Space Shuttle Discovery: Thank you and goodbye

by Chris Gebhardt

The end of a legend. For 29 years, the Space Shuttle orbiter Discovery has lived and breathed her life at the Kennedy Space Center, Florida. She has been in every OPF, made over 50 trips to the VAB, been to the pad over 45 times, and launched with the hopes and dreams of her workforce and supporters 39 times. Now, she’s retired. Her engines forever silent – destined to be the centerpiece of the Smithsonian’s Air and Space exhibit for tourists visiting Washington D.C.

KSC Departure and arrival at Dulles International Airport:

After 29 years at the Kennedy Space Center, the veteran Space Shuttle orbiter Discovery (OV-103) and her workforce said their final goodbyes to each other before parting ways on Tuesday morning.

Already mated to the top of her SCA (Shuttle Carrier Aircraft), Discovery was flown under the power for her SCA off the Shuttle Landing Facility for the last time just after sunrise April 17.

After taking off, Discovery was taken on a circuit of her home, making low, 200-foot high passes over her launch pads, the VAB, OPFs, and various NASA buildings where her multitude of payloads and crews were processed/prepared for launch aboard her.

She was then flown over Cocoa Beach, in a low altitude flyby to allow those not at the Kennedy Space Center to see her one final time in Florida airspace and wave their final goodbyes. The backdrop was aptly stunning.

Discovery then ascended to cruising altitude for the multi-hour flight to the capital city of the United States of America.

Upon her arrival, she will be granted special permission – weather and security forces permitting – to violate the normal and long-standing no-fly zones over the nation’s capital, allowing her to fly over some of the more-famous national monuments and landmarks before turning toward Dulles International Airport.

Upon landing at Dulles, Discovery will be welcomed by a crowd of reporters, social media (mainly twitter) users, and Smithsonian employees who will then take charge of her.

Over the following two days, Discovery will be demated from the SCA, raised from the aircraft, and lowed onto her wheels on an off-to-the-side area of Dulles International.

On April 19, she will be towed from Dulles to the Udvar-Hazy facility of the Smithsonian where she will be placed on permanent public display in the Air and Space Museum – replacing her never-flown sister Enterprise.

Discovery – A tribute to the space workforce:

To some on the outside, she was just a machine – the third of five magnificent flying machines built by Rockwell International through contractual obligations for NASA. But to those who worked on her, who lived near her, who had the at times unbelievable opportunity to witness in person her majesty and awe, Discovery was so much more.

To her workforce and those who knew her – however slightly – she was a member of a family, a constant in many peoples’ lives.

From the moment she arrived at the Kennedy Space Center in November 1983, she was a star, a sparkling new orbiter ready to take her place alongside her two older sisters – Columbia and Challenger.

But even from the beginning, Discovery was a diva.

Rolled out to Launch Pad 39A for the first time on 19 May 1984, her Flight Readiness Firing (FRF) – a test to verify and certify her Main Propulsion System – was conducted in early June and verified that all was ready to go.

The date was 26 June 1984, and despite some rather dense fog at the launch pad, Discovery was cleared for lift off on her maiden voyage and the 12th mission of the Space Shuttle Program.

The countdown proceeded through the T-31 second mark, and Discovery’s five onboard General Purpose Computers (GPCs) took control of the countdown. The countdown clock continued to tick. The tension built. The excitement mounted. At T-10secs, the GLS (Ground Launch Sequencer – automated computer) was “go for main engine start.”

At T-6.6secs, a momentary roar as Discovery’s SSMEs (Space Shuttle Main Engines) came to life in preparation to help propel her to space – her home away from home.

But it was not to be that morning.

Within 0.2 seconds of the start of SSME-3 – the first engine in the sequence of three to be started, a fault in SSME-3 was detected by Discovery’s GPCs, which immediately ordered a cut off and abort to the launch sequence.

So quick was the reaction by Discovery’s computers, that the abort command was triggered before SSME-1 – the last engine to start in sequence – was given the start command.

