STS-132 Status:

The opening landing opportunity called for the deorbit burn to occur at 7:41am Eastern, resulting in a perfect landing on runway 33 at the Shuttle Landing Facility (SLF) at 8:48am.

The second – and final – opportunity would have been available one orbit later, with the deorbit burn at 9:17am for a landing at 10:22am. However, this was not required, along with EOM+1 (End Of Mission plus one day),  and “pick em” day on Friday, when the Edwards Air Force Base (Dryden Flight Research Facility) would have been brought into the mix.

Some level of troubleshooting was worked on the Flash Evaporator System (FES), which will control Atlantis’ temperatures after the Payload Bay Doors (PLBDs) are closed, removing the radiator’s ability to cool electronics and other systems on the orbiter. This issue was soon resolved, allowing for the closure of the PLBDs.

It’s been a smooth couple of days since undocking from the International Space Station (ISS), with Late Inspections enjoying a nominal survey – following the EVA work to free the Pan Tilt/Unit (PTU) on the Orbiter Boom Sensor System (OBSS).

With the Damage Assessment Team (DAT) working on both imagery and data taken during the inspections early in the mission – and the completion of coverage that had been missed via the lack of ability to angle the Laser Dynamic Range Imager (LDRI) over parts of the Wing Leading Edges (WLE) – engineers took just over a day to work through the hours of footage.

The results of the Late Inspections showed an extremely clean Atlantis, and a good argument for her being classed as the cleanest orbiter in at least recent history, with only 252 ROIs (Regions Of Interest) – areas that need any checks, such as scuffs and stains – a number which is the lowest since the use of the OBSS, and nearly half the number observed on STS-131.

“LESS/RCC team cleared all late inspection regions of interest. Level 1 review by PRT completed at 5:00 pm (5-24). Level 2 completed at 1:00 am. Final PRT Review completed at 6:52 am (5-25),” noted the DAT findings presentation (L2). “No ROI exhibited any damage characteristics. From all of the early/late inspection LDRI imagery LESS PRT is GO for entry.”

The robotic duo responsible for the survey – the OBSS on the end of the SRMS (Shuttle Remote Manipulator System) – were successfully reberthed in the Payload Bay for the return home, marking the end of their operations for the mission.

“On FD 11 (Flight Day 11), the OBSS and RMS were successfully berthed, latched, and stowed and are in a good configuration for payload bay door closure, entry, and landing,” noted the Mission Evaluation Room (MER) report on L2.

“OBSS BERTH and MRL LATCH. Did not receive the Aft MRL Latch 2 indication (known condition), no further action required. All other indications nominal. Good single motor drive time RMS BERTH and MRL LATCH – All indications nominal, good dual motor drive time.

“RMS MPM STOW – All indications nominal, good dual motor drive time. OBSS MPM STOW – All indications nominal, good dual motor drive time. The OBSS was stowed on the Stbd MPM by the SRMS. RMS Cradled and powered-down.”

Flight Day 12 involved checks to Atlantis Flight Control Surfaces (FCS), ahead of their use during Atlantis dive back into the atmosphere – which was successful from a hardware standpoint.

“FCS C/O (Check Out): All APU 1 (Auxiliary Power Unit) parameters were nominal during the FCS checkout run. APU 1 run time and fuel consumption are listed below,” added the MER report. “Start time: 145/07:47:03. Stop time: 145/07:45:21. Run time: 3:18. Fuel Used/Rate: 12 lbs; 3.64 lb/min.

“FD12 Performance: All APU parameters are nominal. All APU heaters are functioning nominally on the ‘B’ string. The GG heater lower set point shift – unique to OV-104 (Atlantis) position #1 since STS-81 – is evident after about six ‘B’ heater cycles, exactly the same as on the previous OV-104 mission, STS-129 (31). This heater signature was expected and will be noted in the MER trending database.”

STS-132 Specific Articles: http://www.nasaspaceflight.com/tag/sts-132/

During the FCS checks, Atlantis’ elevons and Rudder Speed Brake (RSB) were put through their paces, ahead of their use for landing, via the use of hydraulic actuators and valves.

“All Elevon Actuator Switching Valves and the RSB PDU Switching Valve were verified to configure to the proper positions (All Elevon Switching Valves to Standby 1 & the RSB PDU Switching Valve in Primary).  Priority valve cracking time was 0.393 seconds (spec ≤1 sec). The HYD System #1 bootstrap accumulator was 2336 psia prior APU #1 start and re-seat pressure was approximately 2832 psia (spec: GT 2675 psia).”

The Mission Management Team (MMT) were also presented with imagery analysis of what appears to be two Foreign Object Debris (FOD) leaving Atlantis during the FCS C/Os.

“(Object 1): Object estimated size: 0.46”. Appears to from bottom of FOV (Field Of View – assumed to emerge from inside Payload Bay). Distance from Camera B to sill of payload bay is 32 inches. 32 inch range (max) estimated to object. No extensive dynamic analysis produced,” noted a MMT presentation (L2).

“Object estimated size: 0.44” – Does not emerge into provided FOV from bottom, so there is not evidence as with the other FOD that it emerged from the PLB. However, it is first seen against the wing background (i.e. it’s much closer than the wingtip on first appearance. Estimate above assumes that it did come from PLB. 32 inch range (max) estimated to object.”

Both objects appear to be similar, but have not been identified. However, no concerns were raised by the MMT, and such debris events can occur during the vibrations of FCS checkouts.

“The Flight Controls System Checkout was performed. The procedure was completed with nominal results. The team is not working any issues,” confirmed the MER via their latest shift report, reviewing Flight Day 12′s activities. “Monitored FCS Checkout and RCS Hotfire. Two Foreign Object Debris (FOD) items were observed floating away from the Orbiter during FCS checkout.

“Imagery personnel recorded video of the FODs, and did not feel that they would pose a threat to the Orbiter TPS, since they were small (<1″), appeared to originate from the upper surface of the Orbiter and were floating away from the vehicle.”

Also included in the Flight Day 12 activities were the firing of Atlantis’ Reaction Control System (RCS) thrusters – including the L3D thruster with its failed heater, successfully mitigated via a passive thermal mitigation plan.

“38 of 38 primary thrusters have been fired. Thirteen (13) new Primary thrusters were fired since previous report,” noted the MER. “All thermal systems are performing nominally (except L3D thruster heater) and temperatures are within acceptable limits. The L3D temperatures are currently near 56F.”

No related posts.

The Mission Management Team (MMT), with information from the DAT and OPO (Orbiter Project Office), officially cleared Atlantis’ TPS for reentry – following a long and arduous process of gathering all the necessary inspection data via Atlantis ‘Orbiter Boom Sensor System (OBSS), R-bar Pitch Maneuver (RPM) photography from ISS, and EVA (Extravehicular Activity) photography opportunities.

In all, the complete inspection of OV-104′s TPS revealed an extremely clean vehicle – aided in large part to the excellent performance of Atlantis’ External Tank which experienced very minor foam liberations during the May 14 launch of STS-132/ULF-4.

“Imagery review complete: 4 items in TIIMS were evaluated,” notes the short, 19-page comprehensive DAT presentation – available for download on L2.

In particular, the DAT identified one area of OMS (Orbital Maneuvering System) Pod blanket damage, two lower surface (underbelly) tile damage locations, and one AMES Gap filler protrusion.

Furthermore, no damage was identified at Atlantis’ port and starboard T0 umbilicals.

The presentation moreover notes the tremendously successful effort by Atlantis’crew to obtain all TPS imagery data in a timely manner given the OBSS’s PTU’s (Pan-Tilt Unit’s) inability to maneuver to the proper positions during initial TPS inspections on FD-2 because of an errant cable.

“Missed port imagery Upper LESS carrier panels 7-9 and Chine tiles, ~150 upper surface tiles.”

The errant cable was removed as an obstruction to the OBSS’s PTU during EVA-2 and all late-inspection imagery was obtained without issue on FD-11.

However, Station and EVA assets that were used to complete the necessary coverage of the TPS tiles by FD-5 of the mission, which resulted in a DAT and OPO recommendation to clear the TPS (save the RCC – Reinforced Carbon-Carbon – panels) for reentry.

STS-132 Specific Articles: http://www.nasaspaceflight.com/tag/sts-132/

Specific DAT TPS Clearance Review:

As is standard in the post-Columbia era, Atlantis’ R-bar Pitch Maneuver (RPM) just prior to docking with the International Space Station provided valuable data on the health of her underbelly TPS – specifically, verification of ET Umbilical door closure.

“Lighting and viewing angles sufficient for assessment of forward edge,” notes the presentation. The paint stripe used to verify ET door closure was – as expected – not visible from RPM photography, confirming Atlantis’ computer data that the ET doors are closed and properly sealed for entry.

“Closure indicators not visible in imagery and no evidence of off nominal steps or thermal barrier protrusions [are present]. ET Doors are closed.”

Interestingly enough, all TPS damage locations for STS-132 are located on the port (or left-side) of Atlantis, with the two tile damage areas located on the port Nose Landing Gear Door (NLGD) and just outboard of the left-aft corner of the Port ET Umbilical door (and just inboard of the forward, starboard corner of the inboard Elevon), respectively.

