Hubble And Shuttle:

The association between the Space Shuttle fleet and Hubble began at the point of the telescope’s departure from Earth, under the protection of Shuttle Discovery, as she lofted HST into orbit in her cargo bay on STS-31.

That early morning launch over 22 years ago always promised a new era of discovery, but it was the Shuttle fleet’s unmatched versatility that would prove to be the key for ensuring Hubble would fulfil its role. After all, Hubble – much to the shock of its team – was launched with a major fault.

The fault was only discovered after scientists first started to receive imagery from the telescope, revealing the main mirror had been ground incorrectly, effectively compromising Hubble’s eyesight.

Discovery’s younger sister came to the rescue of Hubble in 1993, as Endeavour launched on only her fifth mission to carry out a critical service mission, with the main goal of correcting the telescope’s impaired vision.

With STS-61′s five EVAs successfully installing a corrective optics package – along with new solar arrays – during the highly complex 11 day mission, Hubble was back to full health and started to provide the stunning images of the cosmos that have fascinated the entire human race ever since.

Discovery would return to Hubble in 1997, as STS-82′s mission upgraded the telescope’s scientific instruments, and increased its research capabilities. Discovery would visit her favourite telescope once again on the third servicing mission in 1999, replacing all six of Hubble’s gyroscopes – three of which had failed – along with replacing a Fine Guidance Sensor (FGS) and the telescope’s computer.

In what was Columbia’s penultimate mission prior to her tragic loss, STS-109 carried out the fourth servicing mission in 2002.

The five EVA mission installed the Advanced Camera for Surveys (ACS), new rigid Solar Arrays (SA3), a new Power Control Unit (PCU) and a new Cryocooler for the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). Columbia also provided Hubble with a farewell push, as the orbiter reboosted the telescope to a higher orbit.

Due to Columbia’s loss the following year, NASA managers were left with a dilemma. Hubble was next scheduled to be serviced in 2005, yet NASA’s own Return To Flight (RTF) rules insisted on the “safe haven” requirement, allowing for an orbiter, damaged during launch, to fly to the International Space Station (ISS) for its crew to await another shuttle to bring them home safe.

With this “safe haven” requirement impossible for a mission to Hubble, the final Shuttle servicing mission was cancelled. However, with a robotic mission deemed not to be viable, pressure grew both at the public and political level to review the cancellation.

In 2005, incoming NASA administrator Mike Griffin eventually approved SM-4 for Atlantis and STS-125, after the Space Shuttle Program (SSP) started to prove its new safety measures were working – such as the increasing mitigation of External Tank foam loss and advances in Thermal Protection System (TPS) inspection and repair techniques – during the opening salvo of post-RTF missions.

The best possible crew were assigned to Atlantis for the final rendezvous between the world-famous vehicles, led by commander Scott Altman, assisted by six crewmembers that included John Grunsfeld and Mike Massimino.

Endeavour would also receive a co-star role by standing by as the STS-400 rescue mission, seeing her sat on Pad 39B ready to launch at short notice in the event Atlantis’ launch – from Pad 39A – suffered a major issue during the ride uphill on what proved to be a delayed launch date, as Hubble itself worked through problems on orbit.

That contingency wasn’t required, as Atlantis and her crew conducted a flawless launch and rendezvous with Hubble in May, 2009 – no easy task even under nominal conditions, as the orbiters used up nearly half of their prop capability just to reach the “height” of the telescope’s orbit and can endure higher MMOD risks.

The 14 day mission involved five back-to-back EVAs, including its own challenges – highlighted by Massimino literally using brute force to pull off the STIS hand rail from the telescope (see L2 video) during EVA-4.

However, the mission achieved all of its primary goals, including the installation of two new instruments, namely the the Cosmic Origins Spectrograph (COS) and the Wide Field Camera 3 (WFC 3), leaving Hubble in a great condition to continue its role for many years to come.

One such example of the legacy Atlantis and STS-125 provided was seen via a NASA release on Wednesday, relating observations made by WFC 3 – an instrument that is much more capable than the WFPC2 (Wide Field and Planetary Camera 2) which it replaced.

Thanks to its additional imaging sensor that works in the near infra-red – something the older camera was not capable of – astronomers announced they have seen further back in time than ever before and have uncovered a previously unseen population of seven primitive galaxies that formed more than 13 billion years ago, when the universe was less than three percent of its present age.

These deepest images to date from Hubble yield the first statistically robust sample of galaxies that tells how abundant they were close to the era when galaxies first formed.

The results are from an ambitious Hubble survey of an intensively studied patch of sky known as the Ultra Deep Field (UDF). In the 2012 campaign, called UDF12, a team of astronomers led by Richard Ellis of the California Institute of Technology in Pasadena used Hubble’s Wide Field Camera 3 (WFC 3) to peer deeper into space in near-infrared light than any previous Hubble observation.

Without STS-125′s delivery of the WFC 3 to Hubble, the latest results would have been extremely difficult to obtain.

The observations were made during six weeks in August and September, and the first scientific results now are appearing in a series of scientific papers.

“Our study has taken the subject forward in two ways,” Ellis explained. “First, we have used Hubble to make longer exposures. The added depth is essential to reliably probe the early period of cosmic history. Second, we have used Hubble’s available color filters very effectively to more precisely measure galaxy distances.”

The team estimated the galaxy distances by studying their colors through a carefully chosen set of four filters at specific near-infrared wavelengths.

“We added one filter, and undertook much deeper exposures in some filters than in earlier work, in order to convincingly reject the possibility that some of our galaxies might be foreground objects,” said team member James Dunlop of the Institute for Astronomy at the University of Edinburgh in Scotland.

Astronomers have long debated whether hot stars in such early galaxies could have provided enough radiation to warm the cold hydrogen that formed soon after the big bang. This process, called “reionization,” is thought to have occurred 200 million to 1 billion years after the birth of the universe. This process made the universe transparent to light, allowing astronomers to look far back into time. The galaxies in the new study are seen in this early epoch.

“Our data confirm reionization was a gradual process, occurring over several hundred million years, with galaxies slowly building up their stars and chemical elements,” said Brant Robertson of the University of Arizona in Tucson. “There wasn’t a single dramatic moment when galaxies formed. It was a gradual process.”

So while Atlantis is now long retired since completing her STS-135 mission, and is preparing to go on display to the public in her new facility at KSC’s Visitor Center, she – and her crew – can be proud of the legacy one of her many missions is continuing to provide to the public they served.

(Article images via L2, L2 Historical, NASA and Ed Cheung)

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In all, the first half of 2009 proved an extremely challenging and rewarding time for NASA. Form January to June, NASA completed a complicated analysis of the Space Shuttle fleets Flow Control Valves, launched the Kepler Space Telescope to search for extra-solar Earth-like planets, conducted the STS-119 Shuttle mission, performed a dual-pad flow for STS-125 and STS-400 and the subsequent and highly successful STS-125 mission to upgrade the Hubble Space Telescope, and launched LRO/LCROSS.

In a recent interview with NASASpaceFlight.com, Space Shuttle Program Launch Integration Manager Mike Moses talked extensively about the incredible year the Shuttle processing teams had and their ability to accomplish everything they did in 2009.

“It was all about the teams and their ability to create triple and quadruple redundancies in schedules,” Moses said.

“On the surface, it didn’t appear that we had all that challenging of a year. But if you take it month by month you can really see the issues the teams worked through and the amazing jobs those teams did to get us into a launch posture six times this year.”

Flow Control Vales Investigation:

This ability to create multiple processing scenarios was first seen during the Flow Control Valve (FCV) investigation following the STS-126 flight of Endeavour in late-2008.

Click here for NASASpaceflight.com articles on the FCV issue since STS-126.

While 2009 began in earnest for NASA with the mating of Space Shuttle Discovery to her External Tank for the STS-119 mission to the International Space Station in February, the small crack and liberation from one of Endeavour’s (STS-126) Gaseous Hydrogen (GH2) FCVs kicked off an investigation into the integrity of the fleet’s FCVs, prompting NASA to delay Discovery’s mission.

As noted by the Safety Engineering & Integration document for the STS-126 In-Flight Anomaly (IFA) review, “During 2nd stage, there was an uncommanded drop in SSME (Space Shuttle Main Engine) #2 hydrogen outlet pressure. Data indicates FCV #2 opened without removal of close command. Valves #1 & 3 compensated.”

Furthermore, “During ascent and after the thrust bucket, the E2 (Engine #2) GH2 outlet pressure had a 200 psi step down without a corresponding ullage pressure signal conditioner command change,” noted the Orbiter and GFE (Government Flown Equipment) IFA review presentations for STS-126. “The delta outlet pressure for this FCV position was 260 psi during previous command changes before the thrust bucket.”

While the anomaly did not have an impact on ascent performance of STS-126, it did create a constraint to the launch of STS-119 because any failure of the GH2 FCVs is a 1R/2 condition: a condition that must be explained/corrected prior to the next Shuttle launch.

As such, NASA initially delayed the launch of STS-119 by one week, from February 12 to February 20 so engineers could complete an investigation and safety analysis on the FCVs. As the investigation continued and engineers determined that more time was required to adequately complete their investigation and analysis, NASA further delayed STS-119 to February 27, before eliminating a No Earlier Than target launch for STS-119 until all engineering departments arrived at a Flight Rationale acceptance plan.

This decision to postpone the launch of STS-119 until a resolution to the FCV issues could be obtained highlights NASA’s strict attention to safety for the crews of Space Shuttle missions – a theme that pervaded 2009.

Aided by eddy current investigation tactics, NASA engineers were able to create a screening processing for the Shuttle fleet’s FCVs, enabling NASA managers to have the best information possible on the condition of each GH2 FCV prior to and following flight.

Following the implementation of this eddy current inspection procedure, and subsequent testing of various sized FCV liberation pieces, technicians at the Kennedy Space Center replaced all three FCVs on Discovery with FCVs that were deemed “good” via eddy current inspections.

