Minutes for May 8, 2001 EVA AIT

To: Distribution

From: XA/Nancy J. Patrick

Subject: Minutes for May 8, 2001 EVA AIT

The EVA AIT met at the Johnson Space Center on May 8, 2001. Boeing/David Read and XA/Nancy Patrick co-chaired the meeting. Representatives from CB/Flight Crew Operations, XA/EVA Project Office, NC/Flight Systems Safety and Mission Assurance, DX32/EVA Systems/Mission Operations, OZ/ISS Payloads Office, and Boeing-Houston (EVA and Safety) were present. Representatives from the 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/Lou Ramon

PNCR-ISS-067: Stage 8A EVA Translation Path Protrusion Non-Compliance’s

MBS-01-2001: MBS MAS EVA Bolt Head Dimension

Decision: The EVA AIT approved this PIDS exception

NC 50022917: MBS EVA handrail length

Decision: The EVA AIT approved this PIDS exception

NCR-PG1-062: Commercial and Purchased Parts

4/24 status: The EVA AIT requested a revision to this NCR to provide specific information on what hardware is included in the NCR. Additionally, the EVA AIT requested that the NCR include statements that the hardware will be swatch tested, and that Boeing will address anything that fails swatch testing. B-Hou/Joe Thomas agreed to coordinate the change and provide a revision to Ms. Patrick for approval. The NCR will be approved out of board once it contains the information requested.

5/8 status: The NCR has not yet been revised. Mr. Thomas will address it as time permits.

NCR-PG1-056: Trailing Umbilical System (TUS) Interface Umbilical Assembly (IUA) Corners and Edges

4/24 status: EVA AIT withheld approval of this NCR pending MOD approval. MOD reported after the EVA AIT that the flight unit should be swatch tested, and the NCR indicates that the qual unit was swatch tested. MOD will coordinate with SVITO and determine whether the flight unit is scheduled for a swatch test.

5/8 status: No report on swatch testing or revising the NCR to reflect the swatch testing. The EVA AIT also requested that specific information should be included in the NCR to indicate which hardware fails to meet the sharp edge design requirement. Mr. Thomas agreed to address the open work and re-submit the NCR.

AI-556: Evaluate the 7A and 7A.1 flight EVA tasks against the allowable temperature range for EMU extended contact (-145°F to +240°F). Report any tasks that require extended contact that exceed this range, based on the EC thermal analysis provided. (DX32/Bob Adams)

This action remains open and will be addressed again on May 29. Mr. Adams did not attend and did not pass along any information regarding the status.

AI-578: Provide inputs on generic carriers and interfaces (i.e. SLP, FRAM, LMC, ESP) for items that need flight specific/cargo specific evaluation when the flight/cargo configuration is defined. These items have been raised in NBL and 1-g evaluations. (CA/Fernando Ramos, PG3/Tom Hagale, PG3/Steve Burks, XA/Tara Jochim, B-Hou/Matt Mickle)

This action remains open and will be addressed again on June 19. Mr. Ramos and Ms. Jochim developed some information for FRAM. Ms. Jochim will consolidate their list. Mr. Hagale reported after the EVA AIT that he has not made significant progress but agreed to emphasize the action more in the coming weeks.

AI-581: Determine where the requirement arose for use of PRDs to mate truss segments in a contingency. Check with NASA and B-HB SRP representatives. Determine how “hard” the requirement is and whether it is based on some EVA input that the task is feasible (PG1/Larry Price) (Report status of presentation to SRP proposing a different workaround)

This action remains open and will be addressed again on May 29. Mr. Price reported that the B-HB counter-proposal to the PRD operation (release the cargo element by pulling pins on the capture bar) was determined to be infeasible by both PG1 EV&CS and Mechanisms. The pins are not accessible to the EVA crewmember. Both groups are planning to report this to the ITCE IRB later in the week. At that presentation, EV&CS and other disciplines will request the resources necessary to develop the PRD option if the ITCE IRB decides to pursue that option instead. Mr. Price will report the results of the IRB discussion and the plan for remaining work.

AI-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. (B-Hou/Curt Carlton)

This action remains open and will be addressed again on May 29. B-Hou/Dave Moore (formerly SVITO) reported that the P6 radiators were swatch-tested on this face prior to P6 launch and no sharp edges were found. Mr. Boller reported that SVITO/Rob Johnson plans to complete swatch testing of the P4 radiator by the end of the month.

AI-595: Determine the recommended torque and torque tolerance required for MTS strut bolts (ES/John Zipay)

This action remains open and will be addressed again on May 29. Mr. Zipay did not attend and provided no status.

