Shuttle Carrier Aircraft arrives at KSC ahead of Discovery’s final journey

by Chris Bergin

Kicking off what will be a highly emotional period for the space program, NASA 905 – the remaining Shuttle Carrier Aircraft (SCA) – arrived at the Kennedy Space Center (KSC) on Tuesday, in preparation for the final rollout of Discovery at the weekend. Discovery will then depart from her home base for one final time atop of the SCA, to head to her retirement home at the Smithsonian.

Discovery’s final days at KSC:

Discovery retired as the fleet leader, a role she adopted from her fallen sister, Columbia, but a title she more than deserved after twice saving the Space Shuttle Program (SSP) by successfully completing the Return To Flight (RTF) missions after STS-51L and STS-107.

Her career span over three decades, finally drawing to a conclusion when she completed her final mission, STS-133, safely returning Commander Steve Lindsey and his crew to Earth.

Now spending her final days inside the Vehicle Assembly Building (VAB), with the lifeblood of her toxic fluids drained from her veins, she looks very much like she did when she landed after that final mission – and still sports the scars of her 39 victorious battles with the hostile environment of reentry.

While her new audience of tourists probably won’t notice the changes, some of her hardware was removed, allowing it to live on with the future Space Launch System (SLS) program.

She now sports Replica Shuttle Main Engines (RSMEs), allowing her noisy trio of Space Shuttle Main Engines (RS-25Ds) to transfer to the Heavy Lift Launch Vehicle – while some of her inners have been removed from her Main Propulsion System (MPS) for the same purpose.

Discovery’s sisters, Atlantis and Endeavour, have proven to be more generous donors to SLS, allowing Discovery one final fleet leader honor of ending her career as the “Vehicle Of Record” – much to the pleasure of Orbiter Flow manager Stephanie Stilson.

“I was little bit torn, because like Smithsonian (Discovery’s retirement home) I wanted to see Discovery kept intact. Discovery is my baby (and) I didn’t want to see anything happen to her, but I’m also torn because I do want us to have the ability to launch that next vehicle as soon as possible,” noted Ms Stilson to’s Philip Sloss during Discovery’s final move to the VAB.

“If using components off of the orbiters can help that happen, then we’re all for that, so I think we came to a good compromise in the sense of pretty much leaving Discovery as the vehicle of record. We didn’t take as much out of Discovery, but then we are taking out of Endeavour and Atlantis those components so that we can help SLS, so I think it was a good compromise between the programs.”

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When Discovery departs the VAB at the weekend, she’ll make that final roll to the Shuttle Landing Facility (SLF) on her own wheels for mating operations with the newly arrived SCA (NASA 905) – which safely landed at the Florida spaceport on Tuesday.

While Discovery will have no trouble mating with the SCA via the Shuttle Landing Facility’s Mate-Demate Device (MDD), a large amount of work was required to evaluate how to help her egress the modified 747, once the duo arrive at the world-famous Smithsonian.

“747 Sling build-up for offloading the orbiters at the museums was completed and heavy equipment transported the sling and Fly Away Kit Conex to the staging area at the MDD,” noted Discovery’s T&R notes (L2) last year. “The conex will be removed from the transport trailer and work will begin on crane build up to support of the Sling assembly and SIM Run.”

This planning was conducted under the guidance of the Management Integration & Planning T&R Readiness Reviews, which is utilizing onsite procedures with all the museums set to receive an orbiter – the first of which was held at the Smithsonian. Simulations were also conducted at the SLF last year.

“The fly away kit is a wind restraint system for use with portable cranes and the 743 sling when demating the Orbiter from the Shuttle Carrier Aircraft at a location that does not have a Mate Demate Device (MDD),” added the T&R notes.

“This is the setup that will be used when the Orbiters are ferried for delivery to the museum locations. No flight hardware, SCA, or mockups were involved in this test. The Fly away kit demonstration was completed with two successful lift cycles.”

The process will be elaborate, as shown in a new Transition and Retirement presentation acquired by L2 this week (See slides above, L2 Link to presentation), with notes to be published ahead of her trip north.

While the focus will be on both Discovery and Enterprise – the latter also looking forward to an eventful period as she makes way for Discovery’s arrival and prepares to head to New York – NASA 905 has a major role to play in safely delivering Discovery to her final resting place.

NASA 905 is now the only SCA in service, after NASA 911 made its final flight February 8, 2012. The latter’s final mission was a short flight lasting only about 20 minutes from NASA’s Dryden Flight Research Center at Edwards Air Force Base to The Dryden Aircraft Operations Facility adjacent to Air Force Plant 42 in Palmdale, California.

The 747 four-engine intercontinental-range, swept-wing “jumbo jets” entered commercial service in 1969, prior to being purchased by NASA to ferry orbiters cross-country.

The SCA sports three struts with associated interior structural strengthening protrude from the top of the fuselage (two aft, one forward) on which the orbiter is attached. They also have two additional vertical stabilizers, one on each end of the standard horizontal stabilizer, to enhance directional stability.

After NASA 905 completes its role with the orbiters, both SCAs will support NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) Boeing 747SP aircraft.

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

(Images: Via Philip Sloss/, L2 content and NASA)

(L2 and NSF are continuing to follow the orbiters through their transitional period. To join L2, click here:

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