For the damage location on the NLGD, the DAT summary notes that the tile in question is 1.7-inches thick with a missing “putty repair” of 1.2-inches in length, 0.6-inches in width, and 0.1-inches in depth.

Resulting damage dimensions are estimated at 1.89-inches in length and 0.49-inches in width with “photogrammetry determined depth [at] 0.2-inches.”

This damage area is of no concern for entry and was cleared using P-DAT.

The second tile damage location was similarly cleared using the Port Wing Tile Damage Analysis Tool, which includes the Peer Reviewed categories of Baseline Heating, Cavity Heating, Thermal Analysis, Tile Stress, and overall Stress.

These tools yielded “high” confidence in the damage analysis to the tile in question. Overall, this tile is 1.15-inches thick with photogrammetry damage estimated at 2.25-inches long, 0.97-inches wide, and 0.15-inches deep (+/- 0.05-inches).

However, clearance of this tile damage could not be had without consideration of the upstream AMES Gap filler which could affect the airflow and local heating environment around the damaged tile.

“Thermal analysis performed with STS-132 EOM M18 (Mach 18) heating due to upstream AMES gap filler,” notes the presentation.

For this protruding AMES Gap filler, “Thermal bounded by previous analysis that showed transition at M=18 (keq=.25) acceptable in this area,” notes the DAT summary.

Furthermore, a “Partial transition load comparison based on aeroheating heat loads” was performed as well.

A reference point to a previous analysis “which used partial transition load cases” developed for nonstandard processes was also used to clear the gap filler itself.

In all, the AMES Gap filler is protruding 0.24-inches (+/- 0.15-inches) in a non-reworked area of Atlantis Gap fillers located inboard of the Port Main Landing Gear Door (MLGD).

Since most of the Gap filler remains in the gap, liberation during reentry is not expected as ascent loads on the Gap filler are “several times higher than entry loads.”

Furthermore, considerable flight history with protruding Gap fillers is on file and was used to clear the Gap filler.

In fact, a chart of the historical Gap filler protrusions since Return to Flight in July 2005 showed three Gap filler protrusions with comparable or greater protrusion Height Maximums (Hmax); STS-124: Hmax= 0.23-inches; STS-120: Hmax= 0.29-inches; and STS-121: Hmax= 1.04-inches.

However, given the range of height uncertainty (+/-0.15-inches) with this particular Gap filler, it is possible that the Gap filler could trip the Boundary Layer at Mach 18 during reentry, creating a potential off-nominal heating effect on downstream areas of the vehicle, most notably the damage site of damaged TPS tile #2.

Therefore, while the Gap filler itself was cleared for entry, its affect on the lower surface aft TPS tile damage location had to be evaluated before that TPS tile damage site could be cleared for entry.

In all, it was determined that if the boundary layer is tripped at March 18 by the protruding Gap filler, the structural area directly below the damaged tile would see temperatures below 350˚F with just a small potential RTV overtemp: 2.79in2 normal flow.

Maximum structural temperature expected in the region is 246˚F, only 6˚F above the standard 240˚F baseline temperature.  Therefore, positive structural margin is maintained and no concern exists for the damaged TPS tile due to upstream affects from the protruding Gap filler.

Finally, the last area of Atlantis’ TPS to come under scrutiny from the DAT was a partially frayed outer layer on one FI blanket on the Port OMS pod.

The blanket in question is 1.6-inches thick and all blanket insulation remains intact – thus, thermal performance is maintained. Liberation is not expected due to previous experience with “frayed outer covers and loose patch repairs.”

Currently, it is believed that the blanket was damaged on the ground during final vehicle configuration for flight as the blanket is located next to a door that is removed each flow for access inside Atlantis.

In all, the extremely clean nature of Atlantis’ TPS tiles has led to the unanimous decision by the OPO and DAT to recommend the TPS tiles and blankets cleared for reentry.

Final clearance of the entire TPS (including the all-important RCC panels and nose cap) was approved earlier this morning by the MMT following a complete review of the RCC Wing Leading Edge panels and nose cap imagery from the OBSS late-inspections yesterday.

Thus, weather permitting, Atlantis has been cleared for her final landing at the Shuttle Landing Facility (SLF) Wednesday morning.

If all goes according to plan, Commander Ken Ham will ease Atlantis onto runway 33 (the southeast to northwest approach to the SLF) at the Kennedy Space Center at 0844 EDT, capping a near 12-day flight for Atlantis and the STS-132/ULF-4 mission.

Related posts:

1. Endeavour and her SCA piggyback ride arrive in Louisiana, via JSC flyover The Shuttle Carrier Aircraft (SCA) and Endeavour departed from Edwards...

L3D Thruster Heater Failure Overview:

Following a week of docked operations, orbiter Atlantis has completed her 11th and final docked mission to the International Space Station, capping an amazing career of 18 total dockings to MIR and the ISS (7 to MIR and 11 to ISS).

Currently, Atlantis will spend two more days in Low Earth Orbit, with the all-important late-inspection of the ship’s RCC (Reinforced Carbon-Carbon) WLE (Wing Leading Edge) panels and Nose Cap occurring on FD-11 (Monday). Then, on FD-12, Atlantis’ crew will begin preparing their ship for reentry by testing the various systems they will use for Entry, Descent, and Landing and reconfiguring Atlantis’ middeck for entry.

Finally, on FD-13 (Wednesday), Atlantis will – weather permitting – return to her home at the Kennedy Space Center with a mid-morning landing at the Shuttle Landing Facility.

However, Atlantis’ crew may have to place Atlantis into a slightly different orientation during certain portions of the post-undock timeline to accommodate the need to maintain thruster L3D’s temperature since that thruster’s heater has failed “off.”

According to the Mission Evaluation Room (MER), the L3D thruster heater failure is classified as MER-02 – or the second MER problem recorded during Atlantis’ STS-132/ULF-4 flight.

“Following initial thruster firings associated with ET Sep, both thruster L3D’s fuel and oxidizer injector temperatures reached 59 and 60 deg F, respectively, at ~135/20:08 GMT with no sign of thruster heater activation,” notes the MER presentation – available for download on L2.

Both the L2D and L4D thrusters – the adjacent thrusters – performed nominally with standard heater activation when their injector temperatures reached ~75 deg F.

For the L3D thruster, a temperature of ~60 deg F was maintained until FD-2 when, during the NC-3 course adjustment burn, the L3D thruster fired twice – thus raising the thruster temperature to 72 deg F.

“From the observed rate of temperature decline (approx. 1 deg/hr) the jet temperatures were not predicted to drop low enough to produce thruster leakage or trigger a Fail Leak RM alert overnight; therefore, no vehicle attitude or jet priority changes were performed prior to Crew Sleep,” notes the MER document.

During the on orbit overnight hours, the L3D thruster temperature dropped to 62 deg F and thermal analysis indicated that the thruster temperature would not drop to “leakage” temperatures. This, coupled with the standard thruster jet firings for rendezvous and docking, brought the thruster temperature to over 100 deg F.

The thruster temperature is important because, while the thruster valve design is certified for operations as low as 40 deg F, the thruster valves are known to leak at temperatures below 50 deg F.

“For a failed off heater, thermal analysis has shown that the valve temperature is ~ 5 deg F warmer than the injector temperature instrumentation,” notes the MER-02 problem report. Because of this finding, an OMRSD requirement was instated (back in the 1980s) to ensure that the thruster valve temperatures are maintained above 50 deg F during ground processing – a rule carried over into on orbit operations.

STS-132 Specific Articles: http://www.nasaspaceflight.com/tag/sts-132/

Potential L3D Thruster Forward Actions:

For the thruster on Atlantis, the document notes that the next worst case failure would be a ‘Fail Leak.’ “Sufficient redundancy exists – two other thrusters on the same side and direction (L2D & L4D) – such that no special procedures are required.”

Nonetheless, should a leak occur, the propellant loss or contamination could be staved by closing the L3 manifold isolation valves.

“Per flight rule C2-2C, the manifold would be closed immediately regardless of the injector temperatures if the jet is suspected to be leaking due to contamination concerns.”

Closure of the manifold would result in the loss of the L3L and L3A thrusters as well as the L3D thruster; however, two redundant thrusters would still be available in each of the affected directions.

Failure of the L3D thruster during the docked portion of the mission was negated due to the mated beta angle which prevented the L3D thruster temperature from dropping below approximately 50 deg F.

However, a greater degree of uncertainty exists in the post-undocking timeframe. “Drain panel heater cycling, which warms L3D injectors about 4F per cycle, is expected in the post undocking -ZLV -XVV attitudes, but the exact duty cycle is hard to predict due to several attitude changes,” notes the MER document.

Due to these uncertainties, temperatures as low as 40 deg F could be had in the post-undocking timeframe.

However, “Thruster temperature can be maintained with the nominal thermal environment, thruster firings, and attitude changes.”

Additionally, non-nominal thruster firings and attitude changes could be employed to maintain thruster temperatures. But, should these thruster firings and attitude controls fail to maintain thruster temperature, the thruster could be declared failed.

If this were to happen, there would be no serious impact to the remainder of Atlantis’ mission and a Nominal End of Mission (NEOM) would be carried out thanks to the redundancy provided by other thrusters.

Therefore, since a loss of the L3D thruster would still result in a NEOM, the MER problem report indicates that any off-nominal thruster firing or orbiter attitude change to maintain thruster temperature would likely be declared unnecessary by the Flight Control team.

