One in, one out – Discovery and Endeavour tag for next mission

by Chris Bergin and Chris Gebhardt

Endeavour has safely returned to her Orbiter Processing Facility (OPF-2), following the highly successful STS-130 mission – which concluded on Sunday night with a safe landing at the Shuttle Landing Facility (SLF). Only hours after all three orbiters were reunited in the OPFs, Discovery bid her farewells and rolled over to the Vehicle Assembly Building (VAB), in preparation for her STS-131 mission in April.

STS-134 Processing Latest:

Endeavour is technically into STS-134 processing, although the coming weeks will concentrate on safing the vehicle, along with work on what is described as only a few minor dings to her Thermal Protection System (TPS). The current flow is known as “OPF Integrated roll-in ops”.

At least three windows are expected to be replaced, following the MMOD (Micro-Meteoroid Orbital Debris) events on orbit – although several windows are usually changed-out as a matter of course for a post-flight flow.

Engineers have only a few additional items to check as a result of Endeavour’s performance on STS-130, such as Fuel Cell 2’s instrumentation – which required a workaround after failing a self-test after undocking. All three Fuel Cells performed nominally during the mission – as did all of the orbiter’s systems, leading to high praise from the crew after departing the vehicle at the SLF.

STS-130 Specific Articles:

“STS-130 is complete, we’re safe on deck here at KSC, thanks to the work of a lot of people. Endeavour, my goodness, what a machine, she was perfect during the flight and we brought her back safe,” noted STS-130 Commander George Zamka, shortly after landing.

STS-134 will be the 133rd flight of the Space Shuttle Program (SSP) and the 25th and final voyage of the orbiter Endeavour, which began service in May 1992 on STS-49.

Carrying an ISS mission designation of ULF-6 (Utilization and Logistics Flight 6), STS-134 was officially baselined into the Flight Definition and Requirements Document (FDRD) on June 25, 2009 (several mission baselines available on L2) – initiating production of flight processes to support a No Earlier Than launch date of July 29, 2010.

AMS-02 – weighing 15,300lbs – will have four longeron payload latches and one active keel latch for its attachment to the payload bay sidewalls of Endeavour. Additionally, once on orbit, Remotely Operated Electrical Umbilicals (ROEU) will provide AMS-02 with 124V of power for its heaters and avionics. Prior to liftoff, this power will be provided via the T0 umbilicals on the launch pad.

These T0 umbilicals will also allow launch personnel to monitor the health of AMS-02 prior to liftoff and make sure that Launch Commit Criteria for the AMS-02 are not breached.

The AMS-02 unit, which was without a ride to orbit until the United States Congress mandated its addition to the Shuttle manifest, will be attached to the Starboard 3 Upper Inboard Command Attach System (CAS) on the ISS.

The AMS-02 unit is a “particle physics detector” which contains a large, cryogenic super-fluid helium superconducting magnet. The AMS-02 unit is designed to “search for antimatter and the origin and structure of dark matter.”

As noted in the main PRCB (Program Requirements Control Board) baseline presentation, AMS-02 is a complex payload that will require significant testing and payload processing before liftoff, and thus is the main “long lead” item for making the launch date.

Currently, the payload is expected to ship to the Kennedy Space Center (KSC) in May, pending extensive thermal vac testing. Concerns about the testing timeline were noted on PRCB documentation last year.

Making up the rest of the total payload mass of 36,740lbs is ELC-3, which will be carrying an Ammonia Tank Assembly, a Special Purpose Dextrous Manipulator Arm with Orbital Replacement Unit change-out mechanism, a spare ELC pallet controller avionics box, S-Band Antenna Sub-System #2 & 3, High Pressure Gas Tanks, and Space Test Program Houston 3 Department of Defense payload.

In addition to this manifested and baselined payload on ELC-3, the ISS program is looking at an additional 1,481lbs of payload that they would like on ELC-3 – payloads that are currently not listed on the mission baseline or accounted for in the mission’s up-mass weight – as the program attempts to get as much upmass to the ISS as possible prior to shuttle retirement.

Outside of OPF-2, work is already taking place on the boosters that will fly with Endeavour, as engineers ‘build up” the left Solid Rocket Booster segments prior to stacking.

“BI-144 / RSRM 112 Left Aft Booster build-up: Splice plate RT-455 application is complete and in cure. ETA Ring Pull Test and PDL Repair; Insta foam application failed pull test (Fwd side of ETA ring),” noted Monday processing information on L2. “Insta foam pull test is scheduled for 2nd shift tonight.

“Systems tunnel cable installation is in work. Aft IEA Installation; Task is on hold for acceptable Insta foam pull test. Strut Installation; Task is on hold for acceptable Insta foam pull test. Left Forward Center segment: Offload is scheduled for today.”

STS-131 Processing Latest:

Discovery was expected to rollover on Tuesday, following an official delay over the weekend, which was again confirmed by the NASA Test Director (NTD) on Monday morning.

“Orbiter: OV-103 (OPF Bay 3): Rollover to the VAB is planned for Tuesday at 0600 hrs. The orbiter is expected to be spotted in the VAB at 0800. S0008 Shuttle Interface Test Call-to-Stations is planned for 1700 on Friday.”

However, thanks to the smooth return of Endeavour to OPF-2, managers decided to push rollover back to Monday at short notice, with the process carried out before midday – as Discovery rode on the transporter  in the overcast conditions.

The rollover was also observed by the STS-131 crew, who took time to thank Discovery’s engineers for their work on the orbiter during the flow so far.

Discovery will deliver supplies to the International Space Station (ISS) via the Multi-Purpose Logistics Module (MPLM) Leonardo and the Light-weight Multipurpose Experiment Support Structure Carrier (LMC).

Secured inside the MPLM will be Zero-G stowage racks, an EXPRESS rack, a Muscle Atrophy Resistive Exercise (MARES) unit, a Window Observational Research Facility (WORF), one Crew Quarters Rack, a Minus 80 deg Laboratory Freezer for ISS (MELFI), Resupply Stowage Racks (RSRs), as well as Resupply Stowage Platforms (RSPs).

The launch date was delayed from March to April 5, due to a DDO (Dual Docked Operations) constraint relating to Soyuz TMA-18’s April 4 docking to the ISS. Discovery herself would have been able to support the original launch date, meaning she has been sat in OPF-3, waiting patiently for Monday’s rollover.

With over one week of contingency existing in the flow due to the launch date slip, engineers have also taken the opportunity to carry out additional plug pull tests on additional areas of Discovery’s External Tank (ET-135), following recent liberations from the intertank region during ascent.

That work has been completed ahead of Orbiter/ET mate inside the VAB’s High Bay 3 (HB-3), with the additional scaffolding now removed from around the tank.

“ET-135/SRB BI-142 / RSRM 110 (VAB HB-3): Left Tunnel Cover Closeouts; Need to paint after Orbiter Mate. Engineering walk down to be worked after Orbiter Mate. L/R FN #8 Cover RT-455/Instafoam application; L/R Insta-Foam applied Friday.

“ET-135-TS-009. Intertank Plug Pulls completed Friday, scaffolding removed, platform E and B retracted Friday night. Umbilical Cover Plate removal ready to work. Retract D platform after plates are removed.”

All three orbiters now find themselves in busy flows, with Atlantis also undergoing the milestone of SSME (Space Shuttle Main Engine) installation, which has already started inside OPF-1.

L2 members : Documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, now over 4500 gbs in size

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