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Posts tagged External Tank

Not Much Opportunity for Shuttle Extension

I’m at Michoud this week on business, and had the opportunity to visit the factory today for the first time in nearly a year.

What a change ten months can make.

While last year, the dome tooling was still mostly in place (a few of the mechanical assembly pedestals had been pulled up), most of the mechanical assembly area and associated material cribs have been cleared out, leaving behind only the more complicated tools used for NC machining of the SRB fittings. Last year, there was still a pair of LOx tanks in post-proof inspection near the end of the production line, and an LH2 tank which had just had its forward dome (the last major segment) welded on. Today, all of the weld tools (domes, barrels, ogives, and major weld) had been mothballed and wrapped up, along with the large milling machines and lathes used to trim the various segments – it was like walking through a winter storage facility filled with shrink-wrapped boats.

What impressed me the most, however, was that for the first time in twelve-plus years, I saw areas of the factory with the lights turned off.

What this suggests is that there isn’t any hardware work going on to extend the Shuttle program beyond the number of tanks currently on-hand or in final assembly. If, as rumored, NASA is directed to extend the Shuttle program, they’d better start soon if they don’t want to end up with the long gap such an extension would be meant to avoid or minimize – due simply to the time lag in tank manufacturing.  And if what I was told about spares is true, it may only be possible to manufacture two additional tanks, assuming at that that everything would go perfectly and none of the spare components on order or in house have unrepairable defects or damage. With the one flightworthy tank I’m told will be left over at the end of the Shuttle program, that means an extension of at most three flights before the supply chain would need to be restarted — at considerable expense and delay.

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The Last SSME Test?

Last year I saw the scrapping of the Orbiter tooling, this May I got to see what will most likely be the final Shuttle External Tank going through the major weld stations at Michoud, and now they’ve run the final SSME test at Stennis:

With 520 seconds of shake, rattle and roar on July 29, NASA’s John C. Stennis Space Center marked the end of an era for testing the space shuttle main engines that have powered the nation’s Space Shuttle Program for nearly three decades.

This was the final planned test of a main engine for the shuttle, which currently is set to retire next year. More than 34 years ago, on June 27, 1975, Stennis engineers conducted the first test on one of the world’s most sophisticated rocket engines…

At one point, all three test stands at Stennis were involved in shuttle engine testing. Today, testing for the program occurs on the A-2 Test Stand as Stennis engineers prepare the A-1 Test Stand for testing the J-2X engine currently in development. That engine will help power the Ares I and Ares V rockets that will take humans back to the moon and possibly beyond as part of NASA’s newest space challenge – the Constellation Program.

NASA assigned Stennis to test space shuttle main engines in 1971. Prior to the first shuttle flight, Stennis engineers conducted some 500 tests on the engine and its components. They also test-fired the three-engine cluster arrangement – the main propulsion test article – that is used to power the shuttle, an accomplishment some called the facility’s “finest hour.”

Luckily, I got to see one of these tests back in April 2001:

SSME Hot Fire, April 21, 2001

Quite impressive – even from only about 200 yards away, the sound was felt more than heard.

With any luck I’ll get to see one or more of the Orbiters up-close next week while at KSC on business, but I still need to fit in a launch trip before the program ends.

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