This thought of declaring specific action to maintain thruster temperature as unnecessary was confirmed by the MOD (Mission Operations Directorate) and PROP (Propellant) console in Mission Control in a FD-8 presentation by OMS/RCS – also available for download on L2.

“Recommendations: Place thruster in last priority after [ISS] flyaround and take no further actions since predictions are that L3D will remain above 47 deg F.”

However, “Due to analysis uncertainty, it is prudent to determine alternate attitude(s) that could be used if updated analysis predicts lower temps or if actual behavior varies from predicted”

However, a change to the nominal post-undock attitudes would mean an increase in potential MMOD (Micro-Meteoroid Orbiting Debris) risk.

According to the FD-8 OMS/RCS report, “Vehicle attitude changes to place L3D in warmer Environment [would result in] increased MMOD risk.”

The increased risk would translate to approximately 5%, from 1:379 to 1:361 – still well within the acceptable risk matrix for the SSP (Space Shuttle Program).

Furthermore, full data readings on the health of the L3D and other shutdown thrusters would be maintained through EOM (End of Mission) since the thruster’s instrumentation is not affected by the heater failure.

No related posts.

Atlantis Status:

Her final hours with the orbital outpost have earned praise from engineers, managers and astronauts alike, most of whom have moved away from the politically correct “it” to the traditionally correct “her” when speaking directly of the famous spacecraft.

While the current NASA administrator is himself a veteran shuttle Commander, his comment that people will have forgotten how humans used to travel into space in 10 years time appears to have no basis in reality, if the tributes for the orbiter’s swansong mission – which continue to flood in from public and officials alike – are anything to go by.

Ironically, STS-132 (swapped with Discovery) - and STS-129 - weren’t originally manifested to Atlantis, with the previous plan to retire – or at least mothball – the orbiter after STS-125′s visit to service the Hubble Space Telescope.

Another stay of execution remains on the cards via STS-135, although that mission – if approved – may be handed to Discovery (article next week).

General Bolden, at least, remains less than enthusiastic about any plan that does not end the Shuttle Program as soon as possible, as he continues to champion the deeply unpopular proposal outlined in President Obama’s FY2011 budget.

For her part, Atlantis remains unfazed by her fate, and continues to behave impeccably on orbit, with only a small number of minor issues charged against the vehicle at the Mission Evaluation Room (MER), highlighted by the snagged cable on the Orbiter Boom Sensor System (OBSS) Pan/Tilt Unit (PTU).

“As far as the current mission goes, there was a little bit of bad luck,” noted SSP (Space Shuttle Program) manager John Shannon on the Shuttle Standup/Integration report (L2) – in reviewing the first part of the mission. “It was just very strange how that cable got routed right between the connector and the little stanchion piece that kept it from tilting up on our inspection.”

STS-132 Specific Articles: http://www.nasaspaceflight.com/tag/sts-132/

While the unit is now able to translate through the required movements that will allow for the Laser Dynamic Range Imager (LDRI) to finally complete a full scan of Atlantis’ RCC panels, Mr Shannon praised the teams for utilizing a variety of assets to allow for the clearance of the vehicle’s Thermal Protection System (TPS) for entry.

“The team has done an amazing job of looking at options and alternative ways of getting inspection data. The RPM looked like it went really well. Overall, it looks like a really clean vehicle. There (were) really (no) reasons to suspect any damage to the vehicle. We will go do the risk trades to get as much inspection data as possible before undocking.”

Those discussions on whether to carry out a docked inspection during these late docked days on Station resulted in a decision to press ahead with a nominal Late Inspection plan – which will take place on Flight Day 11.

Although the discussions took several days to conclude, the process of clearing Atlantis from any TPS concerns was typically methodical, and carried out at a pace that ensured the Damage Assessment Team (DAT) presented their recommendations only when they were ready to do so.

All but one of the Atlantis’ array of thrusters will be available for undocking, following an issue with the L3D RCS (Reaction Control System) thruster’s heater shortly after entering orbit. However, concerns the thruster may start to leak – itself not a major impact – have been allayed by good temperature management whilst on orbit.

“All passive thermal temperatures are within acceptable range and all thermal systems are performing nominally except the L3D RCS thruster heater, which is failed off,” noted the MER (L2). “Current docked attitude is maintaining L3D temperatures within limits.

“No heater cycles have been observed on this thruster. The lowest injector temperatures observed during this shift were 71.7 deg F for fuel and 72.7 deg F for oxidizer.” A full overview of the L3D management plan for post docking will be published in the next article.

“25 of 38 primary thrusters have been fired. No new Primary thrusters were fired since previous report,” with all 38 thrusters set for a two pulse test on EOM-1 (End Of Mission minus one day) during pre-entry checkouts of Atlantis’ systems.

Atlantis’ three Auxiliary Power Units (APUs) and Fuel Cells all continue to show good health, bar a small issue with Fuel Cell 3 noted via its monitoring hardware - although the FC continues to operate nominally.

“All APU on-orbit parameters are nominal. All APU heaters are operating on the ‘A’ circuit. Subsystem performance is nominal. The PRSD (Power Reactant Storage and Distributation) O2/H2 manifold 2 isolation valves were cycled closed for crew sleep and reopened (prior to crew wake up).

“Fuel Cell 3, s/n 118, O2 flow meter indication continues to be erratic. It did indicate an increase in flow at the beginning of the fuel cell purge and a decrease at the end of the purge, verifying proper purge valve operation.”

According to the flight plan, the undocking late in the crew day will not allow for a water dump – as per usual – pending any change of plan by the Mission Management Team (MMT). However, Atlantis has enough spare capacity to allow the dump to occur on Flight Day 11 if required.

“Life Support Subsystem is operating nominal, working no issues. Total GN2 = 294.1 lbs. Total Supply water = 391.4 lbs (large transfer to ISS). Total waste water = 58.6 percent (100 lbs),” noted the MER’s most recent status report.

Nominal performance is mirrored throughout the system report, which has become the norm on most recent flights, though under appreciated given the complexity of the vehicle.

“A review of the GPS Data during this period confirmed that the GPS was operating nominally. The GPS team is not working on any issues or funnies,” added examples of the MER status overview. “The Flight Control System is operating nominally. All communications subsystems are performing well. The DPS (Data Processing System) HW (Hardware) team is not working any issues at this time.”

Atlantis is due to undock from the ISS at 10:22am Central Time, prior to a one lap flyaround of the Station, and the main separation burn at 12:05pm Central.

No related posts.

Atlantis Status:

As the crew proceed through Flight Day 5, the mission continues to track the pre-planned timeline, along with the benefit of additional time being released by the confirmation no Focused Inspection (FI) is required – based on the opening evaluations by the Damage Assessment Team (DAT).

“STS-132: On-Orbit: Flight Day 4 Activities Completed: EVA-1 by Reisman and Bowen to install the back-up Space-to-Ground antenna on the Z-1 truss and install a new tool platform on the Dextre Robot,” outlined the NASA Test Director (NTD) update (L2).

“Flight day 5 Activities Planned: Unberth Russian Rassvet module from Atlantis PLB (Payload Bay) and install on the Earth-Facing port of Zarya module. Canadarm Unberth OBSS (Orbiter Boom Sensor System) and hand-off to RMS (Remote Manipulator System). EVA 2 preps, procedure review and campout by Bowen and Good.

“Cryo Margins: (above 12+0+2) O2 limited 29 hours. Transfer Status – end of FD3 report: Middeck Resupply status 80 percent complete. Middeck Return status 21 percent complete. Overall: Ahead of schedule at 48 percent complete.”

The Mission Evaluation Room (MER) have only added a light bulb failure and laptop communication issues associated with the Wing Leading Edge Sensor data to their items of interest – which remains a very short list.

Atlantis herself remains in great condition, with no new issues of note referenced over the past 24 hours. A slight issue with Fuel Cell 3 has not been deemed a worthy addition to the MER “funny” list, with subsystem performance classed as nominal.

STS-132 Specific Articles: http://www.nasaspaceflight.com/tag/sts-132/

“The PRSD O2/H2 manifold 2 isolation valves were cycled closed for crew sleep at 136:23:06 GMT and reopened at 137:07:58 GMT. The second on-orbit purge was performed, beginning at 137/12:06 GMT. During the 45.5 hour purge interval the approximate performance decay was 0.2 Vdc for fuel cell 1, 0.2 Vdc for fuel cell 2, and 0.18 Vdc for fuel cell 3,” added a MER Shift Summary (L2).

“Fuel Cell 3, s/n 118, O2 flow meter indication continues to be erratic. Fuel Cell 3 alternate line temperature has had indications of some trickle flow down the alternate line during the periods when supply H2O tank A is near 100 percent quantity.”

SRMS EE Survey/Port Wing Clearance:

With extensive plans being drawn up for what is in fact a relatively simply EVA task to free a cable that is obstructing the movement of the OBSS PTU (Pan/Tilt Unit) – full outline article will be published ahead of EVA-2 – the MMT are also closing in on potentially scrubbing plans to use the SRMS EE (End Effector) camera to survey part of Atlantis’ Port Wing.

