What looks like NASA’s Orion capsule, costs about the same
as an Orion capsule but isn’t made of metal? Why that would be NASA’s Composite
Crew Module, a structural prototype commissioned by NASA to determine if there
would be any advantages to using new polymers to fabricate its planned
replacement for the retiring space shuttles.
The NASA Engineering and Safety Center, set up in the wake
of the Columbia accident to provide independent testing, analysis and
assessments of the agency’s high-risk programs, has been studying the
alternative Orion capsule for about three years.
The NESC found that an alternative Orion was feasible but a
detailed design would be needed to ascertain if it could meet mass requirements
and manufacturing concerns. NASA told it to go ahead and build one.
Here’s a quick synopsis of the project from NSEC’s website:
The team … focused on a design that utilizes
aluminum honeycomb sandwich and solid polymer matrix laminate material systems.
The design integrates the capsule backbone with the floor and pressure shell
walls, which helps share the structural loads — particularly important for
water landings. The design also trims the capsule by about 150 pounds. The
capsule is constructed in two major sections: an upper and a lower pressure
Manufacturing of the prototype began last October and was
finished in July. Testing is under way.
Preliminary results are not particularly promising, as any
cost savings in weight and manufacturing are eroded by the alternative Orion’s
more complex design. Engineers also determined that the composite capsule would
take longer to build due to manufacturing changes associated with switching
from metallic materials .
NASA did like the composite’s clam-shell design and is
considering using it for the operational vehicles. NESC also concludes
that using composites reduces the number of parts needed to manufacture and
maintain the vehicles, which cuts life-cycle costs.
“Throughout the manufacturing phase, a number of
‘unknown unknowns’ materialized, giving the team the opportunity to evaluate
and demonstrate the inspectability and repairability of the (composite)
design,” NESC said.
(Alternative Orion capsule, ready for pressure tests.