STS-133: Discovery ready to rollover next week – EVA running order swapped

by Chris Bergin

Discovery had been placed on the Orbiter Transporter System (OTS) in preparation for her rollover next Wednesday. The veteran orbiter remains on track for her November 1 mission to the International Space Station (ISS), as managers refine the STS-133 mission content, including the swapping of the running order of the two spacewalks (EVAs).

STS-133 Processing Latest:

Despite the late request to re-open Discovery’s Payload Bay Doors (PLBDs) to install a Tool Stowage Assembly (TSA) – containing 30,000 mission patches – on to the Orbiter Docking System (ODS) structure, Discovery completed her Orbiter Processing Facility (OPF) processing requirements in good time.

“OV-103 (STS-133) Over the weekend completed installation of the TSA and got the PLBDs closed for rollover. Completed weight and C.G (Center Of Gravity). activities. Orbiter is now on the OTS with the gear retracted; finalizing preps for rollover. Still scheduled to roll Wednesday, September 8 to VAB (Vehicle Assembly Building),” noted KSC Ground Operations (L2).

“STS-133 ORMR (Orbiter Rollover/Rollout Mate Review) was held,” added Flight Operations and Integration on the latest Shuttle Standup/Integration review (L2). “It looks like we are on track to get Discovery rolled over next week. For STS-133, the payload walkdown is next week, Thursday and Friday.”

Next week, engineers will begin removing the final platforms that have surrounded Discovery during what is her final flight processing flow, as she sits patiently on the OTS over the long weekend ahead of the short trip to the VAB.

“OV-103 (OPF Bay 3): S0004 Orbiter/ET Mate is scheduled for next Wednesday,” added the NASA Test Director (NTD) processing update (L2). “Weekend work: None planned.”

The awaiting External Tank (ET-137), mated to the twin Solid Rocket Boosters (SRBs) inside High Bay 3 (HB-3), has had its X-ray inspections completed, after they were called for when a flight washer was found inside ET-138’s LOX/LO2 Feedline during routine inspections.

The scans are currently under review, although it is understood no FOD (Foreign Object Debris) has been found inside the tank.

“In VAB on ET-137, on LOX feedline BSTRA inspections, have completed all X-rays. They are in Engineering Review at this time,” added Ground Operations. “Continuing with final preps for orbiter mate on that tank. It will be ready to support next week.”

Final pre-orbiter mate work on the tank and boosters has included some minor repairs to ET-137’s Thermal Protection System (TPS) foam, while engineers work on bringing one of the VAB cranes back into service for the orbiter mate operations.

“SRB BI-144 / RSRM 112 / ET-137 (VAB HB-3): Orbiter Mate preps; Cover plate removal complete. Mylar film installation is in work,” added the NTD report. “PR (Problem Report): Foam Damage: Red dye, sanded, measured and blended on LH2 barrel are complete less closure.

“ET-137: Crane still down. High crew manually removed scaffolding and 30′ PIC board. L/R GEI/Igniter Heater Snap Shot is complete. Antenna Cover closeout; RTV-133 found void. Void repair is in cure.”

STS-133 Specific Articles:

STS-133 EVA Change:

Two EVAs were added to Discovery’s mission during the baselining process, with managers changing the mission duration from 8+1+2 days to 11+1+2 days to accommodate the spacewalk tasks during the docked phase of STS-133.

The first EVA will take place on FD-5 (Flight Day 5). As baselined EVA-1 would begin with EV1 retrieving the LWAPA (Light Weight Adaptor Plate Assembly) from the ISS and installing the LWAPA into Discovery’s Payload Bay, before installing the CLPA 1 onto the SPDM (Special Purpose Dexterous Manipulator).

Following this activity, EV1 would then remove EP1 from the SPDM before installing a cover over the SPDM CLPA 2, before moving to help EV2 with the the S1 FHRC P-clamps.

For EV2, EVA-1 would begin with the removal of Multi-Layer Insulation (MLI) blankets from ELC-4 ExPCA. This would be followed by part I of work on the S1 FHRC P-clamps. After that, EV2 would move down to Discovery’s Payload Bay to assist EV1 with LWAPA installation. Then, EV2 would then move on to perform work on the P3 CETA cart light before working on a bootie on the P1 PBVM.

EV2 would then relocate the APFR retrieve/tool Stanchion before beginning part II of the S1 FHRC P-clamp operation.

FD-7 will see EV1 and EV2 go back outside the ISS for the second and final EVA of the mission. The EVA begins with the Removal and Replacement of the ‘Lab CP13 Light’ followed by the installation of an S1 radiator grapple stow beam.

After that, EV1 would stow a TS stop and work on a S3 MT (Mobile Transporter) stop on the Starboard CETA Rail stub. Then, EV1 would work on a SSRMS Elbow CLA cover. EV1 would then move on to install a S0 Bay 3 Bootie/Grounding Connector. EV2 will work on the S3 CETA light. Both EVAs have a “message in a bottle” task.

However, the EVA-1 and EVA-2 running order has been swapped, following a meeting between ISS and Mission Operations managers – relating to the fallout from work relating to the successful task to remove and replace the Pump Module on the External Thermal Control System (ETCS) Loop A.

“Took some recommendations forward to the Space Station Program Control Board regarding the EVA for STS-133. Due to the Pump Module R&R, they have been evaluating the downstream impacts,” noted Mission Operations on the Standup report.

“The decision was made at the SSPCB to swap EVAs 1 and 2, and to do the first EVA prior to installing the PMM. This is for access for one of the tasks that was added.”

Mission Operations also added that they are still looking at impacts to STS-134 and looking at a potential fourth EVA for Endeavour’s mission next year.

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