AI-597: Develop list of worksites that use the TM to evaluate whether there is an interference concern similar to the MTS strut bolts (PG1/Larry Price, Jon Bonuan) (Report plan/status of fit check for S1/P1 radiator ORU bolts that have shown interference by analysis)

This action remains open and will be addressed again on July 24. Mr. Bonuan reported that the hardware wouldn’t be in the proper configuration for a fit check until late July. Mr. Bonuan and Mr. Price reported that there are no special provisions or plans for this fit check, and Boeing is still not fully funded to support fit checks for these elements. DX32/Chris Looper agreed to coordinate with SVITO to schedule this fit check as soon as the hardware configuration allows rather than wait to schedule it when it’s convenient to do several fit checks. Since the fit for this area is questionable, the EVA AIT wanted to conduct the fit check as soon as possible.

AI-598: Determine the impacts of moving the S0 keel pin PIP pin tether attach point, and identify any schedule milestones that may drive us to making a decision by a certain date (PG1/Larry Price, Jon Bonuan)

This action remains open and will be addressed again on May 29. Mr. Bonuan reported that prior to addressing this question with the IRB, B-HB wanted to know whether EVA really felt the change was necessary. Due to budget and schedule concerns, EV&CS did not want to request the change unless EVA felt it was important. The EVA AIT reported that EVA felt that this issue needs to be addressed somehow, and wanted to know the cost and impact of the change requested before deciding whether this recommendation should be pursued. Another option is available (use of wire ties) that EVA can fall back on, but it doesn’t eliminate the risk as well as the requested option, and involves more EVA time. Mr. Bonuan reported that the physical change to the hardware is simple — screwing the tether attach point into another hole — but that the drawing changes make it difficult. EVA agreed that we can live without drawing changes and can help streamline the paperwork requirements.

AI-600: Coordinate EMU extended contact discussion with the Flight director office to review existing limits and planned documentation to determine if the data available satisfies operations requirements (DX32/Bob Adams)

This action remains open and will be addressed again on May 29. This action has been put on hold pending the resolution of the latest EMU extended contact temperature issue.

AI-602: Present MT RSU R&R inadvertent contact and proposed MT tether to OM/Skip Hatfield and ES/John Zipay to determine ISSPO position on RSU R&R operations (whether MT has to be/should be unlatched and whether tether is required for RSU R&R) (PG1/Nick Gaspar Larry Price)

This action remains open and will be addressed again on May 29. Mr. Gaspar is no longer working station and Mr. Price had not picked it up.

AI-603: Investigate whether MT has to be unlatched to provide EVA access to RSU or LDU for R&R (DX32/Michelle Hollinger, Bob Adams)

This action was CLOSED. Ms. Hollinger reported that in her investigations, there is no indication that the MT must be unlatched during RSU remove and replace. There is apparently some question as to whether certain failures of the RSU can prevent the MT from latching, but there are possible workarounds to these failures that are still being evaluated (its possible that the LDUs can override the RSU failure).

AI-604: Review the splayed Dzus fastener/MMOD shield contingency procedure with ISS Struc and Mech to confirm procedure is allowed. (DX32/Kerri Knotts) (ES concurrence reported prior to EVA AIT)

This action was CLOSED. Ms. Knotts reported prior to the EVA AIT that Boeing/Bob Foster (for ES/John Zipay) concurred with the splayed Dzus fastener workaround.

2. EVA ICD PIRN 79 (Torque Wrench) Resolution XA/Greg LeStourgeon, B-CP, B-HB

There was no presentation material for this topic. Mr. LeStourgeon reported that EC5 is working toward a June 15 date for updating the torque wrench CARD and submitting a revision to the torque wrench PIRN. This is an assigned EHB action item/CCBD through sustaining engineering. EC5 is attempting to certify the torque wrench to ±10% for torques above 40ft-lbs with an operations constraint to keep the torque wrench in its protective cover until just prior to use. They are still looking at whether the cover will keep the wrench warm enough for all ISS thermal environments. Ms. Patrick requested that they also try to document how long the torque wrench can be out of the cover and still provide ±10% accuracy, since several of the operations involve using the wrench on several bolts, possibly at different worksites. Mr. LeStourgeon agreed to look into this.

B-Hou/Dave Read reported that Canoga Park could accept this torque wrench accuracy. The RTAS contingency bolts require ±10% at 48ft-lbs, so the torque wrench can provide an acceptable torque for their bolts.

3. S3/P3 ULCAS/UMA Deployment Interference Status PG1/Roger Larsen

Mr. Larsen reviewed the bidding on the issue (UMA interference with clevis during ULCAS deploy) and reported that Huntington Beach has not yet decided on their recommendation for resolution. In addition to the interference issue, they have identified another issue with the main hinges on the deployment mechanism. In some thermal environments, shifting of the Clevis Bracket relative to the main hinges may lead to binding. They have identified 3 options for hardware re-design to address the issues and are preparing to take those forward to Huntington Beach management for a recommendation, possibly by the end of the month. They are still developing the details and impacts of the options at this time.

