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While Atlantis maneuvered to the HST release attitude ahead of HST deployment, Mike Massimino and Mike good carried out a full EVA prep \u2013 up to the point of donning their EMU suits \u2013 in the event of being required to manually troubleshoot an issue with the release.<\/p>\n
After a successful release \u2013 pre-empted by the opening of Hubble\u2019s Aperture Door and the SRMS release \u2013 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.<\/p>\n
Following the stowage of the Flight Support Structure (FSS), Atlantis\u2019 OBSS (Orbiter Boom Sensor System) is unberthed for Late Inspections (LI).<\/p>\n
Late Inspections \u2013 11R interest:<\/p>\n
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Following on from Flight Day 2\u2019s inspections, another overview of Atlantis\u2019 Thermal Protection System (TPS) was conducted later in the flight day. However, only critical surfaces \u2013 such as the Wing Leading Edge (WLE) Reinforced Carbon Carbon (RCC) panels \u2013 were re-inspected.<\/p>\n
![\"a131\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2009\/05\/a131.jpg\" "\\"a131\\"")
\u201cOnly 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.<\/p>\n\u201cThe intent is to take credit for ISIS Digital Camera (IDC) in order to reduce MMOD (Micro-Meteoroid Orbital Debris) risk numbers,\u201d noted one overview presentation (L2).<\/p>\n
\u201cThese 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.<\/p>\n
\u201cThe attitude and pointing constraints are the same as for the FD2 inspections.\u201d<\/p>\n
MMOD strikes since Flight Day 2\u2019s inspections are the only real threat to the orbiter\u2019s TPS, with the increased risk well known ahead of Atlantis\u2019 flight to Hubble, which is in a higher \u2013 more debris potential \u2013 orbit than the regular trip to the International Space Station (ISS), which also provides a level of protection to a docked orbiter.<\/p>\n
![\"a121\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2009\/05\/a121.jpg\" "\\"a121\\"")
Thanks to the WLE IDS (Impact Detection System), Atlantis can \u201cfeel\u201d the slightest impact to her RCC panels during the mission, and it was one small \u201ctrigger\u201d on Panel R11 that has attracted the attentions of the Mission Management Team (MMT).<\/p>\n\u201cPotential 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,\u201d listed one expansive presentation created by the Orbiter Project Office (OPO) and available on L2.<\/p>\n
The registering of a 0.47 Grms trigger wouldn\u2019t normally be of any concern, with recent ISS flights registering \u2018impacts\u2019 of up to 2.5 Grms \u2013 and 10.0+ Grms usually classed as the point where damage becomes a concern.<\/p>\n
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\u2019s attitude at the time. These factors have raised the level of interest in the 11R event.<\/p>\n
\u201cGiven the attitude and assuming an orbital debris strike on 11R, damage is more likely on the lower surface than upper,\u201d added the presentation. \u201cCannot 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.\u201d<\/p>\n
Managers are not concerned that the impact \u2013 if confirmed to be an impact in the first place \u2013 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.<\/p>\n
\u201cFor 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.),\u201d added the presentation. \u201cHigh 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.\u201d<\/p>\n
![\"a141\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2009\/05\/a141.jpg\" "\\"a141\\"")
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.<\/p>\n\u201cEvaluate 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,\u201d noted the test results.<\/p>\n
It is highly likely that any potential damage will not be anywhere near enough to threaten the requirement of launching Endeavour \u2013 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.<\/p>\n
Even if the damage was unacceptable for re-entry, an EVA repair would likely be the first option available to the crew.<\/p>\n
\u201cSTS-400 Late LON S0007 Launch Countdown: CTS (Call To Stations) is scheduled for 0530L tomorrow morning,\u201d noted Tuesday processing information (L2) on the status of STS-400 readiness. \u201cFD9 Late Inspection will drive MMT Go\/No-Go direction for PRSD (Power Reactant Storage and Distributation) load.<\/p>\n
\u201cA 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.<\/p>\n
\u201cIf 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.\u201d<\/p>\n
STS-125 Landing:<\/p>\n
Related to both Friday\u2019s targeted return of Atlantis and Flight Day 10\u2019s 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).<\/p>\n
\u201cPotential 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,\u201d noted last night\u2019s MMT meeting documentation (L2). \u201cIf 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.<\/p>\n
\u201cRationale 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.<\/p>\n
\u201cRequest approval of MMT to waive the SCSC constraint in the event crew agrees to the sleep shift plan.\u201d<\/p>\n
L2 members<\/em><\/em>: Documentation \u2013 from which most of the above article has quoted snippets \u2013 is available in full in the related L2 sections, now over 4000 gbs in size<\/em><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"
The last humans to visit the Hubble Space Telescope have departed, leaving behind a rejuvenated spacecraft that will keep astronomers happy well into the next decade. Atlantis\u2019 highly successful mission has completed Flight Day 9, which included Late Inspections \u2013 with one RCC panel (11R) deemed to be of increased interest due to a potential […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[9197,8290,7935],"class_list":["post-41098","post","type-post","status-publish","format-standard","hentry","category-news","tag-mmt","tag-sts-125","tag-tps"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/41098"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=41098"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/41098\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=41098"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=41098"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=41098"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}