Furthermore, Discovery’s Main Propulsion System (MPS) plumbing was beefed up via the addition of a “doubler” around a 90-degree elbow joint located downstream of the FCVs to ensure that – in the event of the FCV liberation event – any liberated piece of FCV would not cause series damage to the MPS plumbing.

Through these final efforts and analyses, NASA set March 12 as the new No Earlier Than (NET) launch date for STS-119 – a launch date that was eventually advanced to March 11 thanks to the superb efforts of all the engineers and technicians involved in completing work and final analyses ahead of schedule.

NOAA-N Prime, Orbiting Carbon Observatory, & Kepler:

While the investigation into the FCVs took place, NASA proceeded with two satellite launches: the NASA NOAA-N Prime satellite on a Delta II rocket and the Orbiting Carbon Observatory (OCO) aboard a Taurus rocket, both from Vandenberg Air Force Base, CA.

The NOAA-N Prime satellite was successfully placed into orbit on February 4 while the OCO’s launch unfortunately ended in failure when the pyro bolts used to separate the rocket’s fairing failed to detonate.

As a result, the fairing remained attached to the Taurus rocket, creating an insufficient thrust to weight ratio for the rocket and its engines. The upper stage of the Taurus rocket, with the OCO and fairing still attached, was destroyed when it impacted the Southern Ocean north of the Antarctic ice shelf about 17-minutes after liftoff.

The failure of the OCO mission prompted NASA and its ULA (United Launch Alliance) partner to conduct a thorough investigation into the pyro bolts used on the veteran Delta II rocket’s payload fairing prior to the early March launch of NASA’s Kepler Space Telescope.

This investigation, called mainly because of the similar nature of the pyro bolts on the Taurus’ and Delta II’s payload fairings, revealed that all pyros on the Delta II’s fairing surround Kepler were acceptable for liftoff.

Nevertheless, the resultant investigation pushed back the launch of Kepler by one day. Liftoff occurred on time on March 6 at 10:39:57p.m. with the Delta II rocket placing the Kepler telescope into a Earth-trailing solar orbit.

Dedicated to the detection and study of extra-solar terrestrial planets that orbit their parent stars inside the habitable zone, the Kepler mission is the first in a proposed series of missions that will study the characteristics of Earth-like extra-solar planets.

Unlike previous observations conducted by orbital and ground-base telescopes, Kepler continuously observes approximately 100,000 stars at one time looking for the tell-tale “dimming” effect caused when a planetary body passes in front of its parent star – a detection method known in the scientific community as the transit method of detection.

The Kepler telescope began its official mission two months after its launch. The first results from the Kepler mission will be announced at an American Astronomical Society meeting on January 4, 2010.

STS-119 Launch Campaign:

With the launch of the STS-119 mission postponed until mid-March at the earliest, NASA – once the FCV issue was adequately resolved – began to assess the launch opportunities for Discovery in relation to the Soyuz crew rotation mission to the International Space Station (ISS) later that month.

Click here for NASASpaceflight.com articles covering STS-119

Since Shuttle and ISS Program Flight Rules prohibit the docking and undocking of any spacecraft to/from the ISS while a shuttle orbiter is docked, Discovery/STS-119 was faced with either a three day launch window (March 11 – 13) to ensure full mission duration, or the deletion of mission content and EVAs (spacewalks) for launch attempts from March 14 – 17.

In the end, mission planners and NASA decided that it was in the agency’s and the ISS Program’s best interest to launch STS-119 prior to the Soyuz crew rotation – even if launching in March meant the deletion of up to four Flight Days and three of the mission’s four EVAs to ensure that the S6 truss was delivered to the ISS and Discovery undocked prior to the launch of the Soyuz spacecraft.

This plan – the creation of multiple scenarios to ensure maximum performance from all partners during STS-119 – exemplifies the commitment of all departments in conducting the best mission possible.

Furthermore, due to the multiple plans put in place for contingency launches up to March 17, Shuttle Program managers and launch officials had a clear forward path to follow upon scrubbing the March 11 launch attempt due to a Gaseous Hydrogen leak from the Ground Umbilical Carrier Plate (GUCP) between the External Tank and Gaseous Hydrogen vent line on the launch pad.

In response to this leak, engineers determined that the best option for correcting and eliminating the issue would be to remove and replace (R&R) the GUCP Quick Disconnect seals – the suspect cause of the leak.

Undertaking this effort while launch personnel retargeted STS-119′s launch for March 15 proved to be yet another tremendous demonstration of the team’s abilities. Encountering some problems with alignment of the pivot assembly on GUCP, engineers found themselves eight hours down on the GUCP seal R&R timeline just two days prior to the retargeted launch date.

Nonetheless, engineers successfully completed repairs to the GUCP and the leak did not repeat itself during the launch campaign on March 15.

As a result of all the hard work from engineers around the country, STS-119 and the Space Shuttle Discovery was successfully launched on March 15 at 7:43p.m. in what Launch Director Mike Leinbach described as the “most visibly beautiful Shuttle launch.”

In all, STS-119 was successfully accomplished in 14 Flight Days and three EVAs – two days and one EVA shorter than originally planned. Despite some disturbed weather in the area – which prompted the Entry Flight Director in Mission Control to wave off Discovery’s first landing attempt on March 28 – the vehicle and her seven member crew successfully landed at the Kennedy Space Center on March 28 on their second deorbit and landing opportunity of the day.

STS-125/STS-400 Operations:

Three days after the successful landing of Discovery/STS-119, the flagship mission of the final shuttle flights was transported to Launch Complex 39-A. Atlantis and the STS-125 stack were rolled out to the sea-side launch pad approximately 40-days before the scheduled launch of the fifth and final Hubble Space Telescope servicing mission.

Click here for NASASpaceflight.com articles covering STS-125 - and STS-400 Launch On Need

Two weeks later, the Space Shuttle Endeavour and the STS-400 stack (the Launch On Need rescue flight for the STS-125 crew) was rolled out to Launch Complex 39B, marking the 19th and final time in Space Shuttle Program history that that both KSC launch pads were occupied at the same time.

In fact, Endeavour’s rollout to Pad-B came just days before the scheduled delivery of the STS-125 payload to Pad-A and one day before a KSC Open House for employees and their families. This provided an even rarer moment of both Rotating Service Structures being retracted from both Endeavour and Atlantis at the same time, giving KSC engineers and their families the opportunity to see both Atlantis and Endeavour on Pads-A and -B in all their glory.

Furthermore, the rollout of Endeavour to Pad-B and the delivery of the STS-125 payload to Pad-A represented the first step in the culmination of a near 3-year effort on behalf of various NASA agencies in what would prove to be the second the final launch campaign for the Hubble servicing mission.

However, while the sight of two shuttles on both pads and the spectacular flight of STS-125 might have been the visual coup de grace of the compilation of the Hubble mission, it is the behind-the-scenes work for thousands of engineers, technicians, and the astronauts that brings to light the true sense of pride and accomplishment felt by all during and after the Hubble flight.

In fact, work on HST-SM4 (Hubble Space Telescope Servicing Mission 4) began long before the cancellation of the mission by then NASA Administrator Sean O’Keefe following the loss of Columbia in February 2003.

In an interview with NASASpaceFlight.com, engineer Ed Rezac with the Goddard Space Flight Center in Greenbelt Maryland stated that HST-SM4 had been in the works for several years and that engineers even began looking at a non-Shuttle way to reach Hubble for servicing after the initial cancellation of the SM4.

“All along the program had been working on SM4 and when we got the news that we might not see another Shuttle flight because of Columbia, the program immediately started looking at other ways to get to the telescope to service it.”

But despite the long lead time in terms of the number of years SM4 had in the planning community, the fact that the mission would be the final servicing mission to Hubble drove engineers to replace and/or fix/repair as much as possible on the telescope to leave it in the best possible condition.

This plan included the addition of two late repairs/replacements – one of which caused NASA to delay the launch of STS-125 by seven months just weeks before the mission was supposed to launch in October 2008.

This delay was caused by the failure of the A-side of the Science Instrument Command and Data Handling Unit (SIC-DH) on September 27, 2008. Even though engineers were able to restore command function via the B-side of the SIC-DH, all redundancy for the system had been lost.

As such, the decision was made to delay the launch of STS-125 until a replacement SIC-DH unit could be ground tested and flight rated for installation to the Telescope – thereby restoring full redundancy to the system.

“There were a couple things that came up at the last minute,” said Ed Rezac. “The SIC-DH had to be replaced and the Advanced Camera for Surveys (ACS) went out in the midst of our planning and we were able to demonstrate a feasible plan to Headquarters for fixing both components.

“At the same time we carried over previous things from other servicing missions that we knew we wanted to accomplish on those missions but couldn’t. So we really made a good effort to leave Hubble in the best possible condition at the end of this mission.”

Furthermore, STS-125 and all the engineers and astronauts involved benefited from a two and half year training period – a training period significantly longer than standard ISS missions.

In fact, this translated to multiple runs of the various EVAs (Spacewalk) in the Neutral Buoyancy Lab (NBL) at the Johnson Space Center.

As Ed Rezac states, “We had two repairs on the ACS and STIS instruments that necessitated the removal of non-captive parts. So there was a lot of development that went into capturing these pieces and getting an astronaut into the tight confines of the aft shroud. These instruments were never designed to be serviced on orbit, so the NBL was an invaluable tool in helping us develop and refine our procedures.”

Nonetheless, the teams’ ability to create multiple scenarios for the different repairs, as well as the difficulties the astronauts could face once on orbit, allowed ground engineers to trouble-shoot – in real time – during the mission’s five back-to-back EVAs.

It was this type of dedication and forethought that permitted the STS-125 crew to work through a few issues on orbit during the servicing mission – one of which required Mike Massimino to physically break off a handrail on the Telescope in order to gain access to Hubble’s ACS instrument.

