Endeavour back home in OPF-2; final KSC work begins on the baby orbiter:

Since being relegated to VAB (Vehicle Assembly Building) HB-4 (High Bay 4) in August 2011 to allow sister Discovery access to OPF-1 to complete her retirement and decommissioning flow, Space Shuttle orbiter Endeavour has sat in the VAB to be viewed by spectators and visitors to the Kennedy Space Center – a role she will soon adopt full-time later this year.

After nearly six months in the VAB – a stay in storage longer then numerous of her OPF processing flows for her 25 flights – Endeavour’s engineers flocked to her side this morning for final preparations for her move back to her home in OPF-2.

With Endeavour (OV-105) safely cocooned inside the protective and processing structures of OPF-2, final decommission work will now proceed on the baby of NASA’s Shuttle fleet.

Serving her country and the world space community proud for just one-fourth of her total design life, Endeavour will now spend the next six months (at least) inside OPF-2 – the OPF that became her very own processing facility in 2003, following the tragic loss of her sister Columbia (OV-102) and her valiant international crew of seven men and women – the 9 year anniversary of which we remember today.

After vacating OPF-2 on 28 February 2011 for mating with her ET and SRB stack for her final voyage, Endeavour was taken into OPF-1 on 1 June 2011, following her successful return from the STS-134 mission.

In OPF-1, Endeavour was quickly deserviced from STS-134 flight status before being taken into full-up decommissioning operations – which saw her lose her three SSMEs (Space Shuttle Main Engines), OMS pods, FRCS (Forward Reaction Control System) pod, SRMS (Shuttle Remote Manipulator System) arm, and numerous pieces of internal equipment.

Stripped down and exposed, Endeavour was rolled out of OPF-1 on 11 August 2011 to make room for sister Discovery.

Since then, Endeavour has been stored in the VAB, with no work being performed on her during her stay in the VAB.

Following the removal of Space Shuttle orbiter Atlantis (OV-104) from OPF-2 on Friday, 20 January 2012 to make room for Endeavour, technicians in Endeavour’s home OPF have been busy performing Open Bay Work – scheduled maintenance and upkeep work on the OPF-2 systems that cannot be undertaken with a Shuttle orbiter present in the bay.

With that standard Open Bay Work complete, Endeavour will now take center stage in the OPF as technicians complete all open work for her eventual centerpiece display at the California Science Center in Los Angeles, California.

In addition to the installation of three Replica Shuttle Main Engines (RSMEs) into her aft, Endeavour will also receive her now-cosmetic-only OMS Pods and FRCS pod before having portions of her MPS (Main Propulsion System) removed for the SLS rocket and related program.

Significant work will also be conducted in the space underneath her Payload Bay as final efforts to completely safe Endeavour for public display are carried out.

Endeavour, however, will not receive her SRMS arm back. That arm, which enabled many of her accomplishments throughout her life, will be given to a Canadian museum – still to be determined – in acknowledgement of and thanks for Canada’s support for the Shuttle Program since its conception in the 1970s.

Like Discovery before her, Endeavour’s payload bay doors will then be closed for the final time and power cut to historic vehicle for the final time.

With power already terminated to former fleet leader Discovery and middle child Atlantis, Endeavour – despite having flown the penultimate flight of the Shuttle Program – will be the final surviving Shuttle orbiter once hooked back up to OPF power this week.

The most recent information indicates the Endeavour will be powered through mid-March, though with all T&R (Transition and Retirement) flow schedules in flux and under a certain degree of pressure to be finished quickly, it’s possible Endeavour could be powered down for the final time earlier than mid-March.

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

After this milestone is passed, she will then be fitted with a tailcone assembly to prepare her for her ferry flight across the country to the CSC.

While timelines are currently in flux because of the added work of having to remove MPS components from all three orbiters – work that has not yet begun on Endeavour or her sister Atlantis, KSC Orbiter T&R Manager Stephanie Stilson revealed in an interview with NASASpaceflight.com’s Philip Sloss that KSC is currently targeting a mid-September, 2012 ferry flight for Endeavour, as much as this has since slipped to the October timeframe.

The double switch - Atlantis to take Endeavour place in VAB HB4:

With Endeavour safely in her OPF, Shuttle orbiter Atlantis (OV-104) has now taken up residence in VAB HB4, which involved her being wheeled out of the VAB transfer aisle and around the side of the building to the HB4 entrance – a move which was delayed until next week, before being pushed back up to Thursday and completed in the afternoon.

This now become Atlantis’s temporary home for February and most of March while her big sister Discovery completes her final KSC processing milestones in OPF-1.

However, Atlantis’s stay in the VAB will not be as solitary as Endeavour’s proved.

Unlike Endeavour, which saw now work performed on her during her VAB vacation, Atlantis will undergo the beginnings of her MPS tear down and removal while in the VAB.

