{"product_id":"2940148761457","title":"SSME 0523 TEST 902-772 FAILURE INVESTIGATION FINAL REPORT","description":"Space Shuttle Main Engine (SSME) 0523 was assembled as a unique development engine\u003cbr\u003efor a specific series of tests. The plan for the test series was to demonstrate safe operation\u003cbr\u003eof the Pratt \u0026amp; Whitney High Pressure Fuel Turbopump (HPFTP\/AT) at the High Pressure\u003cbr\u003eFuel Turbine discharge temperature (HPFT DS T) redline values. The engine was in a\u003cbr\u003ehybrid Block I\/II configuration with a standard throat Main Combustion Chamber (MCC)\u003cbr\u003eand a HPFTP\/AT. The major objective of the first test in the series was to characterize\u003cbr\u003ethe effects of Coolant Control Valve (CCV) position on HPFT DS T.\u003cbr\u003eDuring the assembly of SSME 0523, Permacel P-670 (LOX) tape was introduced into the\u003cbr\u003efuel system during some “hands on” process (temporary closure, contamination barrier,\u003cbr\u003eunintentional introduction, etc.). A list of the probable locations of introduction is\u003cbr\u003ediscussed in Section 7.6. Despite normal processing inspections, the tape contamination\u003cbr\u003ewent unnoticed and was left in the fuel system during the remainder of assembly and pretest\u003cbr\u003eactivities.\u003cbr\u003eOn June 16, 2000, test number 902-772 of SSME 0523 was conducted on test stand A2 at\u003cbr\u003eStennis Space Center (SSC). The test was scheduled for a total duration of 200 seconds.\u003cbr\u003eA thrust profile of the planned test is provided in Figure 6.0-1.\u003cbr\u003eAt engine start, the tape contamination was forced downstream in the fuel system,\u003cbr\u003eeventually coming to rest as debris in both the Fuel Preburner (FPB) injector and\u003cbr\u003eOxidizer Preburner (OPB) injector. The amount of debris in the FPB was sufficient to\u003cbr\u003eblock multiple fuel inlet holes of several FPB injector elements in localized areas. This\u003cbr\u003eblockage caused a localized high mixture ratio area in the preburner without affecting\u003cbr\u003eoverall engine system performance. Data analysis indicates a localized temperature\u003cbr\u003eincrease occurred in the vicinity of HPFT DS T Channel A (flight instrumentation\u003cbr\u003elocation) and the HPFT DS T KG2dT (ground test instrumentation location) beginning at\u003cbr\u003eapproximately 2.7 seconds. The HPFT DS T Channel B measurement and the HPFT DS\u003cbr\u003eT measurement at KG2cT remained at nominal values. All other performance parameters\u003cbr\u003eindicated normal engine operation at this time.\u003cbr\u003eThe localized temperature increase caused melting of the turbine inlet housing struts and\u003cbr\u003efirst stage vanes in the HPFTP\/AT. At 4.97 seconds, all three airfoils on a first stage vane\u003cbr\u003esegment were melted through the chord, causing local structural failure of that segment of\u003cbr\u003evanes. The inner platform of the vane segment fell into the hot gas flow stream impacting\u003cbr\u003ethe first stage blades. This caused the first stage blades to fail creating significant\u003cbr\u003eHPFTP\/AT rotor imbalance. Data analysis indicates that the HPFTP\/AT synchronous\u003cbr\u003evibration amplitudes increased sharply to levels significantly higher than nominal\u003cbr\u003eoperation. The sharp increase in vibration levels were followed by a drop in HPFTP\/AT\u003cbr\u003eperformance and a corresponding response by the engine control system attempting to\u003cbr\u003erecover performance.","brand":"ReadCycle","offers":[{"title":"Default Title","offer_id":47111668269296,"sku":"2940148761457","price":2.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0737\/7593\/9824\/files\/2940148761457_p0.jpg?v=1763707924","url":"https:\/\/shop-qa.barnesandnoble.com\/products\/2940148761457","provider":"Barnes \u0026 Noble (DEV)","version":"1.0","type":"link"}