Jonathan Michael Hinkle

Lunar Surface Systems Concept Study: Minimum Functionality Habitation Element

The primary result of the Minimum Functionality Habitat Element study was a concept level lunar habitat that provided the minimum functionality required to support the NASA prescribed reference mission. The habitat configuration was derived using an iterative system engineering process. The habitat functions; from pre-launch to operational environments, in packed/deployed and manned/unmanned modes, and operational support functions of the habitat, were identified by analyzing the reference mission. Functions were identified for explicit requirements and needs. These functions were collected by categories without association to any particular method, configuration or design solution for providing that function. The categorization and grouping provided a general logic to ensure identifying and capturing all required functions. No functions were included unless traceable to an identified habitat need or stated requirement. The functions were then analyzed to find areas of commonality. These commonalities were then used to identify how the functions could be most effectively combined to minimize the habitat systems and resources. In this evaluation process, any valid constraints were considered in selecting acceptable implementation methods. For example, regolith piled around and on the habitat walls is a very effective thermal, MMSE and radiation environmental control resource. However, it is not a viable option because the lack of infrastructure to move the regolith, according to the reference mission. The final result of the study was a conceptual design and definition of a ‘bare bones’ or minimum habitat element that incorporates the benefits of flexible materials.

Design Development and Testing for an Expandable Lunar Habitat

ILC Dover, under contract by NASA Langley Research Center, and in cooperation with NASA Johnson Space Center is designing and manufacturing an expandable lunar habitat. This cylindrical habitat, or Engineering Development Unit (EDU), is a hybrid system with two hard endcaps and a softgoods section in the center. The softgoods pack into the endcaps and the unit roughly doubles in length upon deployment. The softgoods is a multi-layer laminate of materials with each layer optimized for the desired function. Protection to the habitat from potential threats and unfavorable environmental conditions will be provided by various flexible materials. The Micrometeoroid/Orbital Debris layer shatters and absorbs hypervelocity particles, the Multi Layer Insulation grants thermal and potentially radiation protection, and the outer layer prevents abrasion damage. The remainder of the softgoods consists of a restraint system and bladder layer to handle internal pressure loads and retain gas respectively. The restraint layer uses a webbing net construction with a coated fabric to carry the pressure loads up to 9 psi. Gas retention is accomplished by the use of a coated fabric and an O-ring seal. All of these materials are flexible and amenable to folding without sustaining damage. The flexibility of the cumulative laminate will enable the structure to be folded and packed multiple times. On-going component level testing is being conducted to validate hybrid interfaces, creep knockdowns, and manufacturability. Upon completion in early 2009, the EDU will serve as a test bed to evaluate the dynamics of deploying a large system, to critically examine softgoods interfaces, and to determine methods for outfitting an expandable system. This paper presents an overview of the design and component testing for the Expandable Lunar Module.

Testing and Application of Numerically Determined Expandable and Foldable Space Structures

Expandable space structures offer advantages for long duration exploration by providing a maximum amount of operational volume at a minimum transportation cost. The current research is focused on using the dynamic properties of the folding process to yield a new class of deployable surfaces and linkages. Numerically determined deployable and foldable surfaces were created for habitat configurations. Initial small scale habitat prototypes were created to demonstrate the technology. The lessons learned from the prototypes are used to survey other applications of the technology in expandable space structures. The result is a study on foldable structures, which deploy in a predictable manner, in a variety of applications.