Option 1 is to redesign the yoke with a ball joint instead of the clevis fitting. This eliminates the clevis and therefore the clevis interference with the UMA. The ball joint fitting is attached on the longeron with 4 captive EVA bolts. A soft dock feature is planned but not yet incorporated in the design. EVA AIT members were concerned that thermal effects may make it difficult to line up the four bolts required for attachment. Mr. Larsen indicated that this option resolves the binding concern, but no one present understood why changing the type of attachment at the yoke end would alleviate the binding concern at the hinges. Mr. Larsen agreed to investigate this further. Option 1 involves 12 new drawings and 4 drawing changes, in addition to modifying the longeron and the yoke. Cost and schedule impacts are TBD.

Option 2 provides an EVA removable clevis. EVA would remove the clevis prior to ULCAS deploy, then re-install it once the UMA clears the longeron, then install the yoke into the clevis. The clevis is installed with 4 EVA bolts. Mr. Larsen indicated that this option also resolves the binding concern, however EVA AIT members raised the same questions as with option 1. This option requires modifying the longeron and the clevis fittings, however the number of drawing changes and the cost and schedule impacts are still under investigation.

Option 3 changes the clevis to a hinged clevis. This allows the clevis to rotate out of the way during ULCAS deploy. The charts did not indicate that this option resolves the binding concern, however EVA AIT members did not understand why the other options would resolve the binding concern but option 3 does not. This option requires modifying the longeron and the clevis fittings, however the number of drawing changes and the cost and schedule impacts are still under investigation.

Mr. Larsen then reported that in addition to the cost and schedule impacts for the various options identified, there are also concerns with whether changing the hardware affects the level of testing completed to date. The changes proposed are to hardware already designed, built and in final acceptance testing. In addition, changes to S3 and P3 probably require changes to the S3/P3 NBL mockups.

Significant discussion not included in the presentation material:

Mr. Larsen explained the binding concern in a little more detail. The binding concern is based on conclusions from analysis for thermal extremes. It is, however, based on measurements from the real flight hardware. It is possible that Huntington Beach will conclude this is not a concern by refining the analysis parameters.

Mr. Larsen agreed to update the issue status at the May 29 EVA AIT.

Decision: EVA prefers option 3. With this option, there is no loose hardware during deploy, and it allows for the easiest alignment of the interfaces. NBL evaluations are required for all of the options, since the interfaces are changing significantly from what was previously tested. In addition, EVA recommends HTV testing for option 1 if the bolts require fine alignment.

Action 611: Explain why changing the ULCAS from a clevis fitting to a ball joint (option 1 for UMA interference during ULCAS deploy), or making the clevis fitting EVA removable (option 2), eliminates the concern for binding at the ULCAS hinges, but providing a hinged clevis does not (option 3) does not. Report status of issue resolution with PG1 ITCE IRB

Actionee: PG1/Roger Larsen

Due Date: May 29, 2001

Method for Closure: Report to EVA AIT

4. SSAS Contingency Bolt Task Assessment Status PG1/Larry Price, CB

There was no presentation material for this topic. Mr. Price reported that Huntington Beach feels their worksite analysis is complete. They have provided WSA with acceptable worksites for all contingency bolts (some from S1/P1 when they are the incoming segment), and alternate, not fully compliant worksites on S0 for S1/P1 attachment for the bolts that B-HB planned to use the incoming segment. CB has not had a chance to look at the S0 worksites in the NBL yet, to confirm that we don’t have to rely on any worksites for the incoming segment. Mr. Looper noted that for several of the S1/P1 bolts, B-HB used the CETA cart, and it appeared that the CETA cart had been moved from its launch position. Mr. Looper asked whether the CETA cart has to be moved since that requires an additional task before the contingency bolts can be installed. Mr. Price agreed to look into it.

Mr. Price reported that the B-HB counter-proposal to the PRD operation (release the cargo element by pulling pins on the capture bar) was determined to be infeasible by both PG1 EV&CS and Mechanisms. The pins are not accessible to the EVA crewmember. Both groups are planning to report this to the ITCE IRB later in the week. At that presentation, EV&CS and other disciplines will request the resources necessary to develop the PRD option if the ITCE IRB decides to pursue that option instead. Mr. Price will report the results of the IRB discussion and the plan for remaining work on May 29.

