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<\/em><\/font>L2, for expanded documents and insider information covering the space programs at work. To join L2, click the advert. Join soon, due to a pre-determined membership level.<\/p>\nInformation collated from several PRCB and SICB documents, all documents on L2.<\/p>\n
<\/em><\/font><\/font>The main focus of the evaluations once again centered on the balance between modifying the External Tank to reduce foam loss \u2013 and the level of modifications carried out before the flight of STS-121. Shuttle manager Wayne Hale has previously stated the need to stage the modifications with the backing of the subsequent flight data. <\/font><\/p>\n
The risk matrix, three columns across based on \u2018Severity\u2019 and four columns high based on \u2018Likelihood\u2019 is defined as follows:<\/p>\n \u2018Catastrophic: Hazard could result in a mishap causing fatal injury to personnel and\/or loss of one or more major elements of the flight vehicle or ground facility. Critical: Hazard could result in serious injury to personnel and\/or damage to flight or ground equipment which would cause mission abort or a significant program delay. Marginal: Hazard could result in a mishap of minor nature inflicting first-aid injury to personnel and\/or damage to flight or ground equipment which can be tolerated without abort or repaired without significant program delay.\u2019<\/p>\n Likelihood of occurrence is completed for each cause by assessing the controls that are in place and documenting them as probable, infrequent, remote, or improbable:<\/p>\n \u2018Probable: Expected to happen in the life of the program. Infrequent: Could happen in the life of the program. Controls have significant limitations or uncertainties. Remote: Could happen in the life of the program, but not expected. Controls have minor limitations or uncertainties. Improbable: Extremely remote possibility that it will happen in the life of the program. Strong controls in place.\u2019 <\/font><\/p>\n The \u2018probable\/catastrophic\u2019 evaluation is the worst rating on the risk matrix, yet this isn\u2019t consistent with the documentation that followed through from last week\u2019s PRCB meeting to the FRR. The full list of risks averaged \u2018remote or infrequent\/catastrophic\u2019 ratings \u2013 as the \u2018likelihood rationale\u2019 in the External Tank Accepted Risk Hazard Analysis Report, with each of the 16 areas discussed having a \u2018Severity Rationale: The worst case effect for this cause is catastrophic loss of life and\/or vehicle.\u2019 <\/font><\/p>\n Another NASA document noted the \u2018probable\/catastrophic\u2019 classification deemed the risk to be unacceptable for flight, while highlighting which departments of the Shuttle program disagreed with each other within NASA\u2019s System Integration Control Board (SICB). <\/p>\n \u2018SICB Chairman (SE&I) recommended approval of IHR IDBR-01, including classification of IFR Body and IFR Acreage debris risks as Infrequent Catastrophic. After listening to SICB discussion, SICB Chair\u00e2\u20ac\u2122s decision was based on interpretation of IFR guidelines for risk classification. Probable Catastrophic (red)-LOCV (loss of vehicle and crew) expected <\/b>in life of Program. Risk unacceptable for flight (paraphrased). Infrequent Catastrophic (yellow)-LOCV could <\/b>occur in life of Program. Risk accepted for flight (paraphrased). <\/p>\n \u2018The following SICB members concurred with this decision: Aerospace Corp, MOD, FCOD, USA, MK-SIO, KSC-PH, NA (MX non-concurs). The following members abstained from the polling: SRB, SSME, MSFC S&MA. The following members non-concurred: JSC Engineering, PSE&I, ET (incomplete review of IDBR-01). The following regular members were not present for polling: MSFC Engineering, RSRM, KSC technical authority.\u2019<\/p>\n <\/font> NASASPACEFLIGHT.COM RSS FEED \u2014> In what appears to be rationale for the risk to be classed as Probable\/Catastrophic, the document noted the reasons for drawing such a conclusion.<\/p>\n SpaceX (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n \u2018Engineering Analysis\/Engineering Division (EA) does not concur with describing the debris risk from Ice Frost Ramps as Infrequent\/Catastrophic. For the following reasons EA considers the risk Probable\/Catastrophic:<\/font><\/p>\n \u2018The release mechanism is not well understood which means time of release cannot be assured. There are no controls in place since the failure is a design flaw. Risk Assessment indices indicate a high probably (~ 1\/100) of exceeding tile capability which depends on repair capability to not be catastrophic.\u2019<\/p>\n As noted by NASA administrator Mike Griffin at the weekend, NASA would not be willing to fly STS-121 if there was such a level of risk as intimated by the risk matrix. The documents appear to point towards a need to find the correct classification of flying a shuttle with modifications which are yet to be tested in a full flight scenario.<\/font><\/p>\n Only a flight will allow managers to re-evaluate the next steps in finding the balance between improving safety and carrying out modifications that lack flight data.<\/font><\/p>\n **NASASpaceflight.com Job Opportunities**<\/font> New site design coming soon.<\/font><\/em><\/font><\/p>\n <\/u><\/p>\n","protected":false},"excerpt":{"rendered":" Flying with risk is hardly anything new for any space vehicle, not to mention the Space Shuttle. Assessing such risk was highlighted during the weekend\u2019s FRR (Flight Readiness Review) in which the \u201crisk matrix\u201d played a major role. Shuttle managers have decided to press ahead with the July launch of Shuttle Discovery, despite misgivings from […]<\/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":[],"class_list":["post-42039","post","type-post","status-publish","format-standard","hentry","category-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/42039"}],"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=42039"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/42039\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=42039"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=42039"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=42039"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Severity level is an assessment of the most severe effects of a hazard:<\/font><\/p>\n
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<\/font>The key areas concentrated on the potential of foam liberation from the ice\/frost ramps \u2013 which have been modified, but not to the extent wished for by some sections of the engineering community, most notably MSFC (Marshall Space Flight Center), who classed the tank as \u2018unacceptable for flight\u2019 after their call for further reductions and reshapes of the foam from the ice frost ramps was rejected. Other areas looked at the ability of an on-orbit repair of any damage incurred on ascent. **MSFC Claim \u2013 Article**<\/em><\/p>\n<\/font>STS-121 Mission T-Shirt. Use discount code \u2018nasaspaceflight\u2019 when ordering from Countdown Creations & receive 5% off!<\/p>\n
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<\/font><\/p>\n<\/font>\u2018The risk assessment mass of 0.08lbm is several times larger than the orbiter tile impact and damage capability. Ground testing, ET-120 dissection, and stress analyses have all confirmed the constant, repeatable occurrence of the failure mechanism. Flight history confirms that releases occur every flight and includes masses up to and exceeding the risk assessment mass.<\/font><\/p>\n
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