Minutes for March 13, 2001 EVA AIT

To: Distribution

From: XA/Nancy J. Patrick

Subject: Minutes for March 13, 2001 EVA AIT

The EVA AIT met at the Johnson Space Center on March 13, 2001. Boeing/Larry Price, Curt Carlton and XA/Nancy Patrick co-chaired the meeting. Representatives from CB/Flight Crew Operations, XA/EVA Project Office, NT/Flight Systems Safety and Mission Assurance, DX32/EVA Systems/Mission Operations, ER/Robotic Systems, OM/ISS Mission Integration, OC/ISS Operations Office and Boeing-Houston (EVA and Safety) were present. Representatives from Boeing Development Centers supported by telecon. Copies of presentations can be obtained from XA/Bill Rollins, Building 1, room 661, (281) 483-1416.

1. Introduction/AI Review Boeing/Larry Price, Curt Carlton XA/Nancy Patrick

RMCT Clearance Envelope for Contingency Release — EVA tool clearance requirement waiver request

SSCN R-PCM-0473 (SSCN 5160A): Exception to EAS QDS M2, M7, M8, M9 and M10 EVA Gloved Hand Clearance

Decision: This Exception was approved out of board. An extension has been built for the P6 connectors that have a clearance concern for connecting the EAS, and there was some question at the EVA AIT as to whether the extension handles are required on the EAS connectors. The crew office investigated their flight hardware demo report and reported that the connector spacing on the EAS connectors is sufficient.

NCR-COL-ESA-0002/A: Safety NC, Sharp Edges (Columbus Module)

Decision: This NCR was approved. The hardware that does not meet design requirements will be swatch-tested and any issues will be addressed.

AI-543: This action remains open and will be addressed again on March 27. Ms. Patrick will work with Mr. Adams and Mr. Bue off-line to address it. Until the EMU certification testing and analysis are complete, we cannot completely determine how the operational reporting should be conducted.

AI-556: This action remains open and will be addressed again on March 27. The thermal analyses were delivered on March 6 and will be reviewed prior to the EVA AIT on March 27.

AI-573: This action remains open and will be addressed again on March 27. Mr. Pankratz reported that after discussion with the IRB chair, he was directed to schedule a separate meeting with the B-HB Chief Engineer. Ms. Patrick requested that Mr. Pankratz make every attempt to schedule that meeting prior to the March 27 EVA AIT and report results immediately to Ms. Patrick.

AI-574: This action was CLOSED. Mr. Looper reported that the general topic of lack of communication with the EVA crew while in the truss has been addressed previously at the JOP, and the TRRJ and pump module tasks fall within the guidelines of the JOP decision. See minutes below for additional information.

AI-580: This action remains open and will be addressed again on March 27. PG1/Steve Corday reported that in OP-01, the ETVCG (includes camera, pan-tilt unit and 6B box) is launched as a single unit. The luminaire is attached IVA and the integrated ETVCG and luminaire are taken EVA and attached to the stanchion and installed on the camera port. Mr. Corday agreed to review this plan with the B-HB C&T lead because he wasn’t aware of any launch packaging concerns.

AI-582: This action remains open and will be addressed again on March 27. Mr. Leggett reported that they were looking at what it would take to provide the information requested but had no formal position yet.

AI-583: This action was CLOSED. The fit check matrices were baselined and updated. See minutes below for additional information.

2. EETCS Radiator Accumulator PG2/Scott Boller

"Cross-Wiring" Issue

Mr. Boller reviewed the current radiator configuration and the fact that the operational implications of the Loop A accumulators being wired to the Loop B PFCS and vice versa. Should the system experience a leak, the FDIR response is to shut down the PFCS to keep the entire loop from leaking its ammonia. With the current configuration, a leak would result in the wrong PFCS being shut down, effectively shutting down the good loop and continuing to feed the leak on the bad loop. They are currently managing the problem with a modification to the FDIR firmware and PVCA Caution and Warning so that the wrong loop won’t shut down, and a modification to the telemetry display so the crew will be able to see which loop is really experiencing a problem.

