With STS-125 delayed until at least mid-February, Atlantis has completed her trek back to the Vehicle Assembly Building (VAB). Once secured inside the historic building, engineers will evaluate damage to her External Tank (ET-127) \u2013 which suffered several dings via a falling stainless steel support rod at the weekend.<\/p>\n
\nAtlantis is now expected to avoid a de-stack, following an engineering evaluation into potential requirements that would have favored the orbiter heading back to the home comforts of her OPF (Orbiter Processing Facility).<\/p>\n
Those latest evaluations focused on the tire pressures \u2013 which naturally decay over time. Data shows the pressures will be acceptable for landing \u201cas far away as April\u201d \u2013 making a February launch target within spec.<\/p>\n
Engineers will continue to monitor Atlantis\u2019 health during the couple of months she\u2019ll be housed in the VAB, with the option to call for a de-stack if it is deemed to be in her best interests.<\/p>\n
Other factors include the possibility Wing Leading Edge (WLE) inspections may be required, Main Landing Gear (MLG) door seal compression measurements, and moisture levels on her Payload Bay Doors.<\/p>\n
Most of Atlantis\u2019 hypergolics have been offloaded, should the de-stack option be taken in the coming weeks. This mitigates the undesirable offload of large quantities of the hazardous hypers in the OPF, in the event of a rollover back to her barn.<\/p>\n
\u201cIntegrated preps for rollback began last week and continued through weekend, following the SCAPE (Self-Contained Atmospheric Protection Ensemble) operation,\u201d noted Monday processing information on L2, relating to the hypergolic propellant offload ahead of rollback.<\/p>\n
During the offloading activities, one minor issue was noted with the pressures in the Left Reaction Control System (LRCS) tanks \u2013 which was mitigated by increasing the pressure in the associated helium tank.<\/p>\n
NASA mission patches (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n \u201cLRCS He Tank and LRCS propellant tank equalized. The Delta P should have been greater than 6 PSI for rollback to the VAB per OMRSD (Operational Maintenance Requirements and Specifications Document),\u201d added Monday processing information.<\/p>\n \u201cThe He QD (Quick Disconnect) was mated to the vehicle, the manual valve was closed, and the tank was pressurized. S0072 operations then resumed. An OMRSD waiver was required for taking readings with the Heise gages on the panels.\u201d<\/p>\n This action was called to avoid the potential migration of the hypergolic propellant into the pressurization system, which may of caused issues for required locking of the isolation valves.<\/p>\n Meanwhile, following an incident on Saturday, Atlantis\u2019 tank \u2013 ET-127 \u2013 will also require engineering evaluations, due to what is currently being classed as \u2018dings\u2019 on the ET, caused by a liberated stainless steel support rod on Saturday.<\/p>\n Atlantis herself has avoided any serious damage to her TPS (Thermal Protection System) during the 3.5 foot long rod\u2019s fall \u2013 which was later found on the floor of the MLP (Mobile Launch Platform).<\/p>\n \u201cOn Saturday morning a 3\u2032 1\/2\u201d stainless steel support rod that is used for the R\/H FRCS (Right Hand Forward Reaction Control System) spill protection was found on the MLP \u201c0\u201d Level between the Orbiter and ET (Inboard of the Left Hand Solid Rocket Booster),\u201d noted processing information on L2.<\/p>\n \u201cInitial inspections on the dropped tubing found several dings to the External Tank which could be possibly related damage from the tubing.<\/p>\n \u201cOrbiter TPS personnel performed a preliminary inspection of the thermal protection system. The Orbiter was inspected from the 207 level down using binoculars. No Orbiter TPS damage was noted.\u201d<\/p>\n The only remaining issue for STS-125 \u2013 relating to a faulty MDM (Multiplexer\/Demultiplexer) card \u2013 will be mitigated by its replacement later this week inside the VAB.<\/p>\n \u201cTroubleshooting on MDM OA2 was completed last week and indicated that the MDM has a bad port and will need to be replaced,\u201d added processing information. \u201cThe plan is to replace the MDM in the VAB following the 1st power up of the vehicle, which is scheduled for Wednesday.\u201d<\/p>\n The now-vacated Pad 39A will undergo preparations to receive Endeavour at the weekend, as she prepares for the November 14 launch of STS-126 to the International Space Station (ISS). Flight Readiness Review (FRR) based mission previews and processing will follow over the coming days.<\/p>\n L2 members<\/em><\/em>: All 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><\/em><\/p>\n","protected":false},"excerpt":{"rendered":" With STS-125 delayed until at least mid-February, Atlantis has completed her trek back to the Vehicle Assembly Building (VAB). Once secured inside the historic building, engineers will evaluate damage to her External Tank (ET-127) \u2013 which suffered several dings via a falling stainless steel support rod at the weekend. Atlantis is now expected to avoid […]<\/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":[3660,9236,8290,1701],"class_list":["post-41286","post","type-post","status-publish","format-standard","hentry","category-news","tag-atlantis","tag-et-127","tag-sts-125","tag-vab"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/41286"}],"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=41286"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/41286\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=41286"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=41286"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=41286"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}