In all, STS-125 was a highly successful mission in which all of the mission’s EVA objectives were accomplished. Atlantis was launched from Pad 39-A at 14:01:56 EDT on May 11 and rendezvoused with the Telescope on May 13. The next five days were spent conducting the mission’s five EVAs.

The STS-125 crew released Hubble back into its orbit on May 19 and, after two days of weather wave offs, landed safely at Edwards Air Force Base, CA on May 24 at 11:39:05 EDT – capping a 12-day 21-hour 37-minute 9-second mission.

STS-125 was the first solo flight of Atlantis (meaning it was the first mission for Atlantis that did not involve docking with a Space Station) in 14-years since her STS-66 mission in November 1994. The mission was also Atlantis’ 30th voyage to space and first voyage to the Hubble Space Telescope – which had previously been serviced twice by Discovery and once each by Columbia and Endeavour.

In the end, the STS-125 campaign represented a tremendous effort for all involved. Atlantis was not only successfully processed for STS-125 in April and May but Endeavour was also processed at the same time for her role on STS-400.

In fact, STS-400 was processed out to the L-7 point (Launch minus seven days) at the time that Atlantis launched. This would have allowed NASA to launch Endeavour as early as seven days after the launch of STS-125 should Atlantis have incurred serious Thermal Protection System damage during ascent.

Still, Endeavour was kept on stand-by throughout STS-125 to further act as a quick rescue vehicle in the event of Micro-Meteoroid Orbiting Debris damage to Atlantis.

Once Atlantis safely landed in California, engineers at the Kennedy Space Center deconfigured Endeavour from her launch-ready condition. Endeavour and the STS-400 stack were then re-designated as the STS-127 stack and rolled around from Pad-B to Pad-A for final preparations for the mid-June target launch of STS-127 to the Space Station.

This launch campaign for STS-127 would mark the beginning of the second half of 2009 for NASA.

A second Year in Review article pertaining to the second-half of 2009 for NASA will be published in the coming days.

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In-Flight Anomalies from Previous Vehicle Flight (STS-125):

Perhaps the most prominent In-Flight Anomaly experienced by Atlantis during her flagship mission to the Hubble Space Telescope in May was the failure of the ASA-1 (Aerosurface Servo-amplifier Assembly channel One) system.

“Immediately before launch, all aerosurface servo-amplifier assembly (ASA) channel one positions went off scale low,” notes the Orbiter Project Office’s (OPO’s) presentation to the SSP FRR in mid-October.

As a result, the Remote Power Controllers in Atlantis were tripped approximately 1-second after SRB (Solid Rocket Booster) ignition – which caused the annunciation of the Caution and Warning alarm on Atlantis’ Flight Deck.

Given the redundancy in the system, Atlantis’ crew was told to bypass the ASA-1 system. Flight Controllers monitored the remaining three ASA channels throughout Atlantis’ mission – as the failure of two ASA channels would have meant an early termination of the flight.

After Atlantis’ landing at the Dryden Flight Research Center, limited troubleshooting was performed – troubleshooting that did not reveal any shorts in the ASA system.

After Atlantis was ferried back to the Kennedy Space Center, the ASA-1 was Removed and Replaced (R&Red), with Hi-pot testing of the Right Hand (RH) inboard elevon’s primary delta pressure transducer circuit indicating a “short to ground.”

All other ASA-1 circuits with “400 Hz excitation voltage were Hi-pot tested.” No further anomalies were detected.

However, troubleshooting did not end there. “Further isolation and inspection found discrepant wire harness chafing against an adjacent Hi-Lok fastener in the actuator cavity region,” notes the OPO presentation – available for download on L2.

These wire harnesses were removed for failure analysis, which revealed the cause of the ASA-1 failure to be an “exposed conductor within the wire harness shorting to the Hi-Lok fastener.”

Furthermore, the Test, Teardown, and Evaluation (TT&E) and failure analysis at the NASA Shuttle Logistics Depot (NSLD) of ASA-1 verified that the short was external to the LRU – which caused the failure of the ASA-1 excitation card,” notes the OPO presentation.

Following the replacement of this card, ASA-1 was subjected to an ATP (Acceptance Test Procedure) vibration test. No shorts were monitored during this testing.

Overall, Flight Rationale for the ASA system has been documented and accepted by the Space Shuttle Program (SSP) and the Space Operations Mission Directorate (SOMD), which both cleared the issue for STS-129.

Given that the damaged wire harnesses were identified and replaced, that ASA wire redundancies were assessed and deemed to be well within safety standards, and that extensive, hands-on investigations of the redundancy systems were carried out, the ASA system is not expected to be an issue for Atlantis and STS-129.

Nevertheless, during these hands-on inspections, “two areas of redundancy routing violations were identified and corrected, remaining Right and Left Hand inboard/outboard elevon actuator harnesses were inspected for damage, and overbraid damages were repaired,” notes the OPO presentation.

Additionally, harness routing locations in the RH and LH elevons were re-documented and further baseline wire inspections were performed in the wings, vertical stabilizer, main landing gear wheel wells, and struts to “increase confidence in overall system integrity.”

In all, 27 Problem Report “conditions” were detected and repaired on OV-104 (Atlantis) during these wiring inspections. As such, Atlantis is cleared for flight on STS-129.

In addition to the ASA-1 issue, turnaround flow engineers faced another issue with Atlantis – in the form of a “quick show mount knob” that was found to be wedged between pressure pane #5 and the console dashboard close-out panel.

Engineers and technicians tried several times (using several different methods) to remove the wedged knob.

“After a number of methods were utilized to remove the knob without inducing further damage to the pressure pane, the knob was successfully removed without further damage to the pressure pane by chilling the knob while employing mechanical motion and pressurizing the crew compartment (2-3 psig).”

This pressurization of the crew compartment was attempted after careful consideration and analysis on the possible effects of pressurizing the crew compartment at sea level.

Originally, it was thought that pressurizing the crew compartment would not be possible because of over press concerns. However, the low pressurization rate was approved in order to provide more room between the pressure pane and the console dashboard close-out panel.

This procedure was approved as part of the effort to free the knob – which, based on engineering safety margins, had to be removed prior to the next flight of orbiter Atlantis.

Nevertheless, once the knob was removed, an extensive inspection and analysis of the damage induced to the pressure pane from the knob’s edge was undertaken to ensure that flight safety margins on the pressure pane had not been breached.

“Mold impressions were taken and the larger of the defects to the pressure pane measured 0.00035 inches deep,” notes the OPO presentation. “Per the MT0501-514 spec; scratches, dings, and impact with depths exceeding 0.0015 inches are reportable to Design Engineering.”

This proved to be extremely positive news as the defect was not large enough to mandate the replacement of pressure pane #5 – an endeavor that would have taken at least one year to accomplish and could have resulted in Atlantis’ permanent removal from flight status.

Based on mold impressions taken of the damage site, the Micro Inspection Team (MIT) was able to confirm the integrity of the pressure pane and thus clear this issue for flight.

In-Flight Anomalies from Previous Program Flight (STS-128):

Highlighting the remarkable job by ground processing engineers was the near complete lack of IFAs carried forward from the previous program flight – STS-128 and the Space Shuttle Discovery.

In fact, aside from the normal review of the Thermal Protection System (TPS), only two IFAs from STS-128 were discussed during the FRR season for STS-129.

The first of these IFAs was, in fact, a ground issue experienced by the Launch Team during the second STS-128 launch attempt.

“During the transition to reduced fast fill (85 percent), the LH2 (Liquid Hydrogen) inboard fill and drain valve (PV12) closed position indicator (PI) did not come on when the valve was commanded closed,” notes the OPO presentation.

This was a violation of Launch Commit Criteria (LCC) MPS-04 (Main Propulsion System 04). As such, a 48-hour scrub was called and an ambient cycling test of the PV-12 valve performed once ET (External Tank) boil-off was complete.

During the ambient test, the PV-12 valve functioned as designed, with no anomalies detected.

“Data obtained following ET drain, along with historical valve cycle timing and low pressure actuation test data concluded that the failure was most likely the valve position indicator and not a failure of the valve to cycle properly.”

As such, an LCC deviation was accepted by the Mission Management Team (MMT) for STS-128 – which would have allowed for the launch of STS-128 if the Launch Team could have verified the closure of the PV-12 valve even if the sensor issue reappeared.

However, the LCC deviation proved unnecessary as the PV-12 valve and associated sensors worked perfectly during the third and final launch attempt for STS-128.

Post-flight borescope inspections identified “contamination under the close micro-switch arm,” notes the OPO presentation. “Contamination dislodged during removal attempt; other retrieved material consisted of putty with embedded foam and metal shaving.”

Similar borescope inspections were performed on Atlantis, which revealed that OV-104′s PV-11 valve was worn where contact with the actuator cam occurs. There was also a minor “ding” noted on the PV-9 valve.

The PV-9 valve “ding” was accepted for flight, while the PV-11 valve was R&Red.

The second issue from STS-128 brought forward to the STS-129 FRR was that of the Forward Reaction Control System (FRCS) F5R thruster.

“During the initial usage of Vernier RCS (VRCS) on the evening of FD-1, the VRCS thruster F5R fuel and oxygen injector temperatures began to drop. The F5R thruster was deselected as Fail Leak when temperatures dropped below 130 deg F limit.”

In all, there was no indication of “safety of flight” issues and all flight rules were followed during STS-128.

Since the VRCS is not mandatory for ISS/Shuttle rendezvous and docking operations – and since no generic fault could be identified for the failure of the F5R thruster on Discovery – there is no constraint for STS-129 and Atlantis.

L2 members: Documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size.

No related posts.

STS-129 Processing Latest:

Atlantis – housed on OPF-1 (Orbiter Processing Facility) – has a slightly longer flow than normal, as she is reconfigured for International Space Station (ISS) missions.