Ms. Patrick reported that the SSAS contingency bolt torque data development has taken a back seat to efforts to gain funding for SSAS system level qualification/acceptance testing. This testing, if approved, will provide test data on the torque requirements. ES/George Gafka and Hung Nguyen were not available for the EVA AIT, and will provide test status and schedule information on May 29.

Action Item Closure: AI-581 remains open and will be addressed again on May 29.

Action 612: Determine whether CETA cart relocation from launch position is required for the S1/P1 SSAS contingency bolts that use the CETA cart. Determine whether this is required or just provides a better worksite position.

Actionee: PG1/Larry Price

Due Date: May 29, 2001

Method for Closure: Report to EVA AIT

5. Use of EVA "GCA" for berthing OC/Cal Brogdon

Mr. Brogdon presented a proposal for use of EVA crew to provide berthing cues for NASDA related berthing operations. Mr. Brogdon explained that NASA is responsible for operations on the 2J/A mission, but for follow on berthing operations related to HTV visits, NASDA is responsible for berthing operations.

Mr. Brogdon explained that the ISS program would like to reduce our reliance on SVS for later flights, since it costs ~$5 million per year to maintain. The 2J/A mission is the last currently planned use of SVS, and it now falls almost 2 years after the penultimate SVS operation. As a result, the program would like to eliminate SVS for 2/JA. The 2J/A berthing operations include berthing the Exposed Facility (EF) to the Pressurized Module (PM) and berthing the Exposed Section (ES) to the EF. Mr. Brogdon requested approval for EVA GCA for these two berthing operations to eliminate the SVS requirement after 13A.

Mr. Brogdon explained that prior to HTV arrival, the ES must be temporarily relocated to the Pressurized Section (PS) to open up a spot for the Exposed Pallet (EP). The EP is berthed to the EF, unloaded and then moved back to the HTV for return. The JEM-RMS cameras are used for nominal berthing cues. NASDA requested EVA back up to the JEM-RMS cameras that are normally used for these three berthing operations. NASA’s position is that NASDA should provide a backup berthing cue, independent of EVA, to support these three berthing operations when HTV arrives.

Significant discussion not included in the presentation material:

The EVA AIT evaluated the 2J/A operations first. The EVA AIT determined that these operations are acceptable for EVA GCA, however there are a few open items to address. Additional visual cues (markings) may be required for the EVA crewmembers to determine RMS positioning for these operations. Mr. Brogdon felt that this should not be a problem. The crew office EVA branch has evaluated the operations associated with these berthing tasks with the crew office Robotics branch and has determined that the robotic guidance and accuracy required are within the EVA capability and there is a reasonable chance of successful berthing. The EVA crew is already EVA during the planned EF to PM operation, however timeline changes may be required to accommodate EVA during ES to EF berthing (MOD EVA has performed a preliminary assessment and believes this is easily accommodated). EVA deferred to MOD for a final decision on whether the timeline changes required are acceptable. The overall timeline impact is approximately 30 minutes for incorporating the EVA GCA task, and there are adequate worksites to support it.

The on-going HTV berthing operations were then addressed. The EVA AIT disapproved use of EVA GCA for these operations. The biggest problem for these berthing operations is that there are no scheduled EVAs during HTV operations. Therefore several EVA sorties would have to be added every time the HTV arrives. Additionally, the EVA aids on the HTV (required for supporting re-berthing the EP to the HTV) are questionable since the HTV does not have nominal EVA requirements. The EVA positioning required is also near the HTV thrusters, which is a keep-out zone for EVA. The EVA AIT concurs with the program office recommendation to require an additional level of redundancy for HTV related berthing operations before EVA is allowed.

Decision: The EVA AIT concluded that EVA GCA is acceptable for 2J/A berthing operations (EF to PM and ES to EM), with some open work to adjust the mission timelines and evaluate specific visual cues available. The EVA AIT concluded that EVA GCA is not acceptable for HTV visit related berthing operations (ES to PS, EP to EF, and EP to HTV) because it requires additional EVA sorties and the EVA aids to support it are questionable.

6. Upcoming Events/Future Agenda Review XA/Nancy Patrick, All

Ms. Patrick reviewed the preliminary EVA AIT agenda for May 29. Presenters were requested to confirm agenda topics by COB Thursday, May 24.

The following topic was deferred — presenter did not attend

Report results of investigation into torque requirements (torque and allowable torque tolerance) for MTS strut bolts. EVA AIT members evaluate tools available that provide enough clearance and meet torque requirements. Determine if there are any impacts to upcoming S0 NBL evaluations.

Decision Required: Determination of whether EVA tools can meet tolerance requirements

Required Attendees: XA, Boeing-Houston, DX32, EC5, CB, ES, NC, OC, KSC/SSHIO, PGs, SLP, MSFC, ESA, NASDA, CSA

Action Item Closure: AI-595