“We are manufacturing the simulators for each
of the SLS elements now for destructive tests for shipment to Marshall. It will test all the stress
modes, and finally to failure to see the process
margins,” explained Whipps
The SLS core stage builds on heritage from NASA’s Space Shuttle Program and is based on the
Shuttle’s External Tank (ET). All 135 ET flight units
were built at Michoud during the 30 year Shuttle
program by Lockheed Martin.
“We saved billions of dollars and years of development effort vs. starting from a clean sheet
of paper design, by taking aspects of the Shuttle
… and created an External Tank type generic
structure – with the forward avionics on top and
the complex engine section with four engines on
the bottom,” Whipps elaborated.
“This is truly an engineering marvel like the External Tank was – with its strength that it had and
carrying the weight that it did. If you made our ET
the equivalent of a Coke can, our thickness was
about 1/5 of a Coke can.”
“It’s a tremendous engineering job. But the
ullage pressures in the LOX and LH2 tanks are significantly more and the systems running down the
side of the SLS tank are much more sophisticated.
Its all significantly more complex with the feed
lines than what we did for the ET. But we brought
forward the aspects and designs that let us save
time and money and that we knew were effective and reliable.”
The SLS core stage is comprised of five major
structures: the forward skirt, the liquid oxygen
tank (LOX), the intertank, the liquid hydrogen
tank (LH2) and the engine section.
The LH2 and LOX tanks feed the cryogenic
propellants into the first stage engine propulsion
section which is powered by a quartet of RS-25
engines – modified Space Shuttle main engines
(SSMEs) – and a pair of enhanced five segment
solid rocket boosters (SRBs) also derived from the
Shuttles four segment boosters.
The tanks are assembled by joining previously manufactured dome, ring and barrel
Graphic shows all the dome, barrel, ring and engine components used to assemble the five major structures of the core stage of NASA’s Space Launch System (SLS) rocket
in Block 1 configuration. Credits: NASA/MSFC
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