The time difference between the start of SSME-3 and SSME-1 is only 0.24 seconds.

This quick response from Discovery’s computers initially caused confusion as the GLS and launch control team worked to verify that all three SSMEs had properly shut down. SSME-1 never gave a “shut down” indication because it never started to begin with.

In the minutes that followed, Discovery taught her first major lesson to her launch control team and revolutionized the post-SSME start RSLS (Redundant Set Launch Sequencer) abort procedures – including the need to immediately begin dowsing the aft engine compartment with water to prevent the flare up of hydrogen fires on the MLP (Mobile Launch Platform) deck following a post-SSME start RSLS abort.

Discovery herself was singed by a hydrogen fire in the minutes following the STS-41D pad abort.

Furthermore, the emergency escape systems on the pad were tested, modified, and upgrading to provide maximum safety for a Shuttle flight crew needing to evacuate the launch pad in a rapid fashion following a pad abort scenario.

This upgrade, despite numerous drills and practice before everything single Shuttle launch, was never needed over the life of the Program – a testament to the care, safety, service, and professionalism of all the workers who prepped the Shuttle fleet for flight.

After a rollback and engine replacement, Discovery’s STS-41D mission payload was reconfigured, new activities added, and a new launch date set.

Returned to the pad on 9 August 1984, Discovery’s third launch attempt was scrubbed on Aug. 29 due to a discrepancy noted in flight software of Discovery’s Master Events Controller relating to Solid Rocket Booster fire commands.

Launch was reset for the next day. After a 6min 50sec delay due to an aircraft in the vicinity, Discovery roared to life to the cheers of those gathered at the Kennedy Space Center and took to the skies for the first of what would ultimately be 39 times on 30 August 1984 at 0841.50 EDT.

Successfully making it to orbit, Discovery and her crew deployed three communications satellites and performed numerous scientific experiments on top of the normal on-orbit checkout procedures for a new orbiter.

After a highly successful 6 days 0 hours 56 minutes 4 seconds in space, Discovery landed safely at Edwards Air Force Base, CA – as all Space Shuttles were required to do on their maiden voyages – at 0937.54 EDT on 5 September 1984.

The following year saw another very important mission for Discovery: the STS-51D mission. Not only did this mission happen to launch on 12 April 1985 – the fourth anniversary of the first Space Shuttle flight (and the only Space Shuttle mission to launch on the Program’s anniversary) and the twenty-fourth anniversary of the first manned spaceflight – but it is also notable for one other reason: a tire blow out upon landing and rollout at the Kennedy Space Center.
 
After 6 days 23 hours 55 minutes 23 seconds in space, during which two communications satellites were deployed into orbit, an unscheduled EVA was performed in relation to one of those satellites, and numerous scientific experiments were performed, Discovery touched down at the Kennedy Space Center for the fifth Shuttle End Of Mission landing at the Florida spaceport.

During rollout, excessive braking forces combined with a roughly-grooved runway at Kennedy overstressed Discovery’s right Main Landing Gear, resulting in severe treading of one tire and the blow out of the second tire.

Nonetheless, Discovery rolled safely to a stop on the runway.

Expansive Discovery Review: http://www.nasaspaceflight.com/2011/02/workhorse-discovery-stands-ready-for-final-mission/

All future landings at the Kennedy Space Center were switched to Edwards Air Force Base, CA as the primary landing site until improved nose gear steering and a smoother runway at Kennedy could be engineered.

Sadly, Discovery’s next major mission would go down in history for a return from tragedy.

With the tragic loss of Space Shuttle Challenger – one of two of Discovery’s older sisters – and her STS-51L flight crew on 28 January 1986, NASA was forced to reexamine its culture of safety.

Following the Rogers Presidential Commission on the Space Shuttle Challenger Disaster, NASA set about implementing wide-spread safety upgrades to the now-three obiter Shuttle fleet (Columbia, Discovery, and Atlantis) and their propulsion components – most notably a large-scale modification of the Solid Rocket Boosters.