Both the OBSS and the Port Wing evaluations are related, following the PTU’s inability to position the LDRI (Laser Dynamic Range Imager) sensors into a correct alignment with a strip of the RCC (Reinforced Carbon Carbon) during Flight Day 2 inspections.

Managers immediately called on additional assets to acquire photography of the Port Wing, notably during Flight Day 3′s approach and RPM “underneath” the orbital outpost – with two additional ISS crewmembers armed with 800mm cameras. All of the additional imagery has since been downlinked to DAT engineers on the ground.

The only issue with the RPM imagery came via shadowing by Atlantis’ Payload Bay Doors, which obscured the light source (of the sun) on several Port Wing panels, reducing the quality and resolution of the photographs.

Several options were presented, such as taking images from the Cupola module – however, such viewpoints would limit imagery to just “zone five” of the Port Wing.

The main option continued to be the use of the camera on SRMS’ EE, which would provide all of the required imagery. A summary of the procedure shows an impact to the schedule of around 2-3 hours, had it of been added after the MRM-1 installation task.

However, the task on FD5 was postponed due to the late finish of EVA-1 and the concentration on ensuring the MRM-1 docking and installation tasks were carried out without any squeeze on the day’s timeline.

“Planning: EE Survey added to FD5 after MRM Docking. Assumption: EE Survey activity may begin after MRM hooks have closed (~final 1 hr 15 min of MRM activity – Robo 1.101). Survey must be performed in daylight,” noted on of several MMT presentations on the options (L2).

“Three options presented by OPO were assessed by PDRS to determine duration of inspections. OPO (Orbiter Project Office) Option 1 = Stbd RCC, Port RCC, and Port Chine – Estimated time for completion = 2:45. OPO Option 2 = Port RCC and Port Chine – Estimated time for completion = 2:32. OPO Option 3 = Port RCC – Estimated time for completion = 2:20.”

Interestingly, the need to carry out the survey later in the mission may not be required, thanks to the work of the spacewalkers on EVA-1, who provided all the required imagery from the missing coverage on the Port Wing.

“Additional hand held imagery from crew EVA obtained missing coverage associated with port side chine tiles – images reviewed and no issues identified – no additional imagery required,” noted a MER shift report on FD5′s morning update. “TPS plan is to officially clear everything at OPO/MMT.

“RCC: Additional hand held imagery from crew EVA obtained and reviewed: Port panels 1-8 curry zones 6 and 7 went to green (1″ hole criteria area). Imagery analysts will verify resolution. Port panel 1 curry zones 4 and 5 and panels 2-8 curry zone 5 went yellow. Imagery analyst will verify resolution in AM. RCC repair option timelines were discussed and OPO was compiling the inputs for discussion.”

At the time of publishing, the MMT had not decided to remove the option from the docked phase of the mission (will be updated if this changes), with the early Tuesday meetings noting evaluations were continuing on some of the Port RCC panels, although the Chine area had been cleared.

“During the EVA, Garrett took pictures of the PORT Chine. Those pictures cleared that area from further inspection requirements. Pictures of the Port RCC were unfortunately not of sufficient clarity to clear that area,” added the Integrated MMT notes for FD5, although it is understood DAT were close to being satisfied the RCC could be cleared later on Tuesday – as eluded to in the MER shift report.

In addition to the good news about the Port Wing, the opening DAT findings have only noted several areas of cosmetic damage and a few protruding gap fillers.

Nothing unusual has been noted in the FD2 and RPM imagery, although the extensive process of fully evaluating the imagery involves not only an opening look at all the areas of interest, but a peer review – which ensures no mistakes are made with clearing the orbiter’s heatshield for Entry.

Another survey will be carried out during the mission, called Late Inspections, carried out after undocking – although once the PTU on the OBSS has been freed from the cable obstruction, a nominal survey and clearance procedure will be on tap.

Notably, the advances made in reducing foam loss from the External Tanks (ETs) – the main cause of damage on the orbiter’s TPS – has resulted in a long line of ‘clean’ flights. The last notable damage suffered by an orbiter was during STS-118 with Endeavour, although the “gouge” was still cleared for Entry without the need for a repair.

MRM-1 Install:

The installation of the Russian module was completed during the first half of Flight Day 5 without issue, despite being a highly complex mix of robotics and communications challenges.

The SSRMS (Space Station Remote Manipulator System) grappled MRM-1 at 5:14 am Central, following the removal of the module from Atlantis Payload Bay via the SRMS (Shuttle Remote Manipulator System). By 5:36 am, Atlantis’ robotic arm released the module, successfully transferring it from one robotic arm to the other.

STS-132 Mission Specialists Garrett Reisman and Piers Sellers maneuvered the station’s arm to deliver the module to its new position on the Russian segment of the space station, an effort which aptly waited for an orbital sunrise to deliver “Rassvet” (“Dawn”) to its permanent home.

Mini Research Module 1 (MRM-1) was manufactured from the residual Dynamic Test Article of the Science Power Platform (SPP). MLM outfitting hardware is mounted externally on MRM1. 1400 kg of NASA cargo launches inside (6.0 m3 of usable on-orbit stowage volume).

STS-132′s tasks associated with this module marked a number of new operations for the shuttle, as outlined in-depth via Flight Readiness Review (FRR) presentations.

“MRM-1 module operations while in Shuttle: MRM-1 module activation in payload bay on FD1 immediately after Post Insertion. MRM-1 is powered by Orbiter via Remotely Operated Electrical Umbilical (ROEU) via PL PRI and CAB PL bus from FD1 to FD5: Provides MRM-1 power for computers, active cooling and Cabin Fan/Smoke Detectors,” noted FRR presentation overviews (L2).

“MRM-1 Command and Telemetry interface provided through Orbiter via Orbiter Interface Units (OIU) /Payload Signal Processor (PSP) and Payload (PL) MDMs. MCC-H (Houston) sends commands on behalf of MCC-M (Moscow) while MRM-1 is in payload bay.”

Following MRM-1′s removal from Atlantis’ Payload Bay via the SRMS (Shuttle Remote Manipulator System), and handoff to the SSRMS, the MRM-1′s Automated Docking System (ADS) was powered up. This occurred once the SSRMS had positioned MRM-1 in the ‘pre-docking’ position – 150cm from the docking interface.

“MRM-1 module operations while on SSRMS: MRM-1 repower on SSRMS will reactivate core systems. MRM-1 Automated Docking System (ADS) will be powered up and the docking probe deployed,” added the overview. “After final interface alignment at 90 cm of docking interface separation, MRM-1 will be translated for final installation.”

Following powerup of the ADS, the MRM-1 docking probe was extended and an internal MRM-1 docking camera was activated – all while the module was attached only to the SSRMS. Crewmembers inside the ISS performed final alignments of the MRM-1 at a distance of 90cm from the docking interface.

This docking procedure was a critical part of the operation, with the potential a serious problem would result in an EVA and the module returning to Atlantis’ Payload Bay.

“MRM-1 docking probe removal in the event of probe retraction failure: In the event MRM-1 cannot be installed and the docking probe cannot be sufficiently retracted, EVA removal of the docking system will be required to return the module to the payload bay,” noted the contingency overview in the FRR materials.

“This contingency case requires multiple failures in a specific and brief period of time; due to this very low likelihood of occurrence, the decision was to establish a contingency plan to determine feasibility of execution but not complete all programmatic analysis required for the activity.

“Plan to put 2 EV crewmembers in APFR/PFR (Foot Restraints) on the Shuttle sill and have SRMS present the module to them for removal of 17 bolts and disconnection (or sever) of three power/data cables. Necessary EVA tools flying on Progress 37 to allow for EVA removal of an MRM-1 docking probe that is failed in a deployed state.

“EV crew members trained on flight hardware (1 g) at RSC-E facility in Moscow. Preliminary PDRS, SSRMS and EVA procedures have been developed and will be submitted in real-time as required. This contingency plan entails open-work associated with hardware tie-down or disposal.”

However, all went to plan, with contact sensors indicating the correct position for installation, allowing the MRM-1 automated docking software to retract the docking probe, drawing the interfaces together, close hooks and handover electrical and data control of MRM1 to the FGB.

Additionally, MRM-1 was the first permanent ISS module to be installed via use of the Robotic Works Station (RWS) in the newly arrived Cupola viewing module – a module brought up to the ISS on the STS-130/20A mission in February of this year.

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Launch and Ascent Review:

“Taking the bird out of the barn for a few more trips around the planet,” Commander Kenn Ham thanked the Orbiter Project Office (OPO) for the late clearance of the final IPR (Interim Problem Report) that had threatened to be a constraint for coming out of the T-9 minute hold.

“During the closeout inspection prior to the final closing of the Payload Bay Doors (PLB) a ball bearing was found lying on a 1307 bulkhead blanket. The bearing was approximately 0.125 in. in diameter and weighed less than a tenth of a gram. No source was identified,” noted a Mission Evaluation Room (MER) outline on L2.

“Approximately 2 hr before launch, a pip pin used to hold one of 4 payload bay cameras to the shelf was identified as a possible source. There are 3 pins on each of the 2 aft cameras and 4 pins on each of the 2 forward cameras. A review of the failure history, installation verification, and design tolerances was performed to determine the likelihood of one of these pins losing a ball bearing.

“While the likelihood was determined to be very low, the team further evaluated the ability of the pin to engage its locking feature with one ball bearing missing. This analysis confirmed good locking function.”

