repair work that needed to be made, MAF workers also had to implement most of the RTF (Return To Flight) modifications mandated by NASA in the wake of the Columbia accident.
By early 2011, NASA decided to move ET-122 to STS-134/Endeavour’s mission so that Atlantis, if the STS-335 rescue mission was needed, could fly with a perfectly clean tank instead of the patched-up, but extremely safe, ET-122.
With a rather traumatic opening week to her last visit to Pad-A, Endeavour’s flight managers were forced to review TPS damage zones on the baby of the Orbiter fleet after a tool was accidentally dropped from the RSS (Rotating Service Structure) and impacted Endeavour before landing on the zero-level deck of the MLP (Mobile Launch Platform).
The damage was very minor and no repairs were carried out on Endeavour.
At this time, as well, Endeavour was also cleared to proceed toward her April 19 launch date when Russian space officials confirmed that their Soyuz launch would only be slipping to April 4 and not deeper in April like originally thought.
But by the end of March, Russia and NASA were once again into negotiations on Endeavour’s launch date as a conflict between Russia’s Progress M-10M spacecraft and Endeavour’s missions arose.
Endeavour eventually lost the fight and was forced to move to an April 29 launch date – which she continued processing toward despite multiple rounds of adverse weather at the launch pad that triggered evaluations of the stack for storm damage.
Also at this time, NASA managers decided to cancel plans for a Soyuz fly-about of the docked Endeavour/ISS stack because of crew impact concerns should the Soyuz fail to re-dock to the ISS. (L2 Link).
By April 13, NASA formally extended Endeavour’s swan song mission by one day. With a newly extended mission, Endeavour entered what was thought to be her final launch countdown on April 26.
On launch day, as Endeavour’s crew prepared for their journey to the launch pad, an APU-1 heater issue presented itself. Initial attempts to troubleshoot the issue did not prove successful, and Launch Director Mike Leinbach scrubbed the April 29 launch attempt.
In the following week, the APU-1 heater issue was quickly traced to the Aft Load Control Assembly (ALCA-2) box. The ALCA-2 was Removed and Replaced, where a blown driver was subsequently focused on as the cause of the heater issue. (L2 Link).
For the final time, the countdown for the launch of Space Shuttle Endeavour began on Friday, May 13.
Thanks to the delay in the launch date, and agreements with Russia to undock the Soyuz TMA-20 for a nominal end of Soyuz mission landing during Endeavour’s docked mission, the formal plan to use the departing Soyuz to capture imagery of the docked Endeavour/ISS stack returned to mission planning.
On May 16, even though the weather looked borderline at best, all launch commit criteria aligned, leading to a final, unanimous “GO” for launch decision.
From the cockpit of Endeavour, Commander Mark Kelly said, “We endeavor to build a better life than the generation before and we endeavor to be a united nation. It is in our DNA to reach for the stars and explore. We must not stop.”
And mere minutes later, under overcast, grey, dreary skies, the Space Shuttle Endeavour roared to life for the 27th and final time as she thundered from the launch pad to begin her 25th and final voyage.
To many on the ground, including the launch team, Endeavour seemed to take just a little longer than normal to rise from the launch pad, turn, and begin her historic final mission to space – giving the 500,000 to 750,000 people in personal attendance the feeling of being able to see her for just a bit longer in all her glory.
Her launch was a moment of historical coincidence as well. Endeavour lifted off for the final time exactly 19 years to the day (May 16) after she landed to conclude her maiden voyage, the STS-49 mission in May 1992.
Her mission marked the delivery of the premiere and exciting Alpha Magnetic Spectrometer to the ISS – an experiment designed to search for evidence of the existence of dark matter, anti-matter, and dark energy in our universe.
The mission also saw the delivery of ELC-3 – the final large delivery of external spares for the ISS – to the Station.