The problem with the existing configuration and procedures are that the FDIR modification requires that only 2 of the 4 sensors normally used to detect a leak be used. Without the additional 2 sensors, small leaks or temperature changes through the normal range that result in pressure changes, that don’t really indicate a system problem could result in the PFCS shutting down. This requires full-time support from the MER to overcome an incorrect PFCS shutdown. The program has proposed a permanent jumper to return the system to full functionality with essentially the nominal wiring configuration.

Significant discussion not included in the presentation material:

The EVA AIT determined that while the worksite and connectors required for the fix were not part of 4A nominal operations, the access to these connectors has been tested in NBL testing. Additionally, this particular task has been added to the Canoga Park Neutral Buoyancy test coming up next month. The EVA AIT decided to reserve judgment on the task feasibility until that test is complete. Mr. Boller also agreed to look into whether a software update could fix this problem and therefore delete the requirement for the EVA task. Mr. Boller also agreed to determine whether there is an existing Chit in place with the procedures for the control center to execute should a PFCS shut down occur. The EVA AIT will address the topic again on April 10, after some information is available from the NBL test.

Action 584: Provide additional information on the software patch to fix the radiator accumulator cross-wiring issue — include impacts of updating the software during a planned software load.

Actionee: PG2/Scott Boller

Due Date: April 10, 2001

Method for Closure: Report to EVA AIT

Action 585: Confirm Chit has been submitted that documents specific response required for an ammonia leak in the current radiator cross-wired configuration for ISS real time operations

Actionee: PG2/Scott Boller

Due Date: April 10, 2001

Method for Closure: Report to EVA AIT

Mr. Kwan and CB/Leroy Chiao described the procedures required for ESP2 berthing. The program has moved toward deleting a dedicated berthing camera for the ESP2, and requested formal EVA AIT concurrence with the plan to use the EVA crew to assist in RMS mating. This had been addressed with EVA previously through a VCB topic discussion, with EVA concurrence (XA, MOD, CB), however there was no formal documentation of the concurrence.

Mr. Kwan explained that the EVA crew is required to remove the ESP2 from the payload bay and also to attach the ESP2 to the airlock. Because the EVA crew is already present, there is no additional EVA burden to provide input to the RMS operator during mating. Mr. Chaio reported that the crew office reviewed this particular operation in detail and found it acceptable and within crew and RMS capabilities. Mr. Chiao reported that the RMS operators uses RMS digitals to drive the ESP2 to the predicted position and the EVA crew then provides feedback on whether the RMS is in the proper position, and if not, how to correct. The RMS operator then continues on digitals until in the mating position. The crew office confirmed that there are sufficient visual crews to determine whether the ESP2 is in position.

Mr. Zimmer then briefly reported on the plans for use of EVA crew for berthing assistance. He provided a table of program baselined berthing activities with their primary and backup method for providing berthing cues. Mr. Zimmer reported that the only recent changes to the plan that affect EVA are the ESP2 berthing, P6 to P5 berthing, and S6 to S5 berthing operations. Mr. Zimmer is proposing that these be baselined as EVA assisted berthing. The only other changes to the plan involve going from SVS to a Berthing Camera System for elements later in the sequence. Mr. Zimmer explained that the SVS system will be expensive to maintain, which drove the program to resort to the BCS option. The only berthing operations with EVA as the primary berthing cue are the S6 and P6 berthing (change), ESP2 berthing (change), and P5 and S5 berthing operations (original plan).