With no other issues of note, Atlantis launched at the first attempt – marked at 134/18:20:08.991 GMT, with preliminary reports noting a flawless ascent, although there is an investigation of numerous “strange” observations from the SSME (Space Shuttle Main Engine) plumes during first stage – potentially caused by lighting conditions. Notably, the SSMEs performed without issue, as did all the propulsion systems.

“No problems or issues were noted during the ascent phase,” listed the official MER report. “The Reusable Solid Rocket Booster (RSRB) shutdown occurred at 134/18:22:09 GMT [00/00:02:06 Mission Elapsed Time (MET)] and the separation was visible.

“A nominal Orbital Maneuvering System (OMS) assist maneuver was performed following SRB separation. Ignition occurred at 134/18:22:24.3 GMT (00/00:02:16 MET, and the maneuver was 90.2 sec in duration. MECO occurred at 134/18:28:34 GMT (00/00:08:32 MET).

The ET separated from the Orbiter at 134/18:28:56 GMT (00/00:08:47 MET).”

Only one minor issue was recorded by MER during powered flight, which cleared prior to MECO (Main Engine Cut Off). Atlantis was successfully placed into her desired orbit, followed by the opening of the Payload Bay Doors and deployment of the Ku Band Antenna – which is working without issue.

“Thirty seconds prior to the launch, a Multifunction Display Unit (MDU) in Cathode Ray Tube (CRT) 1 slot reported a CRT 1 Built-In Test Equipment (BITE) Fail” with a detailed error of “Luminance Control Loop Fail”. The error cleared 7 min 51 sec later.

“The error repeated two additional times. Setting the brightness to the maximum condition can cause the error as backlight bulb luminance output reduces due to unit age. In this case, the error will clear once the MDU brightness is manually decreased by the user.

“A nominal OMS-2 maneuver was performed at 134/18:58:24.1 GMT (00/0038:16.2 MET). The maneuver was 63.0 sec in duration with a Differential Velocity of 96.5 ft/sec. The achieved orbit was 85.1 by 124.7 nmi. The payload bay doors were opened at 134/19:52:09 GMT (00/01:34:00 MET). The Ku- Band antenna was deployed and the self-test was completed with satisfactory results.”

STS-132 Specific Articles: http://www.nasaspaceflight.com/tag/sts-132/

ET-136 Performance:

Prior to the maneuver, hi resolution photography was taken of the jettisoned External Tank (ET-136), in order for imagery to be sent down to the ground to the Damage Assessment Team (DAT). Evaluations of the imagery allow for areas of foam loss to be potentially matched to debris events observed by several other ascent recording assets.

Photography from both the Umbilical Well camera located on the orbiter, and a handheld camera from the flight deck, captured the condition of the tank as it fell away from the orbiter, exposing the condition of its TPS foam.

Both sets of hi res photography was acquired by L2 on Sunday, showing the tank only lost foam from around two obvious areas to untrained eyes, while some other areas showed small signs of popcorning – which is completely normal.

One area of foam loss can be seen on the outside of one of the LH2 Ice Frost Ramps (IFR) and would be – even if it released in one piece – of a very small mass and thus no concern at all, even if it managed to impact the orbiter during the period of dangerous aerodynamic transport (prior to SRB sep).

A second area of liberation can be seen from the Z (top) side of the intertank, close to the left side bipod ramp, while the -Z (bottom) side appears to be mainly intact, bar some cosmetic pitting/popcorning – again usual.

Importantly, with only the single obvious area of intertank foam loss – should the positive observations be confirmed by experts – it would mark the second tank in row to prove the mitigation procedures that had been put into effect, following a number of flights that saw numerous losses from this area of the tank.

STS-131 flew with the first tank (ET-135) to fly with new production procedures at the Michoud Assembly Facility (MAF) – relating to the manufacture process prior to foam application – which eliminated the potential for dust to remain on the structure, reducing the adhesive properties and causing the foam to shed off during ascent.

With STS-132′s ET-136 also showing the benefits of the change, managers can be assured this issue has been solved, adding a further feather to their cap on what has been a very impressive long-term effort to reduce foam loss from the tanks since Return To Flight.

Flight Day 2 – OBSS:

The crew awoke on FD2 with only a printer issue to work through – as opposed to any problems with their multi-billion dollar orbiter – prior to getting into the main task of inspections via the use of the Orbiter Boom Sensor System (OBSS) boom, mated to the Shuttle arm.

“The SRMS On-Orbit Initialization was completed at 134/21:20 GMT [00/03:00 Mission Elapsed Time (MET)]. The SRMS power-on was completed at 134/21:42 GMT (00/03:22 MET). SRMS checkout was completed at 134/22:48 GMT (00/04:28 MET),” added another MER Status report (L2). After a brief survey of the payload bay, the SRMS was returned to the Pre-Cradle Position at 134/23:02 GMT (00/04:42 MET). All SRMS activities were nominal.

“The OMS-4 NC2 maneuver was a dual-engine straight-feed OMS firing that occurred at 135/11:33:02.7 GMT (00/17:12:53.7 MET). The firing time was 10.4 7 sec/7.9 ft/sec. The resulting orbit was 109.5 by 126.6 nmi. Engine performance was nominal.” NC-3 was also a nominal burn late in the flight day.

The survey of Atlantis’ RCC and upper level TPS proved to be troublesome, due to a cable catching and obstructing the range of the OBSS’ Laser Dynamic Range Imager (LDRI) attached to the Pan/Tilt Unit – notably with the tilt movement.

“The SRMS maneuver for OBSS grapple started at 135/11:48 GMT (00/17:28 MET), with grapple completed at 135/11:52 GMT (00/17:32 MET). The Starboard RCC survey began with the Flat Field Survey at 135/13:18 GMT (00/18:48 MET).  However, issues with the pan and tilt unit were interfering with the pointing of the camera,” noted MER information.

“OBSS SP1 cable snagged in hard stop prevented full PTU movement. Current planning in progress to perform an undocked IDC (Digital Camera) starboard and nose cap RCC inspection and a docked port EE RCC inspection. (Documentation) to approved the docked EE inspection.”

The reference to the docked EE inspection relates to the currently favored plan of finalizing missing coverage from the Port Wing survey by using the End Effector (EE) camera on the end of the SRMS to take high resolution imagery of the RCC.

Combined with data gained from the FD2 inspections, DAT engineers may also be aided by additional imagery taken from the ISS during Rendezvous.

Flight Day 3:

With no requirement for a Debris Avoidance Manuever (DAM) on the ISS – after a debris threat was tracked to the point it was confirmed it would not breach the 10km conjunction box – a nominal approach to the orbital outpost was conducted on Flight Day 3.

Closing in on the ISS via several burns – including the TI (Terminal Initiation) burn – Atlantis and her crew arrived below the ISS for the initiation of the R-bar Pitch Maneuver (RPM) – at around 8:26am Central time on Sunday morning.

The RPM – Rbar denoting along the radius vector of the ISS, downward – allows the ISS crew to perform a high resolution photo survey of the lower surface TPS tiles to screen for ascent debris damage.

The nine minute maneuver – which involves the orbiter being commanded through a 360 degree back-flip – was debuted on STS-114′s Return To Flight mission, following months of planning by shuttle experts at the Johnson Space Center (JSC) and has been hailed as one of the major steps forward in ensuring the health of an orbiter prior to clearance being given for re-entry.

Due to the issues with the FD2 inspections, the Mission Management Team (MMT) adopted a plan to add two additional ISS crewmembers – armed with an 800mm camera – to increase the amount of imagery taken of the orbiter, ensuring DAT engineers have as much data to hand as is possible.

Plans are also being worked to see if the STS-132 spacewalkers can add a task of manually freeing the obstructing cable from the PTU, as planning starts to pick up on a solution to the Late Inspections, after undocking. An overview of those plans has been acquired and will be written up in an upcoming article.

Atlantis docked with the ISS at 9:27am Central time, following a flawless approach.

Atlantis Status:

The MER aren’t working any issues with Atlantis’ primary systems, all of which have been showing nominal performance during this early phase of what may be her final time on orbit.

“All APU (Auxiliary Power Unit) ascent soakback and on-orbit parameters are nominal. All APU heaters are functioning nominally on the ‘A’ string.  APU 1,2,3 Fuel Pump Drain Line Pressure #1  were TMBU’d from 25 to 40 psia at 134/17:21:00 GMT, approximately an hour prior to APU ascent start, to preclude nuisance alarms,” noted a few highlights from the expansive shift reports (L2).

“The first on-orbit fuel cell purge was a manual purge beginning at 135:14:35 GMT. Cryo O2 Heater Current Sensor Check was performed at 135:14:25 GMT and results were nominal. The Fuel Cell Monitoring System (FCMS) Data Take was performed. Results were nominal, with no outliers. There is no longer any evidence of the pre-launch pin sharing observed on FC3 (Fuel Cell 3) pins 90 & 91.

“23 of 38 primary thrusters have been fired. All passive thermal temperatures are being maintained within acceptable limits. Time limits for inspection attitudes were requested and we provided a limit of 6 combined hours for the first two inspection attitudes (+YSI and +XSI), and nominal time for the third attitude (-YSI).”