And, as we all remember and cherish, the mission also provided the stunning photography and video of Endeavour docked to the International Space Station from the vantage point of the departing Soyuz spacecraft. (L2 Link to 271 hi res flyaround photos)
But the greatest milestone of all came toward the end of Endeavour’s docked mission: US Assembly Complete of the International Space Station – achieved when Endeavour’s crew transferred and berthed Endeavour’s OBSS (Orbiter Boom Sensor System) to the orbiting outpost.
Thus, Endeavour was the orbiter that began and completed US assembly of the International Space Station.
(Animated image resized from hires/full screen version and sequence photo dumps on L2′s STS-134 Flight Day image section – several hundred megabytes strong – L2 Link.)
After 11 days 17 hours 41 minutes of docked operations with the ISS, Endeavour bid a fond farewell to her orbital child.
Two days later, under the cover of darkness, Endeavour gallantly swooped down over her Florida home to end her career on 1 June 2011 at 0235 EDT.
To the very end, Endeavour was and always will be an iconic symbol of hope, a ship that inspires pride, awe, the quest for knowledge, and the determination to pick ourselves up and continue forward when adversity would rather us surrender.
After 19 years 24 days 6 hours and 55 minutes of service (May 7, 1992 at 1940 EDT to June 1, 2011 at 0235 EDT), Endeavour officially ended her tenure with the Space Shuttle Program. But she still remains our hope for a new tomorrow, an era when humans will regularly explore the space beyond the confines of our home world and push our boundaries of scientific knowledge and our quest of exploration.
OV-104/Atlantis – The Grand Finale of an American icon:
STS-135: The flight that wasn’t even manifested at the start of 2011.
Included in the NASA Authorization Act of 2011, which was signed into law on 11 October 2010, funding for the STS-135 mission remained in limbo while Congress remained incapable of reaching an agreement on the exact nature of the Fiscal Year 2011 calendar budget.
To this end, NASA continued procurement of mission hardware and software for the STS-335 contingency LON rescue mission which would have been used in the event that Endeavour became disabled during STS-134.
On 20 January 2011, NASA officially changed the mission designation number for STS-335 to STS-135 on internal documentation only (L2 Link), allowing teams to proceed with mission training and planning operations so that the continuing appropriations battle in Washington D.C. would not impact flight operations.
Finally, on 13 February 2011, NASA announced and confirmed that STS-135 would fly to the International Space Station regardless of whether or not appropriations from Congress materialized.
At this point, STS-135 became an officially manifested flight, making it one of the quickest missions to go from manifestation to liftoff in Shuttle Program history.
Undergoing a near one-year OPF-1 flow for STS-335/135, Space Shuttle orbiter Atlantis was mated to her ET/SRB stack.
Arriving at the launch pad at the same time as her sister Endeavour landed a few miles away to complete her last mission on June 1, Atlantis began a one month eight day pad flow.
On 15 June, a tanking test was performed on the Atlantis/STS-135 stack to confirm a solid fix to Atlantis’s Tank’s stringers – which underwent the same modifications as Discovery’s and Endeavour’s tanks had.
The Tanking Test revealed a healthy tank and modified stringers while also revealing a hydrogen fuel valve issue in Main Engine #3 that, if it had occurred on launch day, would have resulted in a multi-day scrub.
Replacement of the valve was completed on 21 June, just one day after Atlantis’s payload was installed into her payload bay.
Despite a dismal weather forecast with only a 40 percent chance of acceptable weather, NASA launch managers decided to proceed with the launch attempt on 8 July.
Tanking operations began right on time at 0201 EDT and wrapped up three hours later with no issue.
In fact, Atlantis performed flawlessly during her countdown, with the only concern being the weather.
One hour before the scheduled liftoff, weather conditions improved and went GREEN, falling within Launch Commit Criteria rules. However, post-flight launch weather rules governing Return To Launch Site (RTLS) abort weather requirements could not be satisfied by the strict by-the-word standards.
