STS-122: Optimism on forward plan/smoking gun – SARJ update

by Chris Bergin

Thursday’s Program Requirements Control Board (PRCB) meeting has been presented with documentation that adds confidence to the initial findings of a “smoking gun” during testing of ET-125’s removed external LH2 Feed-through connector.

At the same time, plans are being put into place to use a special grease gun on the problematic starboard SARJ (Solar Alpha Rotary Joint) on the International Space Station (ISS).

**The most comprehensive collection of Shuttle, Ares, Orion and ISS related presentations and mission documentation, plus expansive daily processing documentation and updates are available to download on L2 **

STS-122 L2 Special NOW LIVE. **Click here for sample of L2 menu and content**

**STS-122 Special: 29 Flight Readiness Review (FRR) Presentations, Baselines and Mission Overviews. **Click here for FRR overview articles: Article 1Article 2** Payload Presentations and vast amounts of live, uploaded images and presentations, movies (several) – already 2400 megabytes strong**

**COMPLETE Section – over 1100mbs of presentations – on ECO/Feedthrough Connector issues and troubleshooting, graphical and data based – expansive.**

**LIVE updates on Atlantis STS-122 Troubleshooting Latest**

**LIVE updates on Discovery STS-124 Processing**

 **LIVE news updates on Endeavour STS-123 Processing**

STS-122 ECO related news content: *Scrub 1* – *MMT Debate* – *Scrub 2* – *Hale Memo* – *Forward Plan* – *Culprit Found* – *Tanking Test* – *Repair Options* – *MAF Plan**PRCB Debate* – *Plan Approved* – *Repair Schedule* – *Launch Date* – *New Issue* – *Hale Rallying Call* – *PRCB Launch Dates* – *New Connector Installed* – *Positive Test Results* – *Manifest Impacts*

STS-122 Troubleshooting Latest:

More test runs on the connector have been conducted at the Marshall Space Flight Center (MSFC), as STS-122 continues to return back into a launch posture for February 7.

Test runs on the removed connector continue to mirror circuit anomalies observed during the two scrubbed launch attempts – and the subsequent tanking test – adding confidence that the external connector is at fault.

‘Think we’ve found smoking gun on external feed thru connector. Testing of connector exhibited same characteristics seen during the countdown. Data analysis will be done to pinpoint location of break. Working on flight rationale and root cause,’ noted engineering information.

‘New connector installed on STS-122 vehicle. Preliminary leak checks are complete; working on closeout and refoaming. Cold temperatures at KSC have slowed down work but should not impact 2/7 launch date.’

Such is the expanse of data being gathered on pinpointing the root cause, testing may continue past STS-122’s launch, though shuttle management are understandably buoyant that the Marshall testing has – once again – proved their expects right, as they beginning building flight rationale for proceeding with the next stage of the forward plan towards launch.

‘During the LH2 test, ECO #4 failed in a repeat fashion, and ECO #2 showed a repeat ‘noisy’ condition, similar to the previous launch count down signatures.

‘While the data from the tests is still in review, reports are that all circuit anomalies experienced during our testing were representative of anomalies seeing during the STS-122 scrubs and tanking test.

‘That was a great day, and we in fact have the problem hardware in hand. In other words, most believe these failures represent the ‘smoking gun’ that points to the external portion of the connector as the failed hardware. These test results will provide much of the flight rationale for the feedthru connector R&R work.’

The low temperatures at KSC did delay the start of closeout of the work site on ET-125, following the weekend installation of the replacement connector hardware. However, the cure time schedule has some in-built flexibility, thus February 7 remains the viable launch date.

‘Due to low temperatures on 1st shift yesterday primer applications were delayed again,’ noted processing information on Wednesday. ‘Modifications to the enclosure around the feedthru plate were put in place yesterday to enhance the ability to maintain adequate temperatures to enable TPS applications and curing through the night, subsequent temperatures and humidity have been maintained successfully.