And NASA took its time, ensuring that every possible modification given the nature of the Space Shuttle vehicle was implemented.  It took two and half years.

But NASA would not give up… and neither would the United States. Recommitting itself to space exploration, the nation looked to NASA for recovery from Challenger.

On Independence Day (July 4) 1988, under a brilliant, bright sun, the Space Shuttle Discovery – a new symbol of hope and recovery – emerged from the VAB and made her way to Launch Pad 39B to prepare for the STS-26 mission.

Following a second Flight Readiness Firing (FRF) – one of only two Space Shuttle orbiters to require two FRFs (the other being her now-departed sister Challenger) – NASA again took its time to ensure that everything was in place for the historic and all-important Return To Flight (RTF) mission.

When everything was in place, the launch date was set for 29 September 1988.

Taking an extra 1hr 38mins on launch day to replace fuses in the cooling systems of two crew members’ new Launch and Entry Pressure suits and to discuss lighter winds aloft, all was ready.

As the countdown proceeded past T-2mins, a cabin pressure alarm sounded during the crew’s closing and locking of their pressure suit helmets and activation of O2 (oxygen flow) into their suits – resulting in a GLS call to hold at T-31secs.

The launch team quickly decided to “clear the air and reconfig” – thus solving the issue. The hold was removed before T-31secs and the countdown proceeded uninterrupted.

At 1137.00 EDT, one minute shy of the exact numerical time that Challenger had launched from the same launch pad two and a half years earlier, Space Shuttle Discovery came to life and lifted off on “America’s return to space” to the cheers and joyous calls from those in attendance at the Kennedy Space Center. 

Discovery performed a flawless ascent.

During the mission, the crew deployed the TDRS-C satellite, taking the place of the TDRS lost with Challenger on 51L.

Among the experiments performed on the mission was a Voice Control Unit which proved that the near-weightless environment of Low Earth Orbit caused fundamental changes in human speech.

After 4 days 1 hour in space, Discovery landed safely at Edwards Air Force Base, CA at 1237 EDT to complete the RTF mission and restore America’s manned presence in space.

Following the STS-26 mission, Discovery’s next big role – and arguably her most important mission to the scientific community was the STS-31 mission.

Launched 24 April 1990, Discovery overcame a last-minute hold at the T-31sec point to thunder off Launch Pad 39B for a 5-day mission to deploy the time-honored and famous Hubble Space Telescope.

Since its launch aboard Discovery, Hubble has provided invaluable scientific data and expanded humankind’s understanding of the universe and our place in it.

Immediately following her launch of the Hubble Space Telescope, Discovery was called upon during her next mission to launch the Ulysses probe to the study the sun.

Launched on 6 October 1990, STS-41/Discovery mission successfully deployed the Ulysses probe. Ulysses functioned from 1990 to 2009 and stands as one of Discovery’s longest-lasting contributions to science after the Hubble Space Telescope (1990-present day).

But Discovery was just getting started.

She was then tasked with launching the Upper Atmosphere Research Satellite (UARS). Launched at 1911 EDT on 12 September 1991 after a 14-minute non-standard hold at the T-5min mark due to a noise problem on the air-to-ground communication link, Discovery began the STS-48 mission.

She successfully deployed the UARS to study human effects on the Earth’s atmosphere and its shielding ozone layer. The flight was the first scheduled night landing at the Kennedy Space Center, but was diverted to California due to bad weather.

The mission was completed on 18 Sept. 1991 with a night-time landing at Edwards Air Force Base.

In 1994, Discovery was called to fly the STS-60 mission – the first U.S. manned mission to carry a Russian cosmonaut into space and the mission that BEGAN the Shuttle-MIR Program.

STS-60/Discovery launched from the Kennedy Space Center on 3 February 1994 at 0710.05 EST onto a 57-degree inclination orbit. The mission carried the Wake Shield Facility experiment and a SPACEHAB module into orbit, and carried out a live bi-directional audio and downlink link-up with the cosmonauts aboard the Russian space station MIR.