The removal of her Hubble payload equipment has all but been completed, along with the removal of her three SSMEs, and the replacement of two slightly damaged windows (1 and 7).

“Windows1 R&R is complete less 24 hr re-torque. Window #7 R&R complete,” noted the latest processing information (L2). “Fuel Cell 2 voltage reduction test complete. OMS Pod Functional is in work. S-Band antenna troubleshooting in work.

“Payload download is in work. FRCS (Forward Reaction Control System) functional is complete. Wheel and tire installation continues to be in work.

“Weekend Work: Remove Bay 11 & 12 longerons. Waterproofing Sunday (Bay Clear).”

Atlantis has at least two more missions ahead of her prior to the retirement of the fleet – pending a final decision on shuttle extension – along with the assignment as the STS-135 LON (Launch On Need) support role of the final mission on the current manifest.

Currently targeting launch No Earlier Than November 12, the STS-129 mission will see Atlantis deliver the Express Logistics Carriers 1 & 2 (ELC-1 and ELC -2), along with SASA and MISSE (Materials on International Space Station Experiment) 7A and 7B, to the Space Station.

ASA Root Cause:

Work started on the ASA channel 1 failure – a system required for carrying commands from the flight computers to the aerosurfaces such as the elevons and tail – shortly after Atlantis landed in California at the conclusion to STS-125.

The issue was first registered during SSME ignition, which – it has since been revealed via Flight Readiness Review (FRR) documentation – had the potential to cause a RSLS (Redundant Set Launch Sequencer) hold with just seconds remaining on the countdown.

“During SSME ignition an electrical short occurred on DC buses MN-A and MN-B which resulted in the loss of ASA-1 and caused several MDM (Multiplexer Demultiplexer) FA1 and OA1 measurements to become erratic momentarily,” noted a 260 page Agency FRR presentation from the Orbiter Project, available to download on L2.

“If this failure were to occur prior to T-10s, the result would be a violation of GNC Launch Commit Criteria. If this failure were to occur between T-31s and T-0s, the potential for an RSLS hold or abort exists (however, “Instrumentation shift only – not true cap voltages,” allowed Atlantis to launch and continue to orbit without concern).

“At ~T-3s FC currents indicated a current-limited short of ~12.5A on FC1 (MN A) and ~7.5A on FC2 (MN B). At ~T-0s the short circuit was isolated from the main busses (total short circuit time of ~3s). At ~T+1s the event indicator for APCA4 RPC 10 (10A) transitions from ON to OFF followed by the event indicator for APCA5 RPC 12 (5A) at ~T+2s.

“FC (Fuel Cell) current short circuit signatures were consistent with RPC trip characteristic signatures (150 percent for 2-3s). APCA4 RPC 10 and APCA5 RPC 12 provide redundant power to Aerosurface Servoamplifer-1 (ASA-1). Follow on flight control signatures support loss of ASA-1.”

The short itself was caused by the noise of the SSMEs powering up injecting into Atlantis’ aft, and causing some disruption of Atlantis’ avionics.

“Review of Bus Monitoring Unit (high rate) data showed that during the time of the short circuit a distorted, 400Hz sinusoidal wave was injected onto the MDM FA1 and OA1 signal return buses,” added documentation.

“This resulted in measurements which use the MDM signal return bus as a reference to become erratic (single ended). Differential measurements were not affected. Once the short circuit was isolated all measurements on MDMs FA1 and OA1 returned to expected values.

“Review of historical data uncovered a very similar event during the STS-37 (104 Flight Eight) ground flow (1991). Short circuit was determined to be caused by an exposed conductor contacting vehicle structure on the 26Vac excitation circuit between ASA-1 and a left wing elevon actuator

“Wire was pinched in the non-insulated portion of a wire harness clamp that shorted while personnel were in the area. MDM interference was determined to be due to the grounding scheme of the ASA box.”

In-flight short circuits associated with orbiter wiring are rare, with the previous incident occurring during Columbia’s highly eventful STS-93 launch

*Click image for a clippedd video sample (full video on L2) showing flight controllers reacting to the STS-93 event.*

“There have been seven previous in-flight short circuits which were later isolated to Orbiter wiring damage.

“The last in-flight short circuit isolated to Orbiter wire was the AC-1 phase A short during ascent of STS-93 (1999). This resulted in a stand down period during which all vehicles were inspected for previously undetected wiring discrepancies.”

Following the STS-93 short, corrective actions were implemented that both reduced the potential for wire damage and heightened detection capability should it occur.

“Inspection Processes Enhanced Following STS-93. Wire inspections are now performed by two independent quality inspectors anytime wire bundles or connectors are opened for any type of work (category 1),” outlined documentation.

“Harnesses are flared and a detailed inspection of accessible wire performed with 10X magnification, lighting and mirrors as required. A baseline wire inspection was scheduled to be performed on each vehicle at its next OMM (category 2).

“A hands-on outer-periphery inspection of ALL accessible wire bundles with criteria and methods similar to category 1 intended to capture and repair latent wire damage (i.e. baseline the vehicle).

“Closeout inspection criteria was updated to require two independent inspectors and inspections are now performed prior to installation of hardware that would cover wire. Arms-length inspections of wire bundles are performed as areas are backed out and closed for flight.”

During flight, the failure of the single channel ASA – part of a quad channel system – holds no mission impact. However, due to flight rules, a second failure – depending on the cause – forces a discussion on whether to bring the orbiter home at the next landing opportunity.

Expansive plans were drawn up in the event of a second channel failure, resulting in over 20 presentations to the Mission Management Team (MMT) during STS-125′s mission (all available on L2).

The need to find the root cause of the ASA failure was deemed a priority for engineering teams, although the task was daunting to say the least, due to the amount of wiring that required inspection.

“(The ASA wire network) represents approximately 300 feet of bundled cables or approximately 800 feet of cable end to end,” noted documentation, with initial resistance checks during Atlantis’ stay at the Dryden Flight Research Facility (DFRC) finding no obvious fault candidate.

Working through wiring from the nose of Atlantis, all the way through to connections with the Solid Rocket Boosters (SRBs) and External Tank, sections were cleared one at a time during the investigation, prior to a breakthrough last week.

“ASA 1 Update: Troubleshooting found a Hi-Pot failure in Right Hand inboard Elevon,” noted processing information, relating to a test that applies a higher than normal voltage to the signal wires, with the aim of applying a greater stress to the insulating coverings in order to uncover any weakness.

The voltage is usually applied with respect to system ‘ground’ reference and any excessive current indicates a breakdown of the insulation (due to cracks, damage, etc.)

Root cause for the ASA failure is thought to be a short from one of the power signal wires to ground, and further testing on the associated harness were undertaken to reveal the specific fault.

Updating status, the Orbiter Project Office (OPO) noted observations of worn-through insulation specific to the area in question, adding confidence they have found the cause of the short associated with the ASA-1 failure.

“On the ASA, did find the short and the wire harness was removed. Guys did a good failure analysis on it, and at NSLD (NASA Shuttle Logistics Depot) they could see the worn-through over-braid and the worn-through insulation of the wire below the over-braid,” OPO noted on the latest Shuttle Standup/Integration report (L2).

“They could see the damage from the HPOTP (High Pressure Oxygen Turbopumps), but were able to find a small pit that appears to be the original short location. Have been working with Ground Ops to do the inspections on the other vehicles in similar locations and making sure we have everything protected.”

This associated harness will be replaced with a new version that is being built in time for installation into Atlantis next month. Endeavour was already cleared due to added in-built braiding protection on her wiring.

“At the NSLD, we’ve started the planning and fabrication of a new ASA wire harness to replace the one removed from OV-104 (Atlantis),” added processing notes. “Looking at July 10 as a delivery date.”

L2 members: Documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size.

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Previous Vehicle Flight:

For the review of Endeavour’s previous flight – the STS-126 mission in November 2008 – the OPO identified two issues that gained attention during the STS-127 SSP FRR (Space Shuttle Program Flight Readiness Review) last month. The first issue pertained to TPS (Thermal Protection System) tile and blanket anomalies.

The OPO presentation, available for download on L2, noted that three gap fillers were found to be protruding from the Left OMS pod during post-launch inspections.

During post-flight analysis, the cause of the gap filler protrusions was noted to be a “torn sleeve or bonding issue” that had been noted on Left OMS Pod #3 during previous flights. Flight rationale for STS-127 was obtained for this issue without much discussion.

All three of the protruding gap fillers were still present post-landing and were removed prior to Endeavour’s ferry flight back to KSC in December. An investigation of the gap fillers indicated minimal RTV application/contact to the bonding surface of the Pod.

The Program Data Requirements Resources Team later identified improvements to the bonded process that will ensure full length bonding of gap fillers on future flights.

During Endeavour’s turnaround flow, all OMS Pod leading edge gap fillers (all 260 of them) were “subjected to detailed post-flight inspections for fraying/protrusion.” In all, 34 suspect gap fillers were removed and replaced using “improved fabrication techniques and a more robust pull test of 10 lbs.”

Additionally, the second STS-126 issue to gain recognition during the SSP FRR process relates to Ku-Band Antenna anomalies: specifically, a lack of “tracking” mode during communications operations in General Purpose Computer Acquisition Mode, Multiplexer/Demultiplexer (MDM) FF3 bypass of Electronics Assembly-1 (EA-1), Forward Link Frame Sync Telemetry Dropouts, and flawed RADAR Data during undocking.

The “tracking” mode error self-corrected on FD-15 (Flight Day 15), the MDM FF3 bypass recovered with Guidance and Navigation Computer Input/Output reset, the Forward Link Frame Sync Telemetry Dropouts was an indication only and did not affect Ku-Band forward link operations, and the Ku-Band flawed RADAR Data during undocking affected range, range rate, and angle rate data displayed on Endeavour’s Flight Deck consoles.

