![\"A2\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2009\/09\/A2.jpg\" "\\"A2\\"")
The ATA was then installed onto the P1 truss well ahead of schedule, thanks to the smooth transition through the tasks.<\/p>\nSTS-128 has successfully completed the second of three spacewalks, which focused on the replacement of an Ammonia Tank on the International Space Station (ISS). Meanwhile the Damage Assessment Team (DAT) have given an expansive roundup of their rationale to clear Discovery for entry, which was approved by the Mission Management Team (MMT).<\/p>\n
EVA-2:<\/p>\n
The second EVA (Spacewalk) for Discovery\u2019s mission \u2014 and the 132nd EVA dedicated to construction and outfitting of the International Space Station \u2014 involves astronauts Danny Olivas and Christer Fuglesang of the European Space Agency (ESA) installing a new Ammonia Tank Assembly (ATA) to the P1 truss of the International Space Station (ISS).<\/p>\n
With a delayed egress from the Station\u2019s Quest Airlock \u2013 due to the requirement to break Olivas\u2019 configuration to replace a chin strap \u2013 the duo first \u201cprepositioned\u201d a bag for EVA-3 to the outside of the ISS before translating to Discovery\u2019s Payload Bay where they removed the new ATA from the Lightweight Multipurpose Carrier.<\/p>\n
The ATA was then installed onto the P1 truss well ahead of schedule, thanks to the smooth transition through the tasks.<\/p>\n
Ammonia and Nitrogen coolant lines were then be attached to the new ATA, completing the first half of the EVA around 50 minutes ahead of the pre-planned schedule.<\/p>\n
Olivas and Fuglesang then translated back to Discovery\u2019s Payload where they berthed the spent ATA tank (which was removed during EVA-1) to the Lightweight Multipurpose Carrier for return to Earth.<\/p>\n
Due to the advanced made on the timline, a couple of get-ahead tasks were completed \u2013 including protective covers and foot restraints \u2013 prior to Fuglesang and Olivas translating back to the Quest Airlock and ingress the Station.<\/p>\n
Aerospace & Defense (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n Following EVA-1 on Tuesday, Mission Controllers compiled an \u201citems of interest\u201d list. The listed included the failed CO2 sensor in Nicole Stott\u2019s suit, the MMOD (Micro Meteoroid Orbital Debris) strikes on the Starboard Z1 truss toolbox, the loss of the TDRS 275 (Tracking and Data Relay Satellite 275) signal because of rain at the communications station in Guam, and fraying on Danny Olivas\u2019 gloves.<\/p>\n This fraying, while not a preexisting condition, is understood and the gloves have been cleared for use on the remainder of the mission\u2019s EVAs via a Mission Management Team discussion on FD-6 (Flight Day 6).<\/p>\n Furthermore, all metabolic rates for Nicole Stott and Danny Olivas were normal and the CO2 removal hardware in the spacesuits performed as expected.<\/p>\n Discovery Status:<\/p>\n Overall, Discovery continues to enjoy a relatively issue free mission at the ISS.<\/p>\n Current cryo margins (propellant margins) show that Mission Controllers and Discovery\u2019s crew have 2-days and 11-minutes of additional cryo above the 13+1+2 day baseline with the SSPTS (Station to Shuttle Power Transfer System) and 1-day 4-hours of additional cryo without SSPTS.<\/p>\n<\/p>\n Furthermore, the Mission Evaluation Room (MER) is tracking no new significant In-Flight Anomalies and only three new \u201cfunnies\u201d \u2014 which are not a constraint to the continuation of Discovery\u2019s mission.<\/p>\n The new funnies listed in the latest status report include the MADS Left OMS Pod Temperature OSH observed during ascent, an Uncalibrated MADS Left Wing Spar Web Measurement, and a KOH drop in Fuel Cell #2 (FC-2).<\/p>\n The only new \u201cfunny\u201d to receive more than a one line treatment in the status report was the Fuel Cell KOH level.<\/p>\n \u201cFC-2 Transient KOH level Dropped Below 29 percent,\u201d notes the report. \u201cSeveral transient drops seen during data review.\u201d<\/p>\n The current Flight Rule protects for a 24 percent KOH limit with a 5 percent margin of error for possible instrumentation problems.<\/p>\n Furthermore, engineers on the ground continue to evaluate the VRCS (Vernier Reaction Control System) following the system\u2019s deactivation on FD-2.<\/p>\n \u201cThe team continues to review the history of testing and understanding changes proposed to SODB\/FR and will provide a CHIT to document the use of the VRCS only as a contingency with risk associated to repressing manifold 5,\u201d added the Mission Management Team meeting minutes on L2.<\/p>\n Currently, it is believed that the temperature in manifold 5 reached -35 degrees F. This low temperature has given engineers concern that the oxidizer might have frozen.<\/p>\n As such, the engineering team is reviewing the possibility of a \u201cstaged repress procedure that the Mission Operations Directorate (MOD) has in draft form as a means to recover the F5R Vernier thruster if a contingency requires.