The mission lasted just over 8days 7hours and landed at the Kennedy Space Center on 11 February 1994 at 1418.41 EST.

Discovery’s MIR career would continue exactly one year later.
 
Following her inauguration of the Shuttle-MIR Program on STS-60, the Space Shuttle Discovery lifted off on her 20th mission exactly one year later. The STS-63 mission – the first Shuttle mission to rendezvous with the MIR space station – launched on 3 February 1995 at 0022.03 EST.

While the mission did not actually dock to MIR, it was the final test-bed mission before Shuttle-MIR dockings began in the summer of 1995 with sister Atlantis.

STS-63/Discovery marked another historical milestone: the first U.S. manned space mission to be piloted by a female; in this case, Eileen Collins. The mission was accomplished in 8days 6.5hrs and landed safely at the Kennedy Space Center on 11 February 1995 at 0651 EST.

While sister Atlantis trekked through the MIR missions, Discovery focused on getting ready for the construction of the International Space Station and solo-scientific flights to space.

For her next milestone mission, media attention was high – but nowhere near record – for her launch on the STS-95 mission.

Among the numerous historical moments were the launch of John Glenn (an original Mercury 7 astronaut, first American to orbit the Earth, and the oldest person to date to travel into space), the first Spaniard to fly into space, and the inauguration of HDTV broadcasting in the United States with live coast-to-coast coverage of the launch.

Discovery overcame a prolonged hold at T-9mins to discuss a Master Alarm due to cabin pressure at hatch closure, an unexpected hold at the T-5min mark due to an aircraft in the no-fly zone, a requested but ultimately unnecessary hold at T-31secs due to the same cabin pressure alarm, and a requested but ultimately unnecessary hold at T-31secs by the Range Safety Officer.

At Main Engine Start, the drag chute door detached and fell from the vehicle.

After all that, Discovery finally launched at 1419.34 EST on 29 October 1998. The mission lasted 8days 21hours and landed at the Kennedy Space Center on 7 November 1998 at 12:04pm EST. For this mission, Steve Lindsey piloted the veteran Shuttle orbiter.

Lindsey would ultimately Command Discovery on her final voyage 12.5 years later.

Seven months later, Discovery/STS-96 marked the first mission to dock with the International Space Station!

It was the start of a new era for Discovery, NASA, and the world community.

Originally scheduled to launch on 20 May 1999, the mission was postponed to 27 May when Discovery’s External (fuel) Tank was damaged by a hail storm on 8 May. The vehicle was disconnected from the pad and rolled back to the VAB for repairs on 16 May, marking the 13th rollback of a Space Shuttle stack from the launch pad.

She was returned to the pad on 20 May where launch processing resumed.

Launched at 0649 EDT 27 May 1999, STS-96 and Discovery performed the first docking to the International Space Station and the first space station servicing mission via the SPACEHAB module. The mission also delivered the Russian segment’s STRELA crane via the ICC (Integrated Cargo Carrier) in Discovery’s payload bay.

One spacewalk from Discovery’s airlock was performed during the mission.

After 9 days 19 hours in space, Discovery landed safely at the Kennedy Space Center at 0202.43 EDT. It was the 47th landing at the Kennedy Space Center and the 11th night landing of the Space Shuttle Program.

Discovery’s next mission would be a “call up” flight, STS-103: The emergency repair mission to the Hubble Space Telescope (HST).

Originally, NASA had planned to fly the HST Servicing Mission (SM) 3 in June 2000, but the failure of a third of six stabilization gyroscopes on the telescope mandated the consideration of a “call-up” mission to preserve the telescope.

Thus, NASA split the HST SM 3 mission in half and moved up the now-manifested HST SM 3A mission on STS-103 into October 1999. Severe fleet-side wiring problems discovered in 1999 prompted long delays to flights as engineers evaluated the Shuttle orbiter fleet’s hundreds and hundreds of miles of wiring.

Launch of STS-103 subsequently slipped from October to numerous dates in November before finally settling in early December.

