Space Launch System: Tooling Up to Build the World's Largest Rocket
A wrench and hammer might be good for some building projects, but the nuts
and bolts found in a standard garage toolbox definitely wouldn't hit the nail on
the head when it comes to constructing a 321-foot, 5.5 million-pound rocket.
That's why engineers at NASA's Michoud Assembly Facility in New Orleans are
installing massive tools - one more than 170 feet tall - specifically designed and
built to weld together pieces of the core stage of the Space Launch System (SLS)
- NASA's new heavy-lift rocket that will send humans to deep space destinations,
including an asteroid and Mars.
"One of the challenges that we face in building this large core stage is to develop
world-class tooling using modern manufacturing methods in an affordable way,
while maintaining the scheduled first launch in 2017," said Tony Lavoie, manager
of the Stages Office at NASA's Marshall Space Flight Center in Huntsville, Ala.
"This tool set that we've developed for Michoud to build the core stage is a
perfect blend of those requirements and constraints."
Six substantial welding tools will be used to handle assembly of the new
cryogenic core stage on SLS. Suppliers worked with NASA and The Boeing
Company of Huntsville over the course of a year to design and build the tools.
Boeing is the prime contractor for the SLS Core Stage, including avionics.
The tools include:
The Circumferential Dome Weld Tool will be used to perform circumferential
friction stir welds in the production of dome assemblies for the SLS core stage
The Gore Weld Tool will perform vertical conventional friction stir welds in the
production of gore assemblies for the SLS core stage tanks. Gores are preformed
aluminum alloy dome segments that are welded together to make the dome.
The Circumferential Dome Weld and Gore Weld tools are special tooling for the
Enhanced Robotic Weld Tool -- used to make dome components for SLS.
The Vertical Weld Center is a friction-stir-weld tool for wet and dry structures on
the SLS core stage. It will weld barrel panels together to produce whole barrels
for the two pressurized tanks, the Intertank, the Forward Skirt and the Aft Engine
Section. It stands about three stories tall and weighs 150 tons.
The Segmented Ring Tool will use a friction-stir-weld process to produce
segmented support rings for the SLS core stage. The rings connect and provide
stiffness between domes and barrels.
The Vertical Assembly Center (VAC), where domes, rings and barrels will be
joined together to complete the tanks or dry structure assemblies. The tool also
will perform nondestructive evaluation on the completed welds. The VAC,
measuring 170 feet tall and 78 feet wide, is one of the world’s largest welding
tools. It is anticipated to be completed in 2014.
"It’s an exciting time to be a part of NASA’s team," said Rick Navarro, Boeing
operations manager at Michoud. "We’re already welding on the new tooling and
are gathering information we’ll need to start production welding. That old
saying, 'measure twice, cut once,' applies in spades when you’re building a 5.5
million-pound rocket. We do a lot of testing, validating and what we call
‘qualifying’ welds that ensure we have all the information we need to build with
100 percent quality assurance."
NASA and Boeing are designing, developing, building and testing the core stage
and avionics. The rocket also will use proven hardware from other programs like
the space shuttle -- a significant affordability benefit.
"We are one step closer to building the first core stage in what will hopefully be a
long line of rockets to support future NASA missions," said Lavoie. For more
information on SLS, see also:
SLS Fact Sheet (http://www.nasa.gov/pdf/664158main_sls_fs_master.pdf)
NASA SLS website (http://www.nasa.gov/exploration/systems/sls/)