The COMM angle track issue was repeated during flow turnaround and was isolated to the EA-1; the MDM FF3 bypass was also repeated and isolated to EA-1.

Furthermore, the frame sync telemetry and flawed RADAR data could not be repeated during Ku servicing. EA-1 was removed and replaced (R&Red), and a complete retest of Endeavour’s Ku system showed no repeat of any of the four errors seen during the STS-126 mission.

However, should any of these errors re-occur during STS-127, there are several workaround options available to Endeavour’s Flight Crew and Flight Control Team.

“Antenna angle tracking can be switched to GPC designate mode, transient conditions resulting in MDM bypass may be recovered with a GNC I/O reset, and alternate methods can be used during rendezvous to provide data normally provided by the Ku-Band radar such as the trajectory control sensor and hand held laser,” notes the OPO presentation.

The OPO also noted that all three of the orbiter’s GH2 FCV (Gaseous Hydrogen Flow Control Valves) have been approved for flight, after they were installed on Endeavour on May 7 at Launch Pad 39B.

Previous Program Flight:

The first issue from STS-125 (the previous program flight) to carry over to the OPO STS-127 SSP FRR was an erratic MPS (Main Propulsion System) Engine 2 GH2 Outlet Pressure Ducer reading.

“At liftoff, the left Space Shuttle Main Engine (SSME) GH2 Outlet Pressure transducer acted erratic,” notes the OPO presentation, adding the Booster officer in Mission Control declared the measurement failed and the crew was informed to disregard the engine out cues as a result of the toggling transducer.

Furthermore, the OPO presentation notes that “during ascent, the Engine 2 GH2 outlet pressure shifted over 1000 psi low.”

All other GH2 Outlet Pressure ducers on the other two engines and the 2” disconnect pressure functioned normally throughout Atlantis’ ascent. At MECO (Main Engine Cutoff), all GH2 Outlet Pressure readings fell to zero on all engines as expected.

Then, “When LH2 repress was activated on orbit (pressurizes LH2/GH2 systems), the 2” disconnect on Engine 1 and Engine 3 GH2 pressures showed 120 psia increase as expected. Engine 2 remained at zero.”

Adding to the investigation is the prior history of failures for this type of transducer – which is used to measure and verify portions of the LH2 Ullage pressure control post-ascent – during fight.

The measurements do not affect engine function on ascent and are used as cues for main engine shutdown, GO2 (gaseous oxygen) out temperatures, and SSME helium tank pressures.

The OPO has concluded, based on previous flight experience, that the ducer issue on STS-125 is not a constraint for Endeavour’s launch as the flight control teams are trained to identify a true ducer measurement v. a false ducer measurement and act accordingly.

Next up in the OPO report was the TPS tile and blanket anomalies from STS-125.

The OPO presentation states that “imagery analysis noted [that] a dark object appears to release from the Left Hand OMS pod” during first stage flight. A review of all pre-flight baseline images and on-orbit inspection images show no discernable gap filler anomalies.

Furthermore, during flow processing for STS-125, Atlantis’ OMS pod gap fillers were inspected for the same gap filler anomalies identified during STS-126. This inspection led to the R&R of one gap filler on OV-104.

Additionally, SRB video captured a gap filler – which was on its second mission and was not installed with the improved procedures identified after STS-126 – migration and liberation event at Mission Elapsed Time 57-seconds.

This particular OMS Pod gap filler event is bound within the flight support analysis conducted during the STS-117 lifted OMS Pod blanket anomaly in June 2007 and thus is not a concern for STS-127. Protruding gap fillers in the same region have been noted previously on OV-105.

As such, all gap fillers in the area in question on OV-105 have been inspected and/or R&Red via the improved process for this flight.

Finally, the OPO presented information on a low chamber pressure in Atlantis’ R5R vernier thruster, specific to “reduced Chamber pressures observed on all firings beginning with vernier activation on FD-1.”

The chamber pressure readings decreased to 48 psia on FD-2 before recovering slightly over subsequent flight days. However, the chamber pressure never returned to its nominal pressure of around 92 psia.

Analysis of all vehicle rate data indicates that the jet performance of the thruster did degrade, noting the thruster “deselected during sleep periods to avoid potential nuisance alarms for chamber pressures below 36 psia at start-up or 26 psia afterward.”

There was no indication of flight safety issues from this issue, and all of OV-105′s vernier jets were confirmed to be in proper working order during the vehicle’s last flight.

The degraded reading from Atlantis’ R5R vernier thruster confirms that the jet is still viable for flight even if the issue should reappear on STS-127. However, “failure of any vernier removes vernier control capability during ISS mated ops,” notes the OPO presentation.

Other attitude control capabilities exist but with potential loss of mission objectives.

L2 members: Documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size.

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Atlantis/STS-129 Latest:

Following her Californian vacation, Atlantis has returned to the home comforts of the OPF in the early hours of Thursday, ahead of a flow that will reconfigure the orbiter for at least two more ISS missions prior to the retirement of the fleet – pending a final decision on shuttle extension, and her current assignment as the STS-135 LON (Launch On Need) support role of the final mission on the current manifest.

“The Orbiter was lifted and the SCA (Shuttle Carrier Aircraft) backed out yesterday at 1226 EDT. Atlantis was spotted in OPF Bay-1 at 0049 EDT (1st attempt) this morning,” noted Thursday processing information on L2. “Orbiter jack and level is in work. The 50-1/2 door removal and aft access are being worked. Tail cone removal is scheduled for 1st shift today.”

Work is taking place on inspecting wiring and avionics electrical hardware related to the Atlantis Aerosurface Servoamplifer (ASA) channel 1 failure, while the small amount of MMOD (Micro-Meteoroid Orbital Debris) related damage to an Orbital Maneuvering System (OMS) pod nozzle has been documented.

Although the MMOD hit was within family, it is large enough to call for the replacement of the nozzle during Atlantis’ processing flow.

Atlantis’ STS-129 mission is currently scheduled as the fifth and final mission of 2009, with a NET (No Earlier Than) launch date target of November 12, delivering the Express Logistics Carriers 1 & 2 (ELC-1 and ELC -2), along with SASA and MISSE (Materials on International Space Station Experiment) 7A and 7B, to the Space Station.

Work has already been taking place for the shuttle elements flying with Atlantis, with the External Tank (ET-133) in a smooth final flow at the Michoud Assembly Facility (MAF), along with the build-up of the RSRM (Reusable Solid Rocket Booster) motors.

“SRM/RSRM (BI-140/ RSRM 108/RPSF): Right Aft Booster Build-up. Aft Tunnel Cable Electrical Check-out is complete. O/I Cable Connect Rooster Tail Aft Feed thru cable connections are in work. O/I Strut Cable Check-Out. Strut cable testing set-up is in work,” added processing information on Thursday.

“NSI Cable Connections and Resistance Checks. Ready-to-Work after Strut Cable check-out. Stiffener Ring Splice Plate Installation. Ready-to-Work after Aft Feed Thru Cable connections are complete. Left Forward Center Segment Offload. Crane repair is complete. Offload Segment today.”

Endeavour/STS-127 Latest:

With the launch date for STS-127 now officially set for June 13, Endeavour is less than a week away from heading into the complex ballet of S0007 (Launch Countdown) procedures out at Pad 39A.

Ahead of that milestone, the STS-127 crew have successfully completed the Terminal Count Demonstration Test (TCDT), ending with the simulated shutdown of the SSMEs at T-4 seconds.

“The Flight Readiness Review concluded yesterday and Saturday, June 13 was officially selected for launch of Endeavour on the STS-127 mission,” noted STS-127 processing latest.

“S0017, Terminal Count Demonstration Test continues today. T-0 is planned for around 1100 EDT this morning. Emergency egress training for the crew (S1025) was completed successfully yesterday. S0009, Launch Pad Validation, is essentially complete.”

However, one issue is being investigated, following the observation of rust-like contamination on two of Endeavour’s SSME nozzles.

“Corrosion/contamination has been noted on two SSME nozzles at Pad A for STS-127 (engines 1 and 3). ME2045 has a significant amount in the first few inches downstream of the MCC/nozzle interface joint G15 (see images below), and ME2054 has a minor amount approximately 10 inches below G15,” added a report on the observations.

“Digital microscope photos of the affected areas will be taken prior to and after cleaning with deionized water and a scrub brush. PWR Canoga Park nozzle engineering and M&P folks will evaluate today.

“These nozzles do get a coat of Sodium Molybdate corrosion inhibitor applied to the hotwall after every flight 1 to 8 inches aft of G15 (for some nozzles, including ME2045′s, it is applied 0 to 8 inches aft of G15). No discoloration was noted on these nozzles following the MCC polishing at Pad B on May 8.

“It is not yet known if nozzle leak checks will be required (possible launch schedule impact). We will have a better idea once we evaluate the nozzle post-cleaning imagery.”

The SSME nozzle tubes are made of A286 iron based steel and are nickel plated primarily to make the brazing of the tubes to operate nominally. It is deemed to be completely normal for these tubes to rust in the Florida coastal pad environment. However, the tubes – which are put under 6000 psig pressure during engine operation – are at risk of rupturing if corrosion has reduced their integrity.

An example of tube damage on the SSME nozzles was seen during STS-93′s infamous launch, where three tubes were damaged by a blown injector pin, leading to the engine controller assuming more hydrogen was being burned and compensated by injecting additional LOX – ultimately resulting in the ECO (Engine Cut Off) sensors shutting down the engines slightly ahead of time, leading to an underspeed at MECO (Main Engine Cut Off).

While Columbia’s engine only suffered from three punctures on her SSME during STS-93, a tube split would be a more serious event, which is why the engines will be inspected and cleared by Rocketdyne ahead of launch.

UPDATE: Leak Checks to take place on Friday.

Discovery/STS-128 Latest:

Over in OPF-3, Discovery is continuing to push through her processing flow, with the milestone of SSME installation being completed on Thursday. Discovery is tracking a launch date of August 7 for her STS-128 logistics mission to the ISS.