\u201d<\/p>\n DAT\u2019s TPS Evaluations:<\/p>\n As reported on Wednesday, five days of extensive review led to the Damage Assessment Team (DAT) officially clearing Discovery\u2019s Thermal Protection System (TPS) for reentry. Their findings have been presented in a series of presentations to the MMT \u2013 all available on L2.<\/p>\n Via the FD-2 Orbiter Boom Sensor System (OBSS) scans, digital photography by the crew, and the R-bar Pitch Maneuver (RPM) just prior to docking on FD-3, all areas of Discovery\u2019s TPS were scanned or photographed.<\/p>\n The External Tank doors were verified to be completely closed with no paint stripe visible via RPM photography.<\/p>\n In all, Discovery is one of the cleanest \u2014 if not the cleanest \u2014 Orbiters to arrive at the ISS since Shuttle flights resumed in July 2005 following the Columbia accident.<\/p>\n Only 13 areas of Discovery\u2019s TPS were noted to be different from their pre-launch, baseline configuration.<\/p>\n Nine of these differences were located on the underside of Discovery on the underbelly acreage TPS, with the remaining four discrepancies all located on the Starboard OMS (Orbital Maneuvering System) Pod.<\/p>\n \u201cFrayed\/protruding arrowhead blanket has no affect on boundary layer transition,\u201d notes the latest DAT presentation on L2.<\/p>\n The frayed\/protruding arrowhead blanket is consistent with past-flight experience. The size of this frayed\/protruding blanket is estimated at less than 0.26\u2033 \u2014 well within the 0.7\u2033 observed flight history.<\/p>\n This frayed\/protruding blanket \u2014 as with the rest of the eight tile damage sites on the underside of Discovery \u2014 will have no effect on the Boundary Layer Transition Detailed Test Objective which will be carried out during Discovery\u2019s reentry into Earth\u2019s atmosphere.<\/p>\n Furthermore, of the nine lower surface damage sites, six were cleared by the preliminary DAT review, with only three tile damage locations requiring additional analysis.<\/p>\n These locations were \u201cassessed with depths provided by photogrammetry. All tile\/structure margins maintained,\u201d notes the latest DAT presentation.<\/p>\n Likewise the two protruding gap fillers on the Starboard OMS Pod remain bonded to the underlying surface of Discovery.<\/p>\n All tile and structural margins are maintained here as well and the gap fillers are not expected to liberate during reentry because ascent loads are three times higher than those of entry loads on this area of the vehicle.<\/p>\n \u201cFRSI plug retained in insert and liberation not expected as 1\u2033 of the plug remains in the insert,\u201d notes the DAT presentation and Mission Management Team meeting minutes.<\/p>\n However, should the felt plug liberate during entry, no damage to the OMS pod structure or critical damage to the Rudder Speed Brake is expected should the plug impact those areas during liberation.<\/p>\n As such, the DAT team was unanimous in declaring Discovery\u2019s TPS \u201cacceptable for entry.\u201d To be followed by the Late Inspections after undocking.<\/p>\n L2 members<\/em><\/em>: Documentation \u2013 from which 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":" STS-128 has successfully completed the second of three spacewalks, which focused on the replacement of an Ammonia Tank on the International Space Station (ISS). Meanwhile the Damage Assessment Team (DAT) have given an expansive roundup of their rationale to clear Discovery for entry, which was approved by the Mission Management Team (MMT). EVA-2: The second […]<\/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":[567,233,9205],"class_list":["post-41002","post","type-post","status-publish","format-standard","hentry","category-news","tag-eva","tag-iss","tag-sts-128"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/41002"}],"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=41002"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/41002\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=41002"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=41002"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=41002"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}See Also<\/h4>\n
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![\"neptec\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2009\/08\/neptec.jpg\" "\\"neptec\\"")
Currently, the team is reviewing the possibility of repressurizing the system\u2019s manifold 5 in the event that a contingency necessitating the use of the VRCS arises.<\/p>\n![\"A4\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2009\/09\/A4.jpg\" "\\"A4\\"")
\u201cTPS acceptable for entry \u2013 finished all ascent imagery and analysis and have no concerns for TPS during entry,\u201d notes the minutes from yesterday\u2019s Mission Management Team meeting.<\/p>\n![\"A3\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2009\/09\/A3.jpg\" "\\"A3\\"")
Of the nine lower surface damage locations, eight were noted as tile damages and one as a frayed\/protruding arrowhead blanket.<\/p>\n![\"A5\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2009\/09\/A5.jpg\" "\\"A5\\"")
The final area of interest on the TPS is a FRSI (Felt Reusable Surface Insulation) plug on the Starboard OMS pod. This felt plug was noted to be protruding in relation to its usual configuration.<\/p>\n