As one engineer working on the mission noted after his shift – “it’s almost like Atlantis knows this is her swansong, and she doesn’t want her final mission to be blotted by IFAs (In Flight Anomalies).” Further updates have been acquired, and will be summarized in upcoming articles.

*Additional content, such as transcribed notes and discussion, along with free video of all key events and briefings from NASA TV, are available in the STS-132 Live Section, linked near the top of the article. All quotes and content used in this article can be found in full via the associated L2 STS-132 Special Section (MMT level coverage).

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STS-127 Latest:

No major issues are being worked with Endeavour, as she patiently remains attached to the International Space Station (ISS) during the docked phase of the mission. However, the Station had suffered from a problem with the Waste and Hygiene Compartment (WHC) in the Destiny module.

The toilet – which arrived with Endeavour on STS-126 – was out of action until the first half of Flight Day 6. The six station crew members are using the facilities in the Russian Zvezda module, while Endeavour’s crew use the shuttle facilities – the Waste Collection System (WCS) – until the toilet is back on line later today.

“ISS Waste & Hygiene Compartment (WHC) Anomaly: At GMT 200/14:14 the crew reported an error indication on the WHC control panel following an inadvertent dose pump activation. Control panel should have safed system after 8 sec and did not,” noted a Mission Management Team (MMT) overview of the problem (L2).

“MCC had the crew manually shut the pump off by turning the main switch on the control panel to Off then the rack power switch to Off.

“Team is investigating the dose pump failure to automatically deactivate. Potentially flooding the pump separator unit and COT with pre-treat & water. A similar issue occurred in the SM (ACY) during Exp 14 – required several days to recover (with hardware changeouts).

“Crew has been directed to that the ISS crew should use the SM (ACY) and Shuttle crew should use the Shuttle WCS. Shuttle WCS has approximately 4 days of capability before offload required.”

The offload of the Shuttle WCS would be carried out via a water dump. However, due to a contamination threat to the newly arrived JEM experiments – or more specifically potential corrosion issues with the attach points – Endeavour is not allowed to conduct a water dump until after undocking.

Thankfully, the facility will be working again by the end of Flight Day 6, as components are replaced during a scheduled three hour work period on Monday.

Otherwise the mission is proceeding right along the timeline, with good cryo margins noted on Endeavour, and half of the shuttle to station transfers now complete.

“Cryo Margins (above 16+0+2) O2 Limited: 1 day of SSPTS-off time available.1 day 21 hrs of SSPTS-on time available,” added the MMT overview. “Transfer Status: Transfer is going well with 47 percent complete (now over 50 percent). CWC Transfers: 3 CWC-I’s so far (123 lbm). N2 Transfer: 12 lbm thus far.”

TPS Clearance – ET-132 evaluations:

“The MMT cleared the TPS for deorbit, entry, and landing,” was the single line noted on the Mission Evaluation Room (MER) logs, following another fine effort from the DAT engineers – who are tasked with evaluating hundreds, if not thousands, of images from FD2′s OBSS (Orbiter Boom Sensor System) surveys and FD3′s RPM photography.

DAT’s findings show Endeavour is a very clean vehicle, bar the 16 areas of damage to her starboard chine – only one of which required further evaluation for clearance due to the depth of the damage. A full article will follow this week, based on the 10 stunning DAT presentations acquired by L2.

Further understanding of the liberation events during Endeavour’s ride to orbit will be gained via the cameras on the Solid Rocket Boosters (SRBs), which are now back in port, with footage being sent to engineers on Monday.

“Liberty Star, with the RH (Right Hand) SRB, and Freedom Star, with the LH (Left Hand) SRB docked Saturday,” noted processing information. “Open Assessment is scheduled to begin this morning (Monday).”

Although the Chine damage was not caused by the unusual liberation of foam from ET-131′s intertank, the next tank to fly – ET-132 – is undergoing pull tests, to check the adhesive properties of its intertank application. Further tests are scheduled at the Michoud Assembly Facility (MAF) on downstream tanks, if required.

“C Platform is retracted. E Platform was re-extended to allow plug pulls at initially 20 locations to start later today on ET-132,” added Monday processing for STS-128 (L2). “Chit will be taken to the Noon Board today.”

STS-128′s launch date is currently under evaluation, based on ET-132′s results, and a realignment of the flow timeline once Discovery has arrived in the Vehicle Assembly Building (VAB) for mating. It is likely Discovery will still launch in the second half of August.

“The following operations have been rescheduled to support inspections resulting from the STS-127 launch debris events: Rollover to VAB for integration is scheduled NET (No Earlier Than) July 23. Shuttle Interface Testing will pickup immediately following Orbiter/ET mate.

“The STS-128 Shuttle Final Countdown Phase Simulation for team certification – July 21. Payload transport to Pad-A July 23.”

Flight Day 5 Catch Up:

Flight Day 5 was one of the more “relaxed” days in the mission so far – despite the toilet trouble. The main focus of the day was the continued the handover of Endeavour’s elaborate payloads to the ISS, as managers aim to boost the logistical supplies on Station ahead of shuttle retirement, “currently” set for 2010.

The 2J/A package includes the Japanese Experiment Module – Exposed Facility (JEM-EF) and the Japanese Experiment Logistics Module – Exposed Section (ELM-ES) as well as the Integrated Cargo Carrier – Vertical Light Deployable (ICC-VLD).

It was the latter ICC-VLD that was pulled out of Endeavour’s Payload Bay on Flight Day 5 by her robotic arm, before being handed over to the SSRMS and stowed on the Payload Orbital Replacement Unit Accommodation (POA).

Attached to the ICC-VLD are six P6 truss batteries – which will be part of the P6 battery R&R activities during EVA 3 – a Linear Drive Unit, Pump Module #2, and a Space to Ground Antennae – all of which will be transferred to ESP-3 (External Stowage Platform-3) during the upcoming spacewalks.

The Japanese ELM-ES will be installed on to the JEM-EF during Flight Day 7, while the Station’s robotic arm removes the ICC-VLD from POA, before using the Mobile Transporter system to move different worksite.

Endeavour is also flying with DRAGONSAT (Dual RF Autonomous GPS On-Orbit Navigator Satellite), MAUI (Maui Analysis of Upper-Atmospheric Injections), ANDE-2 (Atmospheric Neutral Density Experiment-2), SEITE (Shuttle Engine Ion Turbulence Experiment), and SIMPLEX (Shuttle Ionospheric Modification with Pulsed Local Exhaust).

EVA-2:

Wolf and Marshburn’s EVA-2 conducted the transfer of critical station spare components from ICC-VLD to External Stowage Platform-3, on an EVA that lasted 6 hours and 53 minutes.

“SSRMS ICC GRAPPLED: Prior to the start of the EVA, the SSRMS will grapple the ICC, which has been hanging out on the SRMS overnight on FN05,” noted the Flight Plan Walkthrough overview of EVA-2.

“The SRMS will ungrapple and the SSRMS will install the ICC on the POA. The SRMS will then maneuver to an EVA 2 viewing position. Lastly, the SSRMS releases from the ICC.”

“ICC ORU (Orbital Replacement Units) Transfers: The EV crew will translate to the ICC and transfer 3 ORUs (SGANT – Space to Ground Antenna, PM – Pump Module, LDU – Linear Drive Unit) from the ICC to ESP3.

“EV1 will use the APFR (Foot Restraint) during the translation and installation of the ORUs and will egress the APFR at the end of the task.”

As hoped, the communication issues did not interfere during EVA-2, following noisy audio issues during the opening spacewalk. The MMT noted that the problem was related to a poor placement of the microphone inside Tim Kopra’s helmet.

“EVA1 Noisy Audio from EV2 Comm Cap (AR 4081): Suspected issue with microphone placement – noise level changed during EVA when EV2 tried to adjust microphones. This comm cap is not planned for use again. No further troubleshooting is planned.”

For live coverage, refer to the live update pages linked above.

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.

Related posts:

1. Endeavour and her SCA piggyback ride arrive in Louisiana, via JSC flyover The Shuttle Carrier Aircraft (SCA) and Endeavour departed from Edwards...

Flight Day 9:

Heading towards the final leg of the mission, Atlantis and her crew have a busy FD9, which opened with the charging of the Hubble’s batteries – required early in the day in order to allow the opportunity for backup daylight pass.

The SRMS (Shuttle Remote Manipulator System) then grappled the telescope while its umbilicals were disconnected.

While Atlantis maneuvered to the HST release attitude ahead of HST deployment, Mike Massimino and Mike good carried out a full EVA prep – up to the point of donning their EMU suits – in the event of being required to manually troubleshoot an issue with the release.

After a successful release – pre-empted by the opening of Hubble’s Aperture Door and the SRMS release – Atlantis performed two burns to place the orbiter in a safe relative motion separation from HST, before performing an Orbit Adjust burn to lower one side of the orbit, thereby removing herself partially from the high debris field for around half of her resulting elliptical orbit.

Following the stowage of the Flight Support Structure (FSS), Atlantis’ OBSS (Orbiter Boom Sensor System) is unberthed for Late Inspections (LI).

Late Inspections – 11R interest:

Following on from Flight Day 2′s inspections, another overview of Atlantis’ Thermal Protection System (TPS) was conducted later in the flight day. However, only critical surfaces – such as the Wing Leading Edge (WLE) Reinforced Carbon Carbon (RCC) panels – were re-inspected.