Yet another wiring issue was then discovered which delayed launch from Dec. 6 to Dec. 9. During this, a dent was found in Discovery’s main propulsion system hydrogen line. The line was replaced, further delaying the launch.

The countdown finally began on Dec. 14 but was halted one day later due to the find of potentially improper welds on gaseous pressurize lines on the External Tank. This led to a larger concern of potential improper fuel line welds within Discovery herself. A paperwork review cleared the concerns and launch was reset for Dec. 18 which was scrubbed at T-9mins due to weather violations.

Liftoff of Discovery on the truncated STS-103 mission (due to the flight’s proximity to the end of the calendar year) finally occurred on 19 December 1999 at 1950.00 EST. Three spacewalks were performed on the mission (down from the originally scheduled 4) and restored Hubble to operating condition.

Discovery landed at the Kennedy Space Center after a one-orbit weather waive off at 1901.34 EST.

Next for Discovery was the 100th mission of the Space Shuttle Program.

An International Space Station (ISS) construction flight, Discovery and STS-92 lifted off Pad 39A on 11 October 2000 at 1917.00 EDT.

The 12-day mission delivered the Z1 truss segment to the ISS, Control Moment Gyros, Pressurized Mating Adapter 3, and two heat pipes to the Station.

The Z1 truss was the first permanent lattice work superstructure to be added to the ISS in preparation of the ISS’s first set of power gathering solar arrays, and PMA-3 was delivered to support future Shuttle dockings and the delivery of the US Destiny lab in 2001.

The 100th Space Shuttle mission landed safely at Edwards Air Force Base, CA on 24 October 2000 at 1659.47 EDT.

For Discovery, a major overhaul at the Kennedy Space Center beginning in 2001 would place her into an unwanted role she was all too familiar with: Returning the Shuttle fleet to active service following the loss of a sister orbiter.

At 0900 EST on 1 February 2003, Discovery, who was in pieces at the Kennedy Space Center undergoing an Orbiter Major Modification, became the oldest Space Shuttle orbiter in service when her only-surviving older sister Columbia lost her battle with Earth’s outer atmosphere.

In the two years that followed, Discovery, like her younger sisters Atlantis and Endeavour, received numerous upgrades in safety and flight assurance in the wake of the Columbia accident.

Through a fluke chance, Discovery was handed the all-important Return to Flight mission, STS-114, when Atlantis – the orbiter originally tasked with flying the 114 mission in both its original pre-Columbia form and post-Columbia form – was discovered to have a landing gear issue.

With safety at its highest levels in the course of the program, Discovery’s STS-114 launch date bounced around in the early/mid- 2005 timeframe before finally settling on 13 July 2005 after an External Tank swap in May/June 2005.

An Engine Cutoff (ECO) sensor issue on 13 July scrubbed the RTF launch and pushed it back to late-July as engineers worked to find the cause of the ECO sensor failure – a failure seen on the previous tank that prompted the tank swap.

The ultimate cause of the issue was never found and the problem did not reoccur on the subsequent launch attempt.

On 25 July 2005 at 1039.00 EDT – the EXACT numerical time that Columbia had launched two and a half years earlier on her ill-fated STS-107 mission (a coincidence made even more significant by the fact that Discovery’s 114 launch time was timed down to the millisecond based on ever-changing ISS orbital positioning) – Discovery lifted off with Eileen Collins at the helm.

The mission demonstrated the first-ever in-space repair of a Shuttle orbiter’s heat shield tiles, tested new in-flight repair techniques, and delivered much need food, supplies, and experiments to the ISS’s reduced crew of two.

However, the liberation of a large piece of thermal foam from the External Tank just after SRB separation grounded the Shuttle fleet for a full year as workers in Louisiana worked to make further modifications to the tanks and battle back from Hurricane Katrina.

Over the next three years, Discovery flew the second RTF mission from Columbia in July 2006 (the only Shuttle mission to launch on the United States’ Independence Day), preformed the first night launch following Columbia and the last Shuttle flight to depart Launch Pad-39B (STS-116), delivered the Harmony node module to the ISS (STS-120), brought up the premiere Japanese lab Kibo to the ISS (STS-124), delivered the final set of solar arrays to the ISS (STS-119), and flew a much-needed logistics mission to the ISS (STS-128).

