Endeavour falls silent, but her accomplishments live on

The youngest orbiter in the shuttle fleet, Endeavour, was powered down for the final time this month, as she heads into the final stages of being prepared for shipping to her final resting home in California. Endeavour was put to sleep just days prior to the one year anniversary of her final launch, STS-134, a mission that continues to produce exciting science via the AMS-02 payload.

Endeavour was born out of tragedy, a little over one year after the loss of the sister she never knew, Challenger, following the STS-51L disaster.

With the decision not to upgrade Enterprise, instead taking advantage of structural spares created during the construction campaigns of OV-103/Discovery and OV-104/Atlantis, construction of NASA’s newest orbiter, known officially as OV-105 (Orbiter Vehicle 105), gained a significant time advantage.

To this end, the start of structural assembly of OV-105′s Crew Module began on February 15, 1982 – over five years before authorization to build OV-105 was issued.

The contract to build NASA’s newest, and last, Space Shuttle orbiter was issued to Rockwell International on July 31, 1987. Two months later, on September 7, engineers began assembling the body-flap of OV-105 – with assembly beginning on her aft-fuselage on Sept. 28.

She was powered-up for the very first time on July 6, 1990 – nearly 22 years before she was finally powered down for the final time.

Unlike all previous NASA spacecraft, NASA chose to involve, from the beginning, the general public when it came to choosing a name for the new Space Shuttle orbiter.

For the naming contest, students in all elementary and secondary schools in the United States were offered the opportunity to submit names for consideration.

The entries had to include an essay regarding the historical and exploratory significance for the suggested name, as well as information on why the name would be appropriate for the new Shuttle orbiter. State-level winners were selected and forward on for final consideration.

In the end, the name that was eventually chosen for OV-105 was the most popular entry received, accounting for one-third of the total state-level entry winners.

On April 25, 1991, the Space Shuttle orbiter ENDEAVOUR was proudly rolled out of her Palmdale construction facility by her dedicated workforce.

The Space Shuttle Endeavour is named after two great ships of exploration – the first being the HMS Endeavour, the ship Captained by James Cook on his first voyage from 1768-1771.

During the HMS Endeavour’s voyage, she transported Cook to the South Pacific where he observed and recorded the transit of Venus between the Earth and the sun – observations that helped early astronomers calculate the distance of the Earth from the sun.

With Endeavour transported to her new Florida home, preparations – including a Flight Readiness Firing (FRF) – were completed, ahead of her debut mission into space.

At 19:40:00 EDT on May 7, 1992, the countdown clock reached ZERO and the Solid Rocket Boosters ignited, lifting Endeavour and her seven-member crew off Pad-B and into the history books.

Launch of Endeavour and the STS-49 mission marked the first and only time that a Space Shuttle vehicle conducted its maiden voyage from Pad-B at the Kennedy Space Center; all four of Endeavour’s older sisters embarked on their maiden flights from Pad-A.

Once in orbit, Endeavour’s crew got right to work setting up for the rendezvous with the Intelsat VI satellite – which was stranded and unusable in Low Earth Orbit following its launch on a Titan rocket in March 1990 when its launch system failed to place it in its correct, geostationary orbit.

The crew also conducted part of an ongoing evaluation into the ASEM experiment for Space Station Freedom and performed Chimerical Protein Crystal Growth, Ultraviolet Plume Imager, and Air Force Maui Optical Station experiments/investigations.

The maiden voyage of Endeavour concluded at 06:57.38 EDT on May 16th – 20 years ago to the day- with a landing on runway 22 at Edwards AFB, CA. Upon landing, Endeavour made one more first for the Space Shuttle Program – the first use of a drag chute during landing.

Her final mission, STS-134, was the 165th manned U.S. spaceflight, the 134th Space Shuttle mission, the 25th flight of Endeavour, the 36th Shuttle flight to the ISS (Endeavour’s 12th), the 109th post-Challenger flight, and the 21st post-Columbia flight.