“Only the WLE RCC and Nose cap inspections are repeated from FD2. New for STS-125 only, daylight requirements for Zones 1-4 of Panels 8 thru 11 for both Port and Starboard surveys.

“The intent is to take credit for ISIS Digital Camera (IDC) in order to reduce MMOD (Micro-Meteoroid Orbital Debris) risk numbers,” noted one overview presentation (L2).

“These particular panels are of importance to determine minimum diameter impacts. A portion of the Port Zone 1-4, Panel 8-11 scan has a poor IDC angle. Therefore, a dedicated repeat of that portion (about 30 minutes) will be performed.

“The attitude and pointing constraints are the same as for the FD2 inspections.”

MMOD strikes since Flight Day 2′s inspections are the only real threat to the orbiter’s TPS, with the increased risk well known ahead of Atlantis’ flight to Hubble, which is in a higher – more debris potential – orbit than the regular trip to the International Space Station (ISS), which also provides a level of protection to a docked orbiter.

Thanks to the WLE IDS (Impact Detection System), Atlantis can “feel” the slightest impact to her RCC panels during the mission, and it was one small “trigger” on Panel R11 that has attracted the attentions of the Mission Management Team (MMT).

“Potential MMOD Damage on Panel 11R: Provide a description of the expected damage on Panel 11R if the 0.47G WLEIDS indication was due to an MMOD impact,” listed one expansive presentation created by the Orbiter Project Office (OPO) and available on L2.

The registering of a 0.47 Grms trigger wouldn’t normally be of any concern, with recent ISS flights registering ‘impacts’ of up to 2.5 Grms – and 10.0+ Grms usually classed as the point where damage becomes a concern.

However, several factors have to be taken into account, such as the make-up of the debris that impacts, the angle, its mass, the health of the WLE IDS sensors, and the orbiter’s attitude at the time. These factors have raised the level of interest in the 11R event.

“Given the attitude and assuming an orbital debris strike on 11R, damage is more likely on the lower surface than upper,” added the presentation. “Cannot preclude orbital debris or micrometeoroid impacts to the upper or apex surfaces. O1 indication at GMT 132:20:00:18. Attitude was PYR: R40.18, P21.29, Y40.14.”

Managers are not concerned that the impact – if confirmed to be an impact in the first place – will have breached the level of acceptable damage. Coating damage, pits and even small holes would not prove to be a safety issue on re-entry. For context, the damage to Columbia on her ill-fated STS-107 mission resulted in almost a full panel missing, as opposed to the worst case scenario of a microscopic pinhole for Atlantis.

“For Panel 11R, the expected damage is coating damage with limited exposed substrate which would not exceed the damage criteria for Panel 11R (0.16 in. dia.),” added the presentation. “High confidence in detecting critical damage on Panel 11 with LDRI (Laser Dynamic Range Imager). IDC (Digital Camera) imagery on STBD lower surface will also be available.”

Backing up their findings, testing was conducted at the White Sands Test Facility (WSTF), in an attempt to reproduce how the RCC panel coped with a similar impact that potentially occurred on Atlantis.

“Evaluate WSTF Hypervelocity Impact Test Data on Panel 16R (Test Article). Test consisted of 20 impacts on an RCC panel with accelerometers on the spar. Damages ranged from SiC only damage to through penetrations. Data cannot be used directly due differences in boundary conditions between the vehicle and test,” noted the test results.

It is highly likely that any potential damage will not be anywhere near enough to threaten the requirement of launching Endeavour – currently sat on Pad 39B as the STS-400 LON (Launch On Need) shuttle, and ready to enter her launch countdown on Wednesday if required.

Even if the damage was unacceptable for re-entry, an EVA repair would likely be the first option available to the crew.

“STS-400 Late LON S0007 Launch Countdown: CTS (Call To Stations) is scheduled for 0530L tomorrow morning,” noted Tuesday processing information (L2) on the status of STS-400 readiness. “FD9 Late Inspection will drive MMT Go/No-Go direction for PRSD (Power Reactant Storage and Distributation) load.

“A go for PRSD load will indicate possible concern in the TPS Late Inspection. A No-Go decision will result in a 24-hour hold in S0007, and the launch team will remain in a LON posture until completion of the de-orbit burn.

“If landing is waived off on Friday, the 24-hour holds will continue until the de-orbit burn has been completed. S0024 Hyper QD (Quick Disconnects) de-mates will be performed in S0007 post-PRSD load.”

STS-125 Landing:

Related to both Friday’s targeted return of Atlantis and Flight Day 10′s well earned off duty time for the crew, the MMT evaluated the issuing a waiver to enable a landing on orbit rev earlier than scheduled. The waiver would allow for the resulting violation in the Shuttle Crew Scheduling Constraints (SCSC).

“Potential Crew Time Off SCSC violation: Rule 2.6.1.3 Crew Off Duty Time requires six hours crew off duty time for this mission duration,” noted last night’s MMT meeting documentation (L2). “If agreement is reached to target KSC landing one rev earlier on EOM (End Of Mission), it will incur an SCSC violation. Crew will lose 1-1.5 hours of required crew off duty time to accommodate the required sleep shifting.

“Rationale for requesting the earlier landing opportunity: Increased propellant margin. Provide a landing opportunity prior to expected KSC sea breeze setting up. Provides 3 deorbit opportunities at KSC EOM +1. Crew was informed about the request last night and will provide their recommendation.

“Request approval of MMT to waive the SCSC constraint in the event crew agrees to the sleep shift plan.”

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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Atlantis Latest:

No major issues are in work, as Atlantis continues to perform well on orbit. However, several pre-emptive actions have been taken by the Mission Management Team (MMT), including what is now over 20 presentations (available on L2) on the ASA channel 1 failure during last week’s ascent – which will be rounded up in Tuesday’s article.

“The MMT continues to meet daily with no significant issues being worked; the mission continues to proceed as scheduled,” noted MMT latest (L2) on Flight Day 8, adding two items of interest to the Mission Evaluation Room (MER) list.

“Humidity Separator B water carryover: The crew reported seeing water on the Humidity Separator B area in the ECLSS (Environmental Control and Life Support System) bay under the Middeck floor during the standard Hum Sep inspections.”

This is not a significant issue and has been seen on previous missions. Engineers note it is likely caused by “water carryover in the air outlet.”

“Water was wiped off and Hum Sep A was powered up to increase the separation rate. Currently on A & B,” added the MER report. “Plan is to power down Hum Sep B during pre-sleep after inspection for water.”

Another new item of interest relates to Atlantis’ Fuel Cell 1′s voltage readings. While the issue also holds no mission impact, it will continue to be monitored by controllers on the ground.

“A Fuel Cell 1 sub-stack 1 delta voltage increase trend has been seen since the first manual purge. At 132/20:37 GMT (01/02:36 MET) when the crew initiated the purge on Fuel Cell 1, sub-stack 1 delta voltage reading increased by 12 mV (mill volts),” noted the MER report.

“During the fuel cell auto purge on Flight Day 4 at 134/21:53:55 GMT (03/03:52 MET), the reading increased by 20 mV. During the last fuel cell auto purge on Flight Day 6, at 136/22:14:55 GMT (05/04:13 MET) the reading increased again, this time by 26 mV.

“After each increase the reading decreased slightly but not back to where it was before the purge. The total sub-stack 1 delta reading is at 32 mV, a total increase of 26 mV from its prelaunch baseline value of 6 mV. Flight rules drive a bus tie when the delta reading is above 50 mV the prelaunch baseline. The team continues to monitor.”

Other issues have been ably dealt with by Atlantis and her crew, such as the core dump of the Flash Evaporator System (FES), required after icing in the system.

“A Flash Evaporator System (FES) water dump was initiated on the FES Primary A Controller at approximately 136/10:46 GMT [04/16:44 Mission Elapsed Time (MET)] for 10 hours,” added MER. “It was successfully completed at approximately 136/23:38 GMT (05/05:36 MET).”

FD8/EVA-5:

Flight Day 8′s focus was on the fifth EVA of the mission, conducted by Grunsfeld (EV1) and Feustel (EV2). Their tasks included the changeout of Bay 3′s battery, the replacement of the Fine Guidance Sensor-2 replacement, and the installation of a New Outer Layer Blanket replacement over Bay 5 – all of which have been completed.

Thanks to being one hour ahead of the timeline after the FGS-2 replacement task, controllers on the ground added the deleted tasks from EVA-4, allowing EVA-5 to install the remaining NOLB thermal blankets on Bay’s 7 and 8 – thus completing all the tasks designated to STS-125′s work on Hubble.

“EV2 retrieves the new Bay 3 Battery from the SLIC (Super Lightweight Interchangeable Carrier). On MCC Go, EV1, at the Bay 2 location, removes the old battery. The two EV crew swap batteries. EV1 installs the new battery, while EV2 translates over to the SLIC to stow the old battery on the SLIC for return. The ground will perform an aliveness test followed by a functional test,” outlined the Flight Plan walkthrough.