However, the commitment clause for “Good Sense” allowed Launch Integration Manager Mike Moses to issue a formal waiver for the RTLS weather restrictions – giving all stations a GO status for launch – since the weather violation would have cleared by the time of an RTLS landing.
After Launch Director Mike Leinbach wished the crew “Good luck … on the final flight of this true American icon,” the countdown resumed and proceeded nominally from T-9mins to T-34seconds.
At T-34seconds, the Ground Launch Sequencer issued an automated hold at T-31seconds and inhibited Atlantis’s onboard computers from taking control of the countdown.
Prior to this, the final mission of the Space Shuttle to the ISS, the last time a Shuttle launch countdown was held at T-31secs was on the STS-88 mission – the very first Shuttle mission to ISS.
For Atlantis and STS-135, the hold was issued due to the failed indication of a complete retraction and latch of the Gaseous Oxygen vent arm.
The launch control team, one final time, demonstrated their extreme commitment to safety and professionalism as they calmly worked through the issue and used close circuit TV cameras at the launch pad to verify that the GOX vent arm was indeed fully retract and latched against the FSS (Fixed Service Structure) – thus confirming that the failed retraction and latching indication was a sensor error.
The glitch was ironic in many ways, as the GOX vent arm had never given the launch team an issue during the 150+ countdown retractions it was placed through during the life of the Program.
Furthermore, the GOX vent arm was a complete afterthought for the Shuttle Program and was only installed on the FSS after pad validation testing using test Shuttle Enterprise in 1979 revealed the need for the arm and vent system to prevent the build-up of dangerous ice at the top of the External Tank during the countdown.
STS-135 Specific Articles: http://www.nasaspaceflight.com/tag/sts-135/
With the issue resolved, the launch team released the hold, and Atlantis’s onboard computers took control of the vehicle and countdown. The time was 11:29:03.9 EDT on 8 July 2011.
In front of a world-wide audience and crowd of one million people at the Kennedy Space Center and surrounding cities and beaches, the Space Shuttle Atlantis came to life, majestically rose from her seaside launch pad, stretched her wings one final time, and went transonic as she punched through the cloud deck and disappeared from view – leaving only the sound of her engines as evidence of her flexing her muscles for the last time.
Atlantis, like her sisters, delivered her crew safely to orbit and docked to the ISS for the final time on 10 July 2011.
The mission saw the Atlantis crew deliver thousands of pounds of internal spares and supplies to the Station – stockpiling the outpost for several years to come.
On the final full day of docked operations, Atlantis Commander Chris Ferguson – at the farewell ceremony on the ISS – presented the ISS crew with a small American flag that was flown on the STS-1 mission by Shuttle Columbia on April 12-14, 1981.
The flag was fastened to the inner wall of the ISS and flanked by the STS-1 and STS-135 mission patches – a symbolic gesture signaling the end of the Shuttle program.
On July 21, Atlantis navigated her way through the fierce outer atmosphere of Earth, taking aim on the Kennedy Space Center for a pre-dawn landing on runway 15.
(Animation created from some of the 114 hi res photos (all available in L2) taken by Mike Fossum on the ISS)
Less than 10 minutes before landing, the ISS made a breath-taking visual pass directly over the Kennedy Space Center in a final salute to the Shuttle Program, heralding Atlantis’s arrival to her permanent home city.
At 05:57:54, Atlantis descended from the darkness and touched her wheels to the pavement at the Shuttle Landing Facility for an emotional finale to her legacy and the legacy of the Space Shuttle Program.
Upon “wheels stop,” the final Shuttle Commander thanked all the men and women who worked on the program and the vehicles over the preceding 30+ years. And in a touching moment, Commander Ferguson also thanked the five flight vehicles themselves for protecting their crews and enabling the expansion of our knowledge and quest for science.
Less than 30 minutes after landing, Atlantis fell silent for the final time.
It was over.