‘Conathane application was completed and in cure at 1645L. PDL foam pours began late on 3rd shift this morning (Wednesday) and foam cure is in work. ECO sensor wiring used during the tanking test is being removed and will continue through 2nd shift Wednesday.’

Though not believed to be a concern, tests are continuing on the observation of cracking of the glass seal, spotted on ET-125’s connector. Testing – which included an old X-33 connector – showed there is no concern on the possibility LH2 could leak through the cracks – which was the main safety issue, though engineers are continuing to finalize their data.

‘Glass cracks on connector seal have no affect on failure mechanism based on analysis. Engineering qual program is being established for those with cracks (STS-122, -123) and working on longer program to qual cracks generically. Preliminary test showed no leaks and program will test for crack growth.’

SARJ Latest:

With the ‘headache’ of the STS-122 ECO system issues soon to become a thing of the past, NASA managers are looking to find a solution to the starboard SARJ on the ISS – which is out of service, following findings that 1505 Nitride material is being ground away from the race ring.

‘Although STS-122 has slipped to early February, the Space Shuttle Program has confidence that the ET feed through connector modification in work will not only resolve the problems with this tank, but may well be the solution to the recurring problems with the ECO system,’ noted manager Paul Hill. ‘If so, it is well worth the wait to get this headache out of the way of all other Shuttle flights.

‘ISS has challenges of its own with the starboard SARJ and one of the starboard beta gimbals, each of which promises more EVA time for repairs necessary to restore full capability and support the remaining modules, experiment racks and a six person crew.’

Four options were discussed this week on a forward plan for a resolution for the SARJ, though a root cause is still uncertain. The solution won’t be implemented into Atlantis’ mission, though managers are looking to send up some of the required tools in advance – including a grease gun.

‘ISS Program requested additional items on STS-122 for a crack repair technique using the caulk gun filled with grease cartridges to lubricate to the SARJ ring,’ noted Stand-up report information. ‘This will be added to the manifest of STS-122.’

This points towards a possible acceptance of ‘option 4,’ which would involve EVAs to clean, lubricate and then run the SARJ. Other work will be involved in what will ultimately be an expansive forward plan.

‘Regarding the latest on SARJ, the SARJ Team recommended and obtained approval to plan on a NET ULF-2 Outboard Ops Mode R&R,’ noted an 8th Floor report.

‘This decision was based on a performance analysis, the lack of an identified root cause, and the ability to perform limited directed position and autotrack to get us past any pinch points for mission and stage activities. There remains forward work to determine if we 1) run the SARJ as-is, 2) clean and run, 3) lubricate and run, or 4) clean, lube and run.

‘The SSPCB also approved the recommendation to remove the TBAs manifested for 1J/A. These will remain on the ground in the event our root cause analysis determines that adjustments/modifications are required.’

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In addition to the work that could be incorporated into future shuttle missions, ISS managers are also looking at potential work that can be added into stage work on the ISS.

‘Expedition 18 asked to assess the impact of adding SARJ EVA’s to the increment. Initial assessment is that if the additional training starts in the Jan/Feb trip the crew loading will spike up to yellow,’ noted an ISS memo.

‘If the training starts in April the crew loading will spike just below red. The Backup crew would be Yellow. The assessment was made with the assumption that there would be no additional time in the US and that the US training requirements would be assessed.’

Regardless of the issues with the delay to STS-122, and the continuing SARJ evaluations, managers remain buoyant on the forward plans, as they prepare for six missions and a major increase to the size and operation of the orbital outpost.

‘On the brighter side, one of the ISS team’s leading problems each week is to continue bringing forward more tasks from later in the year for this crew to do since they keep plowing through the work faster than we can give it to them,’ added Paul Hill.

‘The fact is, hurdles or not, ISS is humming along beautifully with ESA soon to be an active partner in real time and JAXA a month behind them.

‘Likewise, look back on the ISS assembly made possible by an amazing string of Shuttle flights from Fall 2006 through STS-120. We are set to end the year with hardware onboard ISS to support six crew members and a repaired Hubble Space Telescope.’

L2 members: All documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, updated live.

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