“FRCS interface verification is complete. SSME 1 and 3 were installed yesterday; SSME 2 installation is planned for today followed by engine securing,” noted STS-128 processing information on Thursday. “OBSS (Orbiter Boom Sensor System) end effector pre-mate and OBSS thermistor interface tests were both successfully completed.

“MSBLS (Microwave Scan Beam Landing System) waveguide leak checks are planned for today. MADS (Modular Auxiliary Data System) interface verification will be worked today. Orbiter Bus redundancy testing will pick up tonight. A hydraulic operation to perform ET actuator cycling and position aero surfaces is scheduled for tomorrow.”

Discovery is being prepared for a 13 day, three EVA, mission that will include the flight of the TriDAR AR&D Sensor Detailed Test Objective (DTO), the next Boundary Layer Transition (BLT) DTO. Also riding uphill with Discovery will be a new crew member for the ISS – Nicole Stott – as well as MISSE (Materials on International Space Station Experiments) 6A and 6B, SIMPLEX, MAUI, and SEITI.

Aiding Discovery’s ride to orbit will be the Solid Rocket Booster BI-139 (Booster Integration) set, which are currently being stacked in High Bay 1 of the Vehicle Assembly Building (VAB), while External Tank ET-132 is being prepared for mating with the boosters.

“SRB/RSRM (BI-139/ RSRM 107/ VAB/ HB-1): Left Forward Center segment mate is complete. Right Forward Center segment delivery to VAB has been delayed due to weather. No estimate for delivery at this time,” added processing information. “ET-132 (VAB HB-2E) 17” Disconnect Measure/Adjust: LH2 complete, boroscope scheduled for today. LO2 side is in work.”

L2 members: Documentation – from which most of the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size

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RSRM – STS-125 Performance and STS-127 Flight Rationale:

The only issue from STS-125′s RSRMs that carried over to STS-127′s FRR process pertained to the loss of Stiffener Ring foam on the right hand (RH) motor.

“Stiffener ring foam is missing from several areas of the forward, center, and aft stiffener rings on the aft segment of the RH motor,” notes the SSP FRR document available for download on L2.

This type and quantity of stiffener ring foam loss is uncharacteristic of previously observed conditions. Furthermore, evidence from the RSRMs indicates that the majority of the foam loss occurred prior to splashdown in the Atlantic Ocean.

“Evidence of pre-splashdown loss and failure mode are atypical. IFA declared due to uncertain time of foam loss.”

The presentation notes that – during post-flight inspections of Atlantis’ RSRMs – there were “sooted” areas of paint around the missing foam areas.

Foam loss from splashdown forces would not have sooted the external paint. Furthermore, the post-flight inspections also noted adhesive failure at the foam/paint interface.

After discovering this issue, engineers initiated a “fault tree approach” which included the use of forensics, chemical sampling, testing, and “thermal-structural analysis” to identify any special causes that could have contributed to the STS-125 RSRM observations.

Of these special causes, material, processing, and loads/environment have been identified as potential contributing causes to the abnormal foam loss.

With these potential causes in mind, an analysis of future RSRMs is underway to check for any anomalies or abnormalities that may be present.

However, these potential failure mechanisms do not reduce the uncertainty of the time of release of the various foam pieces.

Nevertheless, the FRR presentation notes that defining the liberation mechanism will help identify root cause and contributing factors to the foam release. This, in turn, will help bind potential release times and the effects this type of foam release could have on future flights.

To aid in the determination of the particular time-of-release, NASA analysts conducted a thermo-structural analysis within pre-set bounding assumptions to observe potential release times based on particular failure mechanism.

This analysis will also help identify potential issues Endeavour’s RSRM stiffener ring foam could experience during ascent.

Furthermore, the analysis of potential release times will help imagery and TPS experts understand the risk posed to Endeavour as RSRM foam can travel ‘up’ the stack via the surrounding slipstream of air during launch – an anomaly that was first noticed during Discovery’s STS-116 launch in December 2006.

However, all evidence collected to date suggests that the foam liberation on STS-125 occurred after SRB separation.

“Evidence from multiple sources indicates that foam release on STS-125 was post booster separation,” notes the SSP FRR documents.

There was no indication of foam release through SRB separation from the SRB engineering cameras; all ground-based video from long-range tracking cameras confirms that stiffener ring foam was “intact through mid-burn.”

There were “multiple events” observed by the SRB engineering cameras at 280-seconds that are still under review to determine if they are the foam releases in question or something else.

However, thermo-structural loading, heat flux, and dynamic pressure maximums peak during reentry, lending further evidence that the most likely time of release is/would be during SRB reentry.

Likewise, “sideways orientation, tumbling, or aft end first assessed to be worst case for foam liberation,” notes the RSRM FRR document.

At this time, there are no indications of material or processing anomalies on STS-127′s motors; however, without root cause identified, it is impossible to say for certain whether or not Endeavour’s RSRMs carry the same conditions as Atlantis’ last month.

With this is place, the SSP FRR notes that final flight rationale for STS-127 was still pending as of last week, rationale that was reached today during the SOMD FRR.

Lastly, the SSP FRR document notes that the thrust imbalance observed during STS-125 was within all family limits with no issues going into STS-127.

SRB Modifications for STS-127:

For STS-127, one change will be implemented to the Solid Rocket Boosters (SRBs). This change relates to the incorporation of a 2A fuse assembly into the Power Bus Isolation Supply (PBIS) module.

This change was implemented due to “Integrated Electronic Assembly (IEA) PBIS T2 transformer solder joints susceptibility to fatigue,” notes the SRB FRR document – available for download on L2.

The issue was first presented during the STS-124/BI-134 Certification of Flight Readiness/Mission Management Team meeting and the STS-125/BI-135 Flight Readiness Review last year.

This 2A fuse incorporation comes one flight earlier than expected due to the availability of forward and aft IEAs with modified PBIS cards.

This 2A fuse design “disconnects the PBIS if too much current is drawn.”

The redesign also eliminates all potential criticality 1R failures downstream of fuse associated with PBIS and mitigates the loss of SRB power bus concerns and prevents loss of redundancy for SRB critical functions.

Vehicle Imagery Modifications/Updates:

For STS-127, all crew handheld cameras, ground network cameras, SRB cameras, and the ET LO2 Feedline camera are on track to support the June 13th launch. However, there will be two changes to the imagery ability from STS-125.

The first change pertains to the Forward Skirt Aft Pointing camera on the LH SRB. This camera will be repositioned to match the orientation of the RH SRB camera from STS-125 and STS-120.

This new Forward Skirt Aft Pointing camera configuration – which allows engineers to observe foam behavior in the Intertank region of the ET – has been baselined and approved for the remainder of the Space Shuttle Program.

Additionally, one long-range tracking camera will be moved back to Ponce Inlet (just south of Daytona Beach) from its STS-125 support position in Cocoa Beach.

Furthermore, Endeavour’s Umbilical Well still camera will be Removed and Replaced (R&R) now that she is at Pad 39A. This R&R is expected to resolve the “no flash” and memory buffer problems experienced during pre-flight testing.

Lastly, ET LO2 Feedline camera live downlink through ET/Orbiter separation will be available for all remaining missions due to ISS orbit inclination and launch trajectory.

L2 members: Documentation – from which most of the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size

Related posts:

1. STS-126 launch countdown begins – Atlantis heads back to OPF-1The three day launch countdown for STS-126 has begun, marking...

Atlantis/STS-125 Latest:

Atlantis has enjoyed a mainland US sightseeing tour, taking in Biggs (Texas), Lackland AFB (San Antonio, TX), before heading to Columbus, MS. From there, the duo took the air for the final time, to head into the Florida evening and land at the Shuttle Landing Facility (SLF).

Engineers will begin work at the SLF’s Mate Demate Device (MDD) to remove Atlantis from the modified 747, prior to towing her back to the vacant OPF-1, as she prepares to heads into post flight processing.

However, some work has already taken place during her Californian vacation, notably on the Atlantis Aerosurface Servoamplifer (ASA) wiring and the Flow Control Valves (FCVs).

“Did a little preliminary trouble shooting out at Dryden. They looked down into the wires to see if the short was still there and did not see it. It is still possible there is a short in the wires,” noted the Orbiter Project on the latest Shuttle Standup/Integration report (L2).

“They did not look at the box for additional damage because they did not want to put any additional stress on the ASA. They have revised the ASA flight rationale, and added in more things about the effects of similar types of failures on other systems when the ground plane is affected.

“The team put together a good set of charts over the weekend to describe what we saw, what the implications are to the orbiter hardware, what we’ve done with wiring, and how we handle wiring on the orbiter.”

The hand delivery of the GH2 FCVs to their fabricator “Vacco” allowed for checks to be carried out in a timely fashion. Positive news that no cracks have been observed on the valves has already reported back to the Shuttle Program.

“Got news from Vacco on the FCVs that came out the vehicle. Upon inspection, there are no cracks. They are in the same condition they were before flight,” added the Orbiter Project. “They gave Vacco the go ahead to reassemble those parts. Those are the three FCVs planned for use on OV-103 (STS-128).”

Click here for NASASpaceflight.com articles on the FCV issue since STS-126.

The standup report also listed a couple of items that are of interest for the fleet as a whole, one relating to bent rods on the Manipulator Retention Latches (MRLs) that house the orbiter robotic arms and further interest into the puffs of smoke observed from Atlantis’ Main Landing Gear (MLG) during her touchdown at Edwards Air Force Base.

“Have been doing some trouble shooting on Manipulator Retention Latches (MRLs) since STS-114. During this trouble shooting they found some bent push rods (not the condition they were trouble shooting). Looking at other MRL assemblies, some have been found with slightly bent push rods and others without. Potentially might want to inspect OV-105 at the pad, but these latches are very difficult to get to.