Significant discussion not included in the presentation material:

Ms. Patrick asked about any contingencies that may affect the acceptability of using the EVA crew to provide visual feedback during mating. Mr. Kwan et al reported that there are contingencies during mating that would require re-berthing the ESP2 in the orbiter. The program’s desire is to provide power to the ESP2 within 6-7 hours from when it was last unpowered, to maintain ORU temperature limits. Ms. Patrick noted that there is some risk to the accomplishing that if the requirement for the EVA crew to assist in berthing adds to the timeline to the extent that the crew won’t have time to re-mate the power umbilicals should a problem occur. This is not a factor in deciding the berthing camera requirement at this time, since there is not enough information to determine whether the EVA visual assistance adds to the timeline at all, and if it does, that it makes the power connection impossible.

The EVA AIT emphasized that, as has been previously reported by the EVA team, using EVA for visual guidance for mating is acceptable for certain cases, however it cannot be used across the board and requires sufficient review of the individual case to be considered acceptable. Several factors play into whether the EVA crew can perform the task, and include whether sufficient visual cues are available and whether the EVA crew is available to assist at the time required. The EVA AIT emphasized that any plans for EVA assistance for berthing should be brought forward and reviewed before accepted by the ISS program.

Decision: The EVA AIT concurred with the program recommendation to use EVA crew for visual guidance for ESP2 rather than provide a berthing camera system for this case. Ms. Patrick requested that the crew office evaluate the remainder of the berthing cue plan and provide a recommendation on the other planned/requested EVA berthing operations.

Action 586: Evaluate EVA berthing operations outlined in Berthing Cue Plan (S6 and P6 berthing (change), ESP2 berthing (change), and P5 and S5 berthing operations (original plan)) and provide recommendation as to whether they are acceptable.

Actionee: CB/Leroy Chiao

Due Date: March 27, 2001

Method for Closure: Report to EVA AIT.

6A/9A/11A/12A/12A.1/13A FCM updates Tricia Mack, Chris Looper, John Haensly

No significant comments were received to any of the proposed changes to the FCMs. The changes were baselined.

There was no presentation material for this topic.

Mr. Looper reported that the Orbit Flight Techniques Panel (OFTP) had generically addressed requirements for continuous comm with the EVA crew previously. In principle, the JOP decided to allow for brief periods without comm, but stopped short of defining the specific conditions under which it would be allowed. The OFTP agreed to address each case individually to determine whether it is acceptable. Mr. Looper felt, and the crew office agreed, that the TRRJ and FHRC operations on S1/P1 probably fall within the OFTP recommendation since they involve short, intermittent support from the second EVA crewmember. Further, no specific comm analysis has been done yet to even determine that there won’t be comm with the EVA crew during this operation. Mr. Looper plans to first request the comm analysis and then review the specific scenario with the OFTP. The EVA AIT agreed to defer to the operations community to address the situation and no further EVA AIT actions are required at this time.

Action Item Closure: AI-574 was CLOSED

Mr. Fukushima presented a summary of the issue and the proposed workarounds.

During an NBL training evaluation in 1999, MOD and crew noted an interference between the struts and the tools during MTS strut installation. The recommended tool complement is the Torque Multiplier with the PGT (torque currently required is 1500 in-lbs, so the TM is required). MOD/Zane Ney reported the problem to B-HB/Eric Fukushima and they began investigating whether the interference was valid. B-HB analysis confirmed that on certain bolts, there is a definite interference. For other bolts, there is an interference in some tool orientations, but turning the tool to a specific orientation alleviates the interference. This was discussed during the S0 FCA and ES/John Zipay opened an issue with an action to come to the EVA AIT with the recommended EVA tool resolution. B-HB looked into other tools and tool orientations to drive the problem bolts. Mr. Fukushima then presented the PG1 recommendations to the EVA AIT.

The bolts that have a tool interference/concern with the struts and the proposed workaround are as follows:

• Fwd MTS Plates (4 bolts each): Bolt 4 has no PGT/TM orientation that is clear (PGT interferes, TM is marginal – 3 of 6 TM orientations show at least .05 inch clearance). Other bolts on these plates have at least some PGT/TM orientations that are clear, with at least minimal clearance (>.28inches) per the analysis. Proposed workaround is to either add the Right Angle Drive to the PGT/TM stack up (TM+RAD+PGT) for additional clearance or use the Torque Wrench instead. Analysis shows these tool combinations have enough clearance to work.