“FGS-2 R&R: The new FGS is removed from the ORUC (Orbital Replacement Unit Carrier) using the EVA handhold that is permanently installed on the FGS prior to launch. This handhold will remain in place. The FGS changeout begins by MS2 deploying the aft fixture. EV1 opens the

“FGS-2 Doors, which are at +V3. After MCC-Go, the crew demates FGS-2 connectors. Using a portable handhold, which EV1 installs onto FGS-2, he removes FGS-2 and temp stows on aft fixture. EV1 (RMS) and EV2 (FF) head over to the FSIPE to retrieve the new FGS-2. They head back to the +V3 FGS bay 2, where EV1 installs the new FGS-2. The crew then close the FGS-2 bay doors and translate to FSIPE to stow the old FGS-2.

“The ground will then perform an aliveness test,” which has been successfully conducted.

“NOBL 5 Install: The crew retrieves the bay 5 MLI recovery bag from the ORUC. EV2 retrieves the NOBL5 from the MULE (Multi-Use Lightweight Equipment). EV1 removes the MLI and stows for return. He then receives the NOBL5 from EV2 and installs it.”

This has also been completed in good time, allowing for the final two NOBLs to be installed, deferred from EVA-4, due to the issues with the removal of a handrail from the Space Telescope Imaging Spectrograph (STIS) repair task, which resulted in spacewalker Mike Massimino literally ripping off the handrail from the fourth and final bolt fastener that refused to release.

“Space Telescope Imaging Spectrograph (STIS) Repair – difficulty removing the EVA handrail due to the lower right fastener being stripped,” noted the MMT overview of the issue. “Crew manually broke the fastener to enable removal.”

Most importantly, the management of the five EVAs has ensured all tasks, some of which were not required for minimal mission success, have been conducted on the telescope.

“That’s it, you guys have done it all,” noted MCC-H to the STS-125 crew as the final NOBL was being installed. “You hear that, we’ve done it all!” came back the call from the crew.

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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EVA-4:

With the highly successful EVA-3 behind them – and only two EVAs to go – astronauts Massimino and Good ventured outside of shuttle Atlantis to undertake the forth spacewalk of the mission.

The first item on the list for EVA-4 was the repair of the Space Telescope Imaging Spectrograph (STIS), with the second task - the installation of the New Outer Blanket Layer (NOBL) 8 – due to follow on the schedule, before being deleted due to timeline constraints.

Given the expediency of Saturday’s Advanced Camera for Surveys (ACS) repair – a repair effort that saw John Grunsfeld and Drew Feustel not only finish the timelined repairs of ACS but also complete several get ahead repairs of ACS – Massimino and Good were tasked with another complex spacewalk.

First installed on February 14, 1997 during the STS-82 SM-2 (Servicing Mission 2) mission of shuttle Discovery as a replacement for the Goddard High Resolution Spectrograph, STIS stopped working on August 3, 2004, two years after its expected end-of-life service.

The instrument was placed into a “safe” mode, pending EVA-4′s repair.

During its operations, STIS provided scientists with spectra and images at ultraviolet and visible wavelengths, and conducted the first spectrum analysis of the atmosphere of an extra-solar planet.

Due to an issue with a troublesome bolt on the STIS handrail, a plan was created for its removal, which resulted in Massimino being instructed to snap the handrail off.

This plan – simulated by engineers at the Goddard Space Flight Center as the plan was being created – called for 60 lbs of pressure on to the handrail to snap it off. This was a potentially dangerous operation on orbit, as the force will be translated through to Massimino, and debris risks were threatened via the unorthodox removal.

However, the plan worked, with no debris of note liberating from the hardware, and all 111 fasteners were successfully removed, freeing the electronics box for its repair to take place.

Due to the task taking over two hours longer than expected, the installation of NOBL 8 – designed to help maintain thermal conditioning of the telescope – was deleted from EVA-4. The spacewalk ended after eight hours and two minutes, the six longest EVA in history.

Following these activities, Hubble was rotated to the +V3 forward position in preparation for the fifth and final EVA dedicated to servicing of the telescope.

The EVA – as with all flight days – was covered live on the LIVE UPDATE pages – link above.

TPS Assessments:

Following a spectacular launch on Monday afternoon, Atlantis’ Flight Crew went right to work inspecting their vehicle for any damage incurred during liftoff.

During the early hours of FD-1 (Flight Day 1), the crew used the End Effector (EE) camera on the Shuttle Remote Manipulator System (SRMS) to observe the upper surfaces of the crew cabin – one of the survey techniques added to the STS-125 timeline due to the lack of R-bar Pitch Maneuver photography from the International Space Station crew.

A report from the Mission Management Team (MMT) on FD-2 confirmed that this inspection was complete, stating “upper canopy inspections complete. No damage failing criteria was identified.”

Thus, the DAT was able to clear this portion of Atlantis’ TPS (Thermal Protection System) for reentry while the crew performed the standard FD-2 inspections with the OBSS (Orbiter Boom Sensor System).

Also noted by the MMT report on FD-2 was a clean T-0 umbilical area on Atlantis, no obvious damage to the lower TPS acreage (another inspection technique added to STS-125 from nominal Space Station missions), and a damaged area of chine tiles.

The area of chine damage was most likely caused from an impact by a piece of liberated Ice Frost Ramp foam from the External Tank (ET-130) during launch, an impact which was recorded by the Wing Leading Edge sensors 106-seconds after liftoff.

A FD-3 TPS DAT summary presentation – available on L2 – noted that the OBSS inspections showed that the largest area of chine damage was 2.64” x 1.2” with an imagery uncertainty of +/-0.25”. Initial estimates place the angle of ET foam impact on the chine tiles at <10-degress.

Nevertheless, while all the chine area damage sites are within acceptable margins for a safe performance of the damaged tiles during reentry, the DAT requested an analysis of the interaction effects of the damage sites.

This assessment was called for due to the close proximity of the damage sites and their potential effects on heating increases to downstream chine damage sites from upstream chine damage sites, heating increases on the RTV bond line interfaces, and structural temperatures/margins.

For a better understanding of the region in question, the DAT summary included information on the underlying structures near the chine damage locations.

“Damage sites are located in close proximity to structural splice between honeycomb leading edge panel and lower skin panel,” notes the DAT presentation.

The area underneath the TPS chine also includes an internal rib structure with upper and lower caps and vertical posts at the leading edge and “thinwalled aluminum tubes.”

“Upper and lower skins are ‘skin/stringer’ configuration. Stringers run in the forward and aft direction.”

The first analysis conducted at the request of the DAT was a test of the downstream heating effects of upstream damage sites.

For this analysis, engineers examined chine damage site -002 (the forward most significant damage site) and its effect on downstream, adjacent damage site -001.

Engineers, using wind tunnel testing, determined that downstream “heating from -002 will have decayed by 85 percent” by the time it travels 0.66” – the distance between chine damage sites -002 and -001.

Furthermore, the damage cavity interaction analysis yielded positive results for reentry.

“Aeroheating team assessed impacts of the -002 damage site and the transition time and bump factors for the -001 damage site,” notes the DAT summary. “Size of the -002 damage site was not large enough to impact transition time.”

Nevertheless, the DAT noted that some minor influences could occur to bump factors downstream of -002 during reentry. However, these influences would be of no concern for crew or vehicle safety.

Additionally, the assessment team also analyzed the impacts to the RTV bond line margins due to the chine TPS damage.

Again, this analysis yielded positive results for reentry, with the most badly damaged tile maintaining a safety margin of +1.75. Similarly, the impacts on the structural margins of Atlantis are well within the design limits of the vehicle.

The analysis team, using a conservative dataset (assumed a 25 percent greater impact angle than that observed on orbit), determined that the maximum structural temperature Atlantis will experience due to the damaged chine tiles would be 190 degrees F – well below the 350 degrees F maximum temperature limit.

As such, structural integrity of the vehicle has not been compromised in any way because of the chine damage.

Furthermore, the DAT also relied on past flight experience and flight history with underbelly and chine tile damage.

As was seen during the analysis of the tile damage on STS-118 in August 2007, engineers poured through the vast flight history of Shuttle TPS damage to determine what ground crews can expect once Atlantis’ returns home.

Past examples of significant chine damage occurred on STS-41G, STS-27, STS-73, and STS-87 – with the worst such damage being Challenger’s STS-41G mission.

On that particular flight, the damage area extended for eight TPS tiles and had a maximum depth of 1.5”. Challenger returned without incident and the effected tiles were replaced during the vehicle’s turnaround processing flow.

Finally, further analysis of the imagery obtained during the FD-2 inspections showed that all damage sites identified passed the inspection criteria agreed upon before the mission.

No lower surface protrusions were observed, the ET doors were verified closed with positive seal margins, no protruding gap fillers or lifted blankets were observed on the OMS pods, and the upper LESS carrier panel was verified to have all its tiles in place.

As was noted prior to the mission, the base heat shield around the main engines and OMS pods was not imaged due to length limitations of the OBSS.

The inability to image this area of the vehicle was accepted during pre-flight meetings and reviews mainly due to the fact that the base heat shield experiences higher temperatures during ascent than it does during reentry.

Furthermore, with the pick-up inspections of a 40-tile region missed during the FD-2 inspections, the DAT team has officially cleared Atlantis’ TPS for reentry.

Atlantis’ crew will re-inspect the vehicle’s Wing Leading Edge and Nose Cap RCC panels on FD-9 to ensure that no damage occurred after their initial inspections.

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:

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