“The story is still unfolding and Orbiter does not plan to talk it at all at the FRR on Wednesday. If needed it will be taken to the L-2 MMT,” added the Orbiter Project, before adding notes about the landing – both issues are not deemed to be constraints for STS-127.

“It does look like when they look at some of the data that some of the brake pulses do indeed line up with some of the puffs of smoke seen off on the right main gear. Appears the braking is very nominal.”

Endeavour/STS-127 Latest:

Despite being one day down on the flow towards launch, Endeavour continues to track a June 13 launch date, although this may still be refined by Wednesday’s Agency FRR.

“Vehicle processing continues to proceed well, although poor weather at KSC has made the schedule very tight,” noted MOD’s 8th Floor News (L2) on Tuesday. “We are still pressing toward a June 13th launch and per the normal process, the launch date will be formalized at the Agency FRR.”

Processing at Pad 39A has been working through the completion of S0009 Launch Pad Validation procedures, as STS-127 heads into the L-10 (day) point of the flow.

“Range Safety first motion checks are complete. SRB HPU (Solid Rocket Booster Hydraulic Power Unit) Bearing Soak is complete. SRB Aft Skirt purge activation and checkout is complete. LO2/LH2 and GO2/GH2 system checkouts are complete,” noted Tuesday processing information on L2.

“Vac Ion pump run is complete. OMBUU (Orbiter Mid Body Umbilical Unit) mate is scheduled to occur Thursday at around 1200L. S0600 payload installation into the orbiter was completed yesterday.”

However, a problem was noted with the 30 year old Fire Extinguisher system (FIXEX), which leaked contaminated water into the area of the shuttle. This is not expected to be a problem for the continued flow towards launch.

“Orbiter Spray and FIREX Check out complete. During FIREX validation the system burped leaking rusty water on the orbiter stinger,” added processing information. “OMS/RCS and TPS engineering inspected the area; engineering evaluation continues.

Other work taking place outside of the normal flow will also involve the replacement of the ET Umbilical Camera on Endeavour – following several fleet wide issues with the system, while preparations move into the Terminal Count Demonstration Test (TCDT), due to take place on Wednesday.

“S0017, Terminal Count Demonstration Test preps continue; the test is scheduled for tomorrow and Thursday. Crew escape poll transferred from Pad B to Pad A, and lifted to the 195′ level,” added processing information.

“On the digital umbilical camera for STS-127, did get a good check out of that camera last week. It is not installed yet. The team did send the camera down, mate that camera up to the umbilical flash, check it out, and the camera is functioning fine. The plan is to install it this week.

“We know that we have a good flash as well. We need to R&R the camera. We have a lot of confidence in the camera for STS-127. A chart will be added to the FRR charts for Wednesday.”

The achievement to even be in a position of launching another mission less than a month after the return of Atlantis from STS-125 should not be underestimated, with the teams earning special praise from Mission Management Team (MMT) co-chair Leroy Cain.

“Great work over the weekend. A lot of activity going on to get ready for STS-127, and also to get Atlantis back to the Cape. Know there were some technical issues, some hardware issues, and weather is always a challenge going across country,” Mr Cain said, addressing the workforce via the latest Standup report (L2).

“With Endeavour at Pad A, it sounds like we’re progressing well towards being able to go fly STS-127 whenever we decide we are ready to go to that; still targeting June 13. We’ll have our FRR on Wednesday. A lot of working going on over the weekend associated with some of the open work that we have, some of it open paper, some of it open work from a technical standpoint.

“Want to remind you and really urge you to please make sure that folks are getting a little down time. STS-127 is an extremely complex mission, and will require all of our focus. It will require as much or more due diligence that we’ve ever demonstrated.

“It is going to be a very exciting mission. It is going to be very challenging as well. Let’s make sure we get ourselves and our folks rested to the extent that we are able to. We’ve got a big week in front of us. Go get’em.”

L2 members: Documentation – from which most of the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size

Related posts:

1. Dual flow ballet for Endeavour and Atlantis – De-stack debatePreliminary milestone schedules have been created for the complex dual...
2. STS-126 launch countdown begins – Atlantis heads back to OPF-1The three day launch countdown for STS-126 has begun, marking...
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With Atlantis riding on top, the modified 747 SCA (Shuttle Carrier Aircraft) was reversed out of the MDD (Mate Demate Device) at 4:43am local time, with a departure around 8am local on Monday - following approval by the Ferry Flight Readiness Review (FFRR).

Tuesday Update: Based on weather, the current plan on Tuesday involved heading to Lackland AFB (San Antonio), before heading to Columbus, MS, prior to an eventual arrival back at KSC around 6pm local time.

Refer to live update pages for the latest information.

Dryden farewell:

“Teams are preparing space shuttle Atlantis for its cross-country ferry flight from California to Kennedy,” noted a memo to KSC workers earlier today. ”Atlantis is mounted on top of a modified Boeing 747 and is expected to depart Edwards Air Force Base at 11 a.m. EDT (8 a.m. PDT) today.

“The ferry flight will travel to Biggs Air Force Base in El Paso, TX and will stay there overnight before continuing the trip to KSC. Weather permitting, Atlantis could be back at its Florida home Tuesday night.”

Bar a slight problem during mating late on Sunday, all remaining closouts were completed without issue.

“Orbiter: OV-104 / Landing – Edwards AFB Turn Around Operations: Post Landing Ops Completed Over the Weekend: MPS (Main Propulsion System) decay checks. The 44 door and the drag chute door installations. Platform removals,” noted Monday processing on L2.

“The Ferry Flight Readiness Review; the team was given a ‘GO’ to proceed. The lift onto the Shuttle Carrier Aircraft (SCA). The Ferry flight is scheduled to depart Edwards AFB soon after completion of the Weather Briefing scheduled for 0600 PDT this morning.”

The results from the initial testing of Atlantis Aerosurface Servoamplifer (ASA) wiring have come back with no obvious issues. The failure of ASA Channel 1 as STS-125 launched held no mission impact, but a root cause would be deemed as helpful, as managers meet this week at the STS-127 Agency level Flight Readiness Review (FRR).

“ASA-1 initial troubleshooting for IPR-0002; no anomalies were found in orbiter wiring,” added Monday’s processing, with further testing scheduled for when Atlantis is back inside the Orbiter Processing Facility (OPF) at the Kennedy Space Center.

More will follow.

ET-130 IFR Review:

Also part of STS-127′s FRR is the IFA (In Flight Anomaly) of the foam loss observed from Atlantis’ External Tank (ET-130) during STS-125. While ET-130 was yet another “clean” tank, the loss of foam from the LOX Ice Frost Ramp (IFR) occurred during the “dangerous” period of ascent, where resulting impacts have the potential to cause damage.

The liberation did strike the orbiter, but only caused minor damage on her starboard Chine area of her Thermal Protection System (TPS). The damage failed to expand during the return home, backing up the DAT (Damage Assessment Team) findings the damage was of no concern.

Regardless, the foam loss made up the majority of Lockheed Martin’s ET IFA (STS-125) and FRR (STS-127) documentation (all available to download on L2), mainly thanks to the lack of other issues, and also to provide further understanding of the risks associated with similar foam liberations over the remainder of the shuttle program.

“STS-125/ET-130 post flight performance assessment in-work: Prelaunch and preliminary post launch assessments to be summarized. No constraints to STS-127 launch identified to date,” outlined the FRR presentation.

“ET-132 identified as STS-127 LON tank: First implementation of FSW welding on LH2 tank barrels 3 & 4 (longitudinal welds only)/ Provides more robust and producible design. Nominal processing with no issues for STS-127 LON (Launch On Need) requirement.”

Specific to ET-130, the presentation outlined that the tank performed as expected, with only four areas of foam loss observed imagery – which was initially gained from handheld photography, due to the failure to download the ET Umbilical Well camera footage. That footage has since been manually downloaded, following Atlantis’ arrival in California.

“Pre-launch Performance Assessment: All ET systems performed nominally – No (criteria) violations. No leakage observed at hydrogen vent system ground interface. Typical TPS observations acceptable per (requirements),” added the presentation.

“Post Flight Performance Assessment: Structural, electrical, and MPS systems performed nominally. TPS system performed nominally. Four (4) foam loss events observed in imagery review. Debris size / timing consistent with expectations

“One item observed to impact Orbiter chine at 104 secs. LO2 IFR debris location Xt 718 possible cause of damage. Time of release not observed but expected based on physics-based understanding of design and failure mode (void / delta pressure). Chine impact at 104 sec also observed via SRB video (multi piece event).”

Lockheed – who operate the Michoud Assembly Facility (MAF) in New Orleans – presented assessments related to the mass of the liberation, and any potential manufacturing changes that may have led to the foam shedding event. Importantly, the mass of the shedded foam was well below the risk assessment numbers.

“Performance consistent with physics-based understanding of hardware / failure mechanism (PDL pour with void/delta pressure divoting). Conservative mass estimate below risk assessment mass limit (0.020 lbm). 0.007 lbm max debris mass conservatively assuming single piece release.

“Assumed 104 secs MET time of release consistent with analytical prediction. Divoting potential starts at 95 secs. (combination of external heat and vacuum loading). Imagery and test data review support multi-piece liberation event. Review of SRB video shows additional debris observed within 1 sec. of chine impact with similar trajectory.

“Review of previous ascent imagery and test data shows successive foam release likely for PDL material. Thrust strut flange on STS-117 and LH2 IFR thermal / vac tests

“Reviewed ET-130 configuration, processing and repair history. No unique events or changes identified for STS-125. Design and process previously flown with no debris. Process revalidated since RTF – 3rd flight following re-validation of application process.”

“Performance consistent with debris cloud inputs and results used in integrated Probabilistic Risk Assessment (PRA). Divoting potential starts at around 95 secs. Largest single piece (assuming multiple events) ~< 0.007 lbm and consistent with debris cloud expectations (~0.005 lbm).

