Autor Wątek: Katastrofa Challengera (STS-51-L)  (Przeczytany 9666 razy)

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Odp: Katastrofa Challengera (STS-51-L)
« Odpowiedź #45 dnia: Luty 01, 2018, 02:47 »
Lost Innocence: Remembering the Sacrifice of the Challenger Seven (Part 1)
By Ben Evans January 29th, 2018

Next, turbine temperatures increased due to the leaner fuel mixture feeding into the combustion chambers from the External Tank. Otherwise, the Rogers report continued, “engine operation was normal.” They did not contribute to the loss of 51L. Nor did the gigantic tank itself, of which 20 percent was recovered, mostly debris from the inter-tank and the lowermost hydrogen section. Initial speculation that there had been premature detonation of range safety explosives was discounted, partly because the unexploded ordnance was among the debris, as were theories of structural imperfections in the tank’s design or damage incurred at liftoff. The possibility of a liquid hydrogen leak at liftoff was also dismissed, since it would immediately have been ignited by the exhaust from the Solid Rocket Boosters or main engines and would have been evident in the downlinked telemetry data.

In total, around 30 percent of Challenger was found, and inspections revealed that she had disintegrated as a result of massive aerodynamic overloads, with no evidence of internal burn damage or exposure to explosive forces. Chemical analyses indicated that her right side had been sprayed with hot gases from the leaking SRB, but telemetry indicated that all of her systems operated normally until shortly prior to the breakup. No problems were detected with either of her payloads. The Spartan-203 free-flying solar satellite was unpowered during ascent and the deployment ordnance for the Inertial Upper Stage (IUS) and the Tracking and Data Relay Satellite (TDRS-B) showed no indication of having prematurely activated.

Missed Warnings: The Fatal Flaws Which Doomed Challenger 32 Years Ago (Part 2)
By Ben Evans January 30th, 2018

A little over three weeks later, on 30 October 1985, Challenger flew Mission 61A, experiencing nozzle O-ring erosion and blow-by at the SRB field joints; neither of these problems were identified at the Flight Readiness Review for the next mission, 61B, in November. Indeed, that flight also suffered nozzle O-ring erosion and blow-by. By early December, in response to these problems, Thiokol recommended that their testing equipment needed to be redesigned.

Only days later, on the 10th, the company requested closure of the O-ring critical problem issue, citing satisfactory test results, future plans, and work carried out thus far by its task force. This closure request was harshly criticized by the Rogers investigators. One panel member pointed out to the Thiokol senior managers: “You close out items that you’ve been reviewing flight by flight—that have obviously critical implications—on the basis that, after you close it out, you’re going to continue to try to fix it. What you’re really saying is [that] you’re closing it out because you don’t want to be bothered.”