Final Reflections on a legend:
With that final Shuttle landing came a moment of joy, sadness, grief, prolonged contemplation, but above all PRIDE in an amazingly complex set of vehicles that inspired countless numbers around the world, flew more people to space than any other spacecraft thus far (and for many, many decades to come), and helped bridge the gap between nations and forge unprecedented alliances in space.
For 30 years, 3 months, 8 days, 22 hours and 57 minutes (April 12, 1981 at 0700EDT to July 21, 2011 at 0557 EDT), the five space-worthy Shuttle orbiters spent a combined total of 1,332 days 1 hour and 36 minutes in space, completing 21,152 orbits of Earth over 548.2 million miles.
All five Shuttle orbiters deployed a combined total of 66 satellites, completed 46 rendezvous with an orbital space station (9 to MIR and 37 to ISS), and carried a combined total of 827 crewmembers (some more than once) into space.
For the final breakdown:
Discovery (OV-103): 39 missions; 365days 12hrs 53mins in space; 5,830 orbits of Earth; 148.2 million miles travelled; 31 satellites deployed (including the Hubble Space Telescope); 14 space station dockings; 252 crewmembers.
Atlantis (OV-104): 33 missions; 305days 7hrs 47mins in space; 4,848 orbits of Earth; 125.9 million miles travelled; 14 satellites deployed; 19 space station dockings (a world-wide record she will keep for decades to come); 207 crewmembers.
Columbia (OV-102): 28 missions; 300days 17hours 41mins in space; 4,808 orbits of Earth; 125.5 million miles travelled; 8 satellites deployed; 160 crewmembers.
Endeavour (OV-105): 25 missions; 299days 3hrs 19mins in space; 4,671 orbits of Earth; 122.8 million miles travelled; 3 satellites deployed; 12 space station dockings and one space station rendezvous and grapple; 148 crewmembers.
Challenger (OV-099): 10 missions; 62days 7hrs 56mins in space; 995 orbits of Earth; 25.8 million miles travelled; 10 satellites deployed; 60 crewmembers.
And while the Shuttles’ missions are behind them, and their engines and APUs forever silent, we wish them and all who have flown aboard them, and all who have worked on them, and all who dedicated theirs lives to making them fly Godspeed in whatever the future may hold.
The Space Shuttle Program, the five orbiters, and their dedicated workforce leave behind an unprecedented legacy of achievement – and a legacy that must never be forgotten, a legacy where all were taught by example “To strive, to seek, to find, and not to yield.”
But moreover, the five Shuttle orbiters made a thousands-strong workforce incredibly proud.
To all of the NASA engineers, all of the astronauts, the entire NASA workforce (including those contractually employed by Pratt & Whitney, Boeing, ATK, Lockheed, USA), and all those whose names we never heard but nonetheless worked silently and many times without recognition in support of a program that you whole-heartedly believed in, we give you our resounding thanks and gratitude.
Without you, this program would not have been what it was.
The Shuttle program has come to an end, but the legacy of the program and those who worked and flew aboard the Shuttle, as well as those who will continue the dream of human space exploration, will forever carry on.
And so, for the final time, to Enterprise (1977-1985), Columbia (1981-2003), Challenger (1983-1986), Discovery (1984-2011), Atlantis (1985-2011), and Endeavour (1992-2011), you will always have our eternal thanks and gratitude for all that you have enabled the human race to learn and discover about not only the universe and our home planet, but also about ourselves and our ability to work together to achieve common and mutually-supportive objectives.
It was an incredible journey. And those of us who were a part of this great program, no matter how small a part, will never forget a single part of it or the Orbiters and people who made it all possible.
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To read about Atlantis and her sisters – from birth, processing, every single mission, through to retirement, click here for the links:
Click here for the amazing MaxQ Entertainment STS-135 Mission Review Music Video:
(Images: Via Larry Sullivan and Brian Papke, MaxQ Entertainment/NASASpaceflight.com, L2 and L2 presentations and NASA. To join L2, click here: http://www.nasaspaceflight.com/l2/)