Her longest mission would prove to be the STS-131 resupply and outfitting mission – the last Shuttle flight to launch with rookie astronauts, the last 7-member crew Shuttle mission, the last night launch of the Space Shuttle Program, and her 38th and penultimate mission.

Like her remaining sisters, Discovery did not go quietly into forced retirement.

Numerous delays because of flight order swaps, payload concerns, and mechanical/technical glitches/malfunctions pushed the final flight of Discovery from Sept. 2010 to Nov. 2010 to Dec. 2010 before finally landing in February 2011.

Following repairs and strengthening to her External Tank stringers, Discovery made her final trip to the launch pad on 1 February 2011 – 8 years to the day after the loss of her big sister Columbia.

The final month proceeded without incident.

Overcoming a nail-biting computer glitch with Eastern Range, Discovery proved on final time her command of attention, her beauty, her power, and her tribute to her workforce.

For the 39th and final time – and in front of a crowd 250,000 strong, Discovery lifted off Pad 39A at 1658.14 EST with only one (1) second remaining in the day’s launch window on 24 February 2011.

She gracefully ascended into a crystal clear Florida sky to say goodbye to a child she shared with sisters Atlantis and Endeavour: the International Space Station.

After 12 emotional days in space, Discovery eased onto the runway at the Kennedy Space Center, FL on 9 March 2011 at 1158.14 EST for the final moments her life.

Within 30 minutes of touching down, she fell forever silent – a vehicle that had more than half her operational life still left in her. A vehicle now relegated to the status of museum display piece when the county she served for 26 and a half years was nearly a decade away from having her successor crewed spaceship ready for use.
 
Final thoughts on a legend:

Borne at the conception of the Space Shuttle Program, Discovery was one of the instant stars of the Shuttle Program. The third-lightest orbiter in NASA’s fleet, Discovery’s career stretched 26 and a half years and resulted in a cumulative total of 365 days (one full calendar year) in space.

For much of that career, she was the fleet leader in terms of time in space and number of missions flown – a title she gained from older sister Columbia shortly after the RTF mission in 1988 (though Columbia and Discovery would occasionally swap front runner status in the 1990s).

At the end, she lived the final years of her life as the oldest surviving Space Shuttle orbiter and the undisputed leader of America’s space program.

Her accomplishment of flying to space 39 times is one that will not be broken for at least the next century – as no spacecraft in existence or anywhere near the drawing board will have the reusable capability that she and her sisters did.

She inspired us for two and half decades. She thrived in space. Her accomplishments in the unforgiving vacuum are what we remember her for.

She flew 39 missions, spent 365days 12hours 53minutes in space, orbited the Earth 5,830 times, travelled 148.2 million miles, deployed 31 satellites (including Hubble), performed 14 space station dockings (13 to ISS and 1 to MIR), and carried 252 crewmembers to the final frontier.

It is the last time we write about her. But we will never forget her accomplishments, the people who poured their hearts, souls, livelihoods into her, or what she represents.

To Space Shuttle Discovery, her crews, her engineers, her technicians, her launch teams, and her mission controllers – we THANK YOU for your unparalleled service, integrity, and work ethic.

What you have done will always be remembered and honored.

Sincerely,
The NASASpaceflight.com team.

To read about the orbiters –  from birth, processing, every single mission, through to retirement, click here for the links:
http://forum.nasaspaceflight.com/index.php?topic=25837.0

(Images: Via Larry Sullivan, Brian Papke, Nathan Moller and Steven Burgess – MaxQ Entertainment/NASASpaceflight.com, Ron Smith, L2 Historical (from 200-500mb of hi res images PER shuttle mission) and L2 content, plus NASA and NASA TV)

(L2 and NSF are continuing to follow the orbiters through their transitional period. To join L2, click here: http://www.nasaspaceflight.com/l2/)

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