• Aft MTS Lab Plates (5 bolts each): Bolt 1 has no PGT/TM orientation that is clear (PGT interferes, TM has at least .2 inch clearance for all 6 possible TM orientations). All other bolts show at least .96 inch clearance for the TM with a pretty good range of possible PGT orientations. Proposal for bolt 1 is to add the RAD (TM+RAD+PGT) to provide additional clearance.

• Aft MTS S0 Plates (6 bolts each): PGT clearance assessment not yet complete, but estimate is that there will be some allowable range of PGT orientations that will provide some clearance for all bolts. If that doesn’t pan out, the recommendation is again to add the RAD for additional clearance for the PGT. For the TM, all 6 bolts show at least some clearance in all but 1 of 6 possible TM orientations. Bolts 2, 3, 4 and 5 look tight, but according to analysis show at least .31 inches of clearance for the TM.

There will be no way to do a fit check with the flight hardware for some (4 of 6) of the plates since they attach to the Lab, which happen to be the ones that have hard interferences identified. There is an SSCN (4566) in work that provides for a fit check with a lab simulator. Unless that happens, and it shows clearance for the PGT/TM stack up, and it adequately represents the flight hardware, we will have to assume using one of the alternate tool configurations.

Identified issues with the alternative tool proposals and the work required to resolve them:

• Current torque requirement for the bolts is 1500 inch-lbs. PG1 has not developed a torque tolerance for that value, and has no plans to do so until SSCN 1819 has been funded for this flight. Mr. Fukushima reported that the nominal torque required may go down, but that won’t be confirmed until 1819 data is delivered either (the EVA AIT noted that this is a nominal torque value which is part of the baseline contract, and should not be constrained to 1819 funding).

• The Torque Wrench can only achieve 1200 inch-lbs. Without the torque tolerance allowed, we don’t know if this is good enough. Further, the guaranteed Torque wrench accuracy is ±20%. For the highest possible torque wrench setting, that takes the guaranteed value down to 960 inch-lbs. (Ms. Patrick noted that the torque wrench can probably provide better accuracy at this high a torque, but the best it can achieve is ±10%, and would require a waiver even if 1080 inch-lbs is sufficient).

• Adding the RAD to the TM/PGT tolerance further reduces torque accuracy. No one present knew the extent of the increased inaccuracy, however it will probably be significant. This poses a problem on the high end of the torque value, since to guarantee 1500 inch-lbs, the setting required would have to take the inaccuracy into account and would possibly add to the high end of the torque allowed.

• An additional concern with the torque wrench is whether there are structure based WIFs available to accommodate using it. MOD and crew agreed to develop a plan to determine that answer.

• Finally, use of the torque wrench from structure based WIFs, results in a much higher EVA load at the structural interface than currently planned with the PGT. No one present knew whether this results in an EVA induced loads concern, especially at the LCA since the LCA is still the primary structural interface between S0 and the Lab at this point. Ms. Patrick requested that the Boeing-structures and loads team look at the new procedures and provide a recommendation.

Significant discussion not included in the presentation material:

The EVA AIT agreed to pose the questions raised with the experts in the community and address the topic at the next EVA AIT. Ms. Patrick summarized the discussion in an email and will contact representatives from Structures and Mechanisms to address the torque and loads questions. The EVA AIT also requested that Mr. Fukushima present the issue to the S0 launch package team for information and input. The EVA AIT also expressed concern that this issue surfaced first in an NBL training run rather than through EVA worksite analysis. PG1/Larry Price agreed to determine whether the Boeing WSA accounts for tool stack ups and clearances, and if not, how the requirements and operations are verified. The following actions were assigned:

Action 587: Present S0 MTS strut tool clearance issue to Launch Package Team for information and concurrence with actions/open work in progress. Request assistance in obtaining torque tolerance information to determine whether recommended workarounds (alternative tool complements) are adequate.