While timelines are not solidified yet based on ongoing MPS tear down and removal work on Discovery in OPF-1, Atlantis is expected to remain in VAB HB4 until mid- to late-March 2012.

At this time, once all work is terminated on Discovery, the veteran flyer will be removed from OPF-1 and rolled over to the VAB for her last few weeks at her Kennedy home – a place she has called home since 1983.

After OPF-1 is vacated, Atlantis will be wheeled into the processing facility for her final T&R work.

In mid-April, Discovery will be rolled on her wheels from the VAB, past her two sisters, and out to Shuttle Landing Facility where she will be picked up by the Mate-Demate Device and her wheels retracted up into her belly.

Discovery will then be mated to the Shuttle Carrier Aircraft and flown up the eastern seaboard of the United States to Washington, D.C. and the Smithsonian’s National Air and Space Museum on April 17, 2012 – 31 years 5 days after Columbia roared off Launch Pad 39A to begin this historic program.

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 NASA and L2 content – And special photography provided by Philip Sloss, NASASpaceflight.com and Larry Sullivan, MaxQ/NASASpaceflight.com – many thousands of super hi-res image stock available on L2′s new Photo Section)

(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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Atlantis is now expected to avoid a de-stack, following an engineering evaluation into potential requirements that would have favored the orbiter heading back to the home comforts of her OPF (Orbiter Processing Facility).

Those latest evaluations focused on the tire pressures – which naturally decay over time. Data shows the pressures will be acceptable for landing “as far away as April” – making a February launch target within spec.

Engineers will continue to monitor Atlantis’ health during the couple of months she’ll be housed in the VAB, with the option to call for a de-stack if it is deemed to be in her best interests.

Other factors include the possibility Wing Leading Edge (WLE) inspections may be required, Main Landing Gear (MLG) door seal compression measurements, and moisture levels on her Payload Bay Doors.

Most of Atlantis’ hypergolics have been offloaded, should the de-stack option be taken in the coming weeks. This mitigates the undesirable offload of large quantities of the hazardous hypers in the OPF, in the event of a rollover back to her barn.

“Integrated preps for rollback began last week and continued through weekend, following the SCAPE (Self-Contained Atmospheric Protection Ensemble) operation,” noted Monday processing information on L2, relating to the hypergolic propellant offload ahead of rollback.

During the offloading activities, one minor issue was noted with the pressures in the Left Reaction Control System (LRCS) tanks – which was mitigated by increasing the pressure in the associated helium tank.

“LRCS He Tank and LRCS propellant tank equalized. The Delta P should have been greater than 6 PSI for rollback to the VAB per OMRSD (Operational Maintenance Requirements and Specifications Document),” added Monday processing information.

“The He QD (Quick Disconnect) was mated to the vehicle, the manual valve was closed, and the tank was pressurized. S0072 operations then resumed. An OMRSD waiver was required for taking readings with the Heise gages on the panels.”

This action was called to avoid the potential migration of the hypergolic propellant into the pressurization system, which may of caused issues for required locking of the isolation valves.

Meanwhile, following an incident on Saturday, Atlantis’ tank – ET-127 - will also require engineering evaluations, due to what is currently being classed as ‘dings’ on the ET, caused by a liberated stainless steel support rod on Saturday.

Atlantis herself has avoided any serious damage to her TPS (Thermal Protection System) during the 3.5 foot long rod’s fall – which was later found on the floor of the MLP (Mobile Launch Platform).

“On Saturday morning a 3′ 1/2” stainless steel support rod that is used for the R/H FRCS (Right Hand Forward Reaction Control System) spill protection was found on the MLP “0″ Level between the Orbiter and ET (Inboard of the Left Hand Solid Rocket Booster),” noted processing information on L2.

“Initial inspections on the dropped tubing found several dings to the External Tank which could be possibly related damage from the tubing.

“Orbiter TPS personnel performed a preliminary inspection of the thermal protection system. The Orbiter was inspected from the 207 level down using binoculars. No Orbiter TPS damage was noted.”

The only remaining issue for STS-125 – relating to a faulty MDM (Multiplexer/Demultiplexer) card – will be mitigated by its replacement later this week inside the VAB.

“Troubleshooting on MDM OA2 was completed last week and indicated that the MDM has a bad port and will need to be replaced,” added processing information. “The plan is to replace the MDM in the VAB following the 1st power up of the vehicle, which is scheduled for Wednesday.”

The now-vacated Pad 39A will undergo preparations to receive Endeavour at the weekend, as she prepares for the November 14 launch of STS-126 to the International Space Station (ISS). Flight Readiness Review (FRR) based mission previews and processing will follow over the coming days.

L2 members: All documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size.

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