SPACE BENEFITS
Understanding the extensional rheology
of a complex fluid such as a liquid
polymer is key for containerless
processing because the absence of the
bounding walls of a container or vessel
removes the shearing component of the
deformation, which typically dominates
Earth-based processing operations. The
resulting flow is thus shear-free or
extensional in character. Containerless
processing is a central component in the
development of in-situ fabrication
technology, such as a means of
producing new parts on demand or
replacing existing parts or tools. This
represents a critical element in the
evolution of an autonomous exploration capability. In-situ fabricated parts, which may include
both new and recycled materials, will be composed of plastics, filled polymers, metals,
ceramics, and composites. SHERE plays a role in this area by measuring, in microgravity
conditions, a material property that has a direct connection to in-situ manufacturing and
fabrication of polymeric parts. In-situ manufacturing operations can occur in microgravity or
reduced gravity levels (eg, on the moon or Mars) and may include, for example, the extrusion
and processing of thermoplastic elastomer films, which are very resilient and can be made thin
and lightweight. These elastomeric materials may form the basis of adhesives and fillers utilized
in a wide variety of repair applications, especially under a reduced gravity environment, such as
the repair of space suits or other similar materials. Understanding and exploiting the ability to
fabricate new parts in-situ from a limited number of precursor components is critical in future
space missions where weight plays a critical role in the overall cost of a mission. Additionally,
in-situ repair provides a means of maintaining systems during transport and during future
exploration missions.
RESULTS
Results will be published upon completion of data analysis.
This investigation is ongoing and additional results are pending publication.
SHERE experimental hardware assembled in the
Microgravity Science Glovebox (MSG) on the
International Space Station (ISS). NASA’s Glenn
Research Center, Cleveland, Ohio image.