**Equipment/ Regolith Interaction Issues for Planetary ISRU and
Construction**

Sally Shoop^1^, Barry Coutermarsh^1^, Paul Corcoran^2^

Long-term Moon and Mars missions will require planetary infrastructure
for *In-Situ* Resource Utilization (ISRU) and living facilities on a
scale previously unknown in planetary exploration. The construction of
these facilities plus ISRU tasks will require equipment capable of
excavating, transporting and accurately emplacing relatively large
masses of Regolith. These tasks need to be accomplished without the
traditional terrestrial techniques that utilize a suite of specialized
heavy equipment vehicles where each performs one or two tasks. The
planetary construction equipment will need to be light, compact, modular
and capable of performing several varied tasks in support of facility
construction and ISRU and capable of accomplishing these under
autonomous and/or manned control.

The current state-of-the-art in vehicle-terrain interaction and earth
moving equipment modeling includes sophisticated models ranging from
discrete element and finite element modeling of material movement using
buckets and blades to virtual reality simulations of equipment operation
and repair. The Lunar Regolith-Handling Construction Team will take
advantage of our experience in design and modeling of construction,
military and robotic vehicles, soft soil and snow mobility modeling and
extreme environment logistics, construction and snow handling to propose
solutions for planetary construction and ISRU equipment.

The issues that arise in the design of planetary construction equipment
are driven by the requirements of space transport, e.g. low payload mass
and volume restrictions, long and expensive travel times and by
planetary environmental characteristics such as low gravity, unique
regolith properties, electrostatic charging and near-vacuum atmospheres.
Furthermore planetary construction equipment will need to perform
several potentially unrelated tasks which may preclude optimizing its
design for Regolith handling alone. Probably the most important unknown
is how the Regolith will interact with and influence vehicle traction,
end-effector and implement use. Using low mass equipment to move
Regolith might require enhanced tractive or anchoring techniques due to
the difficulty of adding vehicle mass.

Efficient Regolith-Handling Equipment design requires that we understand
and can model the various mechanisms that influence and impact Regolith
excavation and transport. Scale model soil bin and laboratory
simulations will allow us to validate terrestrial-based numerical models
and machine performance simulations for designing in planetary
environments. Research needs include a thorough understanding of the
physical and mechanic properties of the material, the unique environment
and processes that will affect the lunar materials and their
utilization, new design methodology to accommodate and capitalize on the
unique aspects of planetary material handling and construction
techniques, a terrestrial simulant capable of scaling the important
properties and processes involved in equipment interactions, and
innovative concept development for enabling technologies.

1.USA-CRREL, 72 Lyme Road, Hanover, NH 03755-1290
<shoop@crrel.usace.army.mil>, <barry@crrel.usace.army.mil>

2.Caterpillar Inc., Technical Center Bldg. E, P.O. Box 1875, Peoria,
Ill., 61656-1875 <corcoran_paul_t@cat.com>