The mission marked the final spacewalks to be conducted by a Space Shuttle crew, the final time an international astronaut will fly on the Space Shuttle, the use of the final External Tank to be delivered to the Kennedy Space Center from the Michoud Assembly Facility in Louisiana, the final all-male crew of a Space Shuttle mission, the final flight of a major European Space Agency payload element on the Space Shuttle, and the delivery of the final major payloads to the ISS by the Space Shuttle.

But more importantly, Endeavour delivered the Alpha Magnetic Spectrometer -02 (AMS-02) and all the spares on ELC-3 (Express Logistics Carrier 3) marked U.S. Assembly Complete on the International Space Station, meaning that Endeavour became not only the orbiter to have begun construction of the ISS, but also the orbiter that completed U.S.-segment assembly of the ISS.

The anniversary of her launch, on May 16, 2011, was rightfully marked by grateful teams who benefited from the mission, not least the AMS-02 team, who continue to use the device for continuous observations of the universe, searching for evidence of and information on dark matter, dark energy, and anti-matter.

Her history, albeit one shorter than her older sisters, will continue to be taught to many generations to come, who will learn about her loyal service to her country and her planet, from saving Hubble, to building the ISS, through to bringing each and every one of her crews home safely.

Marking the end of her life as a powered vehicle, Endeavour was giving a respectful send off by the Kennedy Space Center (KSC) team, as they shut down her systems for the final time.

With teams in the Launch Control Center (LCC) Firing Room and onboard Endeavour herself, the reverse process for powering up an orbiter was carried out, relating to “waterfall” of activities such as switch off the power supplies, ground cooling, power bus controls and the Data Processing System (DPS).

Before this was carried out, a NASA TV video file showed the teams at work during this procedure, with one team member on the flight deck paying tribute to the orbiter and the teams before the final powerdown was completed.

“All of us up here on the flight deck would like to dedicate this final power down to all those that are not so fortunate to be here, to those that gave their blood and sweat to this program. The life of this orbiter will be down today, so to all those who can’t be here, we dedicate this to them.”

Another manager inside the Firing Room also added a few words, noting his sense of pride for the amazing team that for 40 years had been launching vehicles into space.

That was followed by the final procedures to power down Endeavour, marked by “here we go”, as the engineers flicked the power switches on the flight deck, turned off the monitors and finally, one by one, shutting down the AC bus sensors.

“AC Bus Sensor 3, is off,” being the final call from the flight deck of a darkened Endeavour.

Probably the most apt words came from Stephanie Stilson, NASA Flow Director for Orbiter Transition and Retirement, and United Space Alliance’s Walter “Buddy” McKenzie – who portrayed the love and care the workforce feel for the orbiters.

“You don’t want to see them go, you’re going to miss not having your hands on them every day, and knowing that you can really look out for them, but you’re happy for this progression of their career,” Stilson said to NASA.gov. “And you just trust that there will be other people there to take care of them and look out for them.”

Click here for additional T&R Articles: http://www.nasaspaceflight.com/tag/tr/

“You’re with them more than you are with your family. They actually become part of you,” McKenzie says of the shuttle fleet. “You work on them so much, you know where their weaknesses are and you know where their strengths are. You get familiar with them. At some point, they leave the machine stage, and they become part of your soul.”

Endeavour will now be put through the final stages of her Transition and Retirement (T&R) processing, ahead of being flown on the Shuttle Carrier Aircraft (SCA) to California. Her new home will be the California Science Center in Los Angeles.

To read about the orbiters –  from birth, processing, every single mission, through to retirement, click here for the links:

(Images: Via NASA, L2 Historical, L2 and special photography provided by Brian Papke, MaxQ/NASASpaceflight.com – many thousands of exclusive super hi-res image stock available on L2’s new Photo Section – 900+ gbs in size.)

(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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