Actionee: PG1/Eric Fukushima

Due Date: March 27, 2001

Method for Closure: Report to EVA AIT

Action 588: Develop NBL evaluation plan for use of the torque wrench from structure based WIFs for the MTS struts that have a tool interference for installation. Evaluate PG1 proposed tool stack up for MTS strut installation and provide recommendation on whether they are sufficient.

Actionee: DX32/Chris Looper, Michelle Hollinger

Due Date: March 27, 2001

Method for Closure: Report to EVA AIT

Action 589: Investigate why standard WSA did not identify tool clearance issues for MTS strut installation. Determine whether other tasks are at risk for interference problems that have not yet been identified.

Actionee: PG1/Larry Price

Due Date: March 27, 2001

Method for Closure: Report to EVA AIT

Mr. Miller presented an issue with the PV Radiator design that requires operations workarounds for one of the on-orbit radiators, and possibly future element PV radiators. PVRs 1 and 2 are not qualified for on-orbit relocation because the A & B center attachment fitting bearings can stick at thermal extremes, and if stuck at in an extreme angle, it could prevent the center attachment rod from inserting through the fitting. PVR 2 was launched on P6 and PVR 1 will be launched on P4 (12A). PVRs 3 and 4 (EEATCS radiators launched on P6) were repaired prior to launch. Mr. Miller proposed an EVA task to use the proposed MT/CETA rail installation alignment tool to unstick and align the bearings should they be misaligned and should the requirement arise to relocate either PVR1 or PVR2 on-orbit. The task entails inserting the alignment tool in the center attachment fitting, imparting a torque-type force to align the bearings while the radiator is held by the SSRMS.

Significant discussion not included in the presentation material:

There are no planned relocations of PVRs 1 or 2. The only requirement to do so would be if one PVM loses a PVR and either P4 or P6 has a good radiator but is down for some other reason. The EVA task appears feasible, however no one present knew the force imparted on the radiator results in the SSRMS slipping. Additionally, no one present knew whether the radiator meets sharp edge requirements where the EVA crew would be required to perform this task. B-Hou/Curt Carlton agreed to look into these questions and report back to the EVA AIT. OC/Ron Torcivia plans to pursue fixing PVR 1 (P4 PVR) prior to 12A if at all possible.

Decision: The EVA AIT concluded that if there are no sharp edge concerns, and if the SSRMS can provide a steady platform, the proposed PVR center attachment fitting workaround is acceptable.

Action 590: Determine whether the PVR meets sharp edge requirements for the surfaces to which the crew is exposed for the PVR center attachment fitting workaround, and whether the SSRMS can hold the PVR in place without slipping for the workaround.

Actionee: B-Hou/Curt Carlton

Due Date: April 10, 2001

Method for Closure: Report to EVA AIT

Ms. Patrick reviewed the preliminary EVA AIT agenda for March 27, 2001. Presenters were requested to confirm agenda topics by COB Thursday, March 22.

DX32/Chris Looper reported that during a Rotary Joint Motor Controller (RJMC) 6B box installation at KSC, there was a problem installing some of the bolts. The proposed workaround (from PG1) should this problem occur on-orbit was to only attach the center bolt of the 6B box. Mr. Looper requested a recommendation as to whether this can be an acceptable configuration for all 6B boxes, since the preference is to drive the minimum number of bolts required. PG1/Larry Price agreed to look into it and provide a status in two weeks.

Action 591: Determine if the RJMC 6B box workaround proposed during KSC installation task (to use only center bolt) is acceptable for all 6B boxes for on-orbit operations

Actionee: PG1/Larry Price

Due Date: March 27, 2001

Method for Closure: Report to EVA AIT