“Documented observations less frequent than predicted by debris cloud. 17 void / delta pressure debris events < 0.010 lbm expected per flight. Two debris events (divots) observed since RTF (XT 634 & 718). Erosion / popcorning typically observed on forward ramps due to high heating environment.”

Thanks mainly to the low mass of the liberation, the event will not require any further investigation.

“Summary / Forward Plans: Performance assessment results show all ET systems performed nominally. Four (4) debris events observed in umbilical well imagery. Mass estimates in-work but expected to remain below risk assessment mass limits. Time of release within expected performance for all observed losses.”

The performance of the External Tanks since the PAL ramp liberation event of STS-114 has been nothing short of spectacular. Several phases of redesigns – mainly focusing on reducing areas of foam on the tank that has the potential to shed and impact the orbiter – have proved to be highly successful.

ET-130 – despite the IFR event – can be added to the list of successes.

L2 members: Documentation – from which most of the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size.

Related posts:

1. Atlantis to rollback to VAB on October 20 – Hubble troubleshooting latestAs NASA and the SSP (Space Shuttle Program) refine their...
2. STS-126 launch countdown begins – Atlantis heads back to OPF-1The three day launch countdown for STS-126 has begun, marking...
3. Dual flow ballet for Endeavour and Atlantis – De-stack debatePreliminary milestone schedules have been created for the complex dual...

Atlantis Latest:

The SCA/Atlantis duo were set to leave California on Sunday, before a couple of weather related delays in the flow forced managers to change the schedule on Friday night, with departure from Dryden moved to no earlier than Monday.

It was the unusual occurrence of storms in the desert region where Atlantis landed at the conclusion of STS-125 that interrupted the timeline for the installation of the tailcone that surrounds the orbiter’s aft hardware to reduce drag during the piggyback journey across the States.

“Post Landing Ops: Facility Power breakers are still operating nominally. EMUs are removed and the airlock is closed. Tile post flight inspections complete. Pyro Safing is complete. Fuel cell purges are complete. Water drain was completed. Eight orbiter side tailcone fittings are installed,” noted processing information on L2.

“SCAPE operations for hyper de-servicing were completed. Shuttle Carrier Aircraft (SCA) polarity checks were successfully completed.”

The removal of the support structure – used for the mating of the tailcone to the orbiter – was also slightly problematic, due to tight clearance margins between the structure and Atlantis’ body flap. Final work involved the retraction of the landing gear and the closure of the associated doors.

This marked the end of hydraulic operations and tailcone installation work, with Atlantis scheduled to be raised on the MDD (Mate Demate Device) at 8am (local time) on Sunday, before the converted 747 takes its position below the orbiter at 10am. The rest of Sunday will be dedicated towards the mating of Atlantis on top of the SCA.

This will be followed by the Ferry Flight Readiness Review (FFRR), which will also plan out the route the SCA/Atlantis duo will take over the mainland United States, resulting in an arrival back at the Kennedy Space Center (KSC) – depending on weather – sometime on Tuesday. Refer to the live coverage pages for updates.

Other work that has taken place during Atlantis’ Californian vacation includes the removal of her GH2 Flow Control Valves (FCVs), which allowed for delivery to the valve’s contractor, Vacco, to be checked for any cracks that may have been suffered during Atlantis’ launch.

Click here for NASASpaceflight.com articles on the FCV issue since STS-126.

“In support of OV-104, the FCVs will be hand-delivered to the vendor. Once there, they will go through eddy-current testing,” noted the latest Shuttle Standup/Integration report on L2, although it has been noted that ascent data pointed towards no issues with the valves during the STS-125 ride uphill.

Earlier in the pre-Ferry flow, engineers also took the opportunity to begin testing of the Aerosurface Servoamplifer (ASA) wiring, following the failure of one of the four channels on STS-125 – caused by the noise of Space Shuttle Main Engine (SSME) ignition.

“The DFRC (Dryden Flight Research Center) team has been directed to perform ASA #1 (IPR 129V-0002) troubleshooting,” added processing information. “The plan was to take resistance measurements on the orbiter wiring and into ASA #1. The vehicle was then reconfigured for ferry flight.”

Further testing will take place inside the Orbiter Processing Facility (OPF) once Atlantis has returned to KSC, which will hopefully result in additional data for STS-127′s flight rationale when managers meet for the Agency Flight Readiness Review (FRR) next week.

Atlantis is departing at 8am local time on Monday and heading to Biggs, Texas on the first leg of her journey.

Endeavour Latest:

Back at KSC, Endeavour swapped pads from 39B to 39A, which will mark the end of shuttle operations at 39B, prior to being turned over for the Ares I-X launch (date remains under review). Endeavour had taken vacancy of 39B for the STS-400 LON (Launch On Need) requirement in support of STS-125.

Now in a tight flow towards the STS-127 launch date, Endeavour was backed out of STS-400 processing, which involved the removal of the ordnance, to be reinstalled once she’s on Pad 39A. However, a large amount of STS-400 pad flow work already conducted on the stack, which removes around two weeks of processing from the STS-127 flow on Pad 39A.

“S0024 Prelaunch propellant servicing was completed. S5009 Ordnance disconnects in preparation for roll to Pad A completed. S0038 preps for roll-around to Pad A began Thursday. First motion to Pad A is now planned for 0001 hrs on Sunday,” noted processing information on L2.

“S0017 Terminal Count Demonstration Test has been rescheduled to Wednesday/Thursday next week to provide additional time to complete the above work. Preparations continue at Pad A for OV-105 (Endeavour) rollover/rollaround, currently scheduled for Sunday.”

The scheduled start time for first motion was delayed for several hours, with a requirement to back out and realign the Crawler Transporter (CT) under the Mobile Launch Platform (MLP) twice. The stack eventually started to depart the pad shortly before 2:30am local time.

Endeavour arrives at a repaired Pad 39A, following damage sustained to several areas of the pad during STS-125′s launch, mainly on the Solid Rocket Booster (SRB) flame deflector. Around two weeks of repairs took place on the trench, which required a new coat of fondu fyre refractory concrete.

None of the resulting debris from the flame deflector held any risk of impacting the shuttle during launch – although it gained a large amount of documentation in the STS-125 IFA (In Flight Anomaly) and STS-127 SSP FRR (Space Shuttle Program Flight Readiness Review) presentations.

“Flame Deflector Repairs standard turnaround operation. West SRB side is typically damaged. The direction of STS-125 liberations were within model predictions. Areas of liberation was identified as non-mandatory repair,” noted the opening page of the damage overview in the STS-127 SSP FRR presentations (30 of which are available on L2).

“Actions Taken/Planned: Inspection complete – looks for cracks and dislodged pieces – repairs identified. Additionally, tap testing for hollow sounding areas is performed (complete) – historically, hollow areas were trended for growth, if growth then repaired (complete).

“Hydro-blasting in preparation for new application is a recent enhancement (complete). All priority levels of damage on SRB deflector including hollow areas are to be repaired prior to STS-127 (complete).

“Agreement with STS-127 Payload Customer allows for application after Payload to Pad A and is inside PCR (Payload Changeout Room) with PCR doors closed (complete. “Study in work with Orbiter to capture and investigate concerns with potential TPS contamination if future application required concurrent with STS at Pad. Sampling and testing are planned.”

The force of Atlantis’ launch also damaged several pneumatic lines at the pad, which have also been repaired ahead of STS-127′s arrival at the pad on Sunday.

“LH2 North Bridge Disconnect Tower Pneumatic Line Damage: During STS-125 launch Fondu Fyre Debris liberation impacted various tubing/lines on NE pad surface near MLP (Mobile Launch Platform) post #1.

“No line ruptures or leaks occurred. GH2 line could have been isolated. Repairs were required prior to STS-127

“Action Taken/Planned: Repairs Complete. Fabrication of lines and welding of lines and x-rays. Welding of new supports. All areas are now per print, no deltas.

“Investigation in work to identify all similar commodity and communication service lines that are at risk for similar damage. Review for susceptibility for damage, LPS visibility, isolation and safing capability to be carried out.”

Despite the successful completion of repairs – which was never in any doubt to support STS-127′s launch date – Sunday’s rollover places Endeavour’s flow at minus one day on available contingency for a June 13 launch.

Although the launch date won’t be set until next week’s Agency FRR, Mission Management Team (MMT) co-chair Leroy Cain and SSP manager John Shannon understand they face a challenge to be in a posture that will allow for three launch attempts.

However, as is typical of their management style, if they are forced to slip, “so be it”, as the Program works to a mantra of “safety first”.

“The STS-127/2JA SSP FRR went well. The team at the launch site is working extremely hard to get Endeavour ready for this mission,” added the Standup. “Let us be sure to stay within our processes, to ensure safety at all times.

“At the end of the FRR yesterday, John Shannon remarked on the challenges we face to get to a launch date of June 13. Mr. Cain reiterated that we have just come off of an extremely challenging mission where everyone performed in an outstanding manner. We need to stay focused, exercise due diligence in everything we do, and maintain the rigor we have in our processes.

“If we have to slip the launch date to fly safely, so be it. First and foremost, we need to be taking care of our people. Rotate in your deputies and backups as needed so people get some downtime. There is no more important launch than the next one, so please be considerate of your people.

“If there are any concerns, do not hesitate to push them forward. It is management’s job to be sure that we have done the things that need to be accomplished, so the Program is ready to fly.”

L2 members: Documentation – from which most of the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size

Related posts:

1. Dual flow ballet for Endeavour and Atlantis – De-stack debatePreliminary milestone schedules have been created for the complex dual...
2. STS-126 launch countdown begins – Atlantis heads back to OPF-1The three day launch countdown for STS-126 has begun, marking...
3. Atlantis to rollback to VAB on October 20 – Hubble troubleshooting latestAs NASA and the SSP (Space Shuttle Program) refine their...