Structural and Radiation Shielding Properties of Non-parasitic, Multi-functional Microporous Carbon for Aerospace Applications 2007-01-3111

AFR, Inc. is developing a multifunctional Carbon material that, in addition to excellent radiation shielding characteristics, is appropriate for certain energy storage applications. As an excellent Hydrogen gas sorbent, it increases the usable storage capacity of a gas cylinder by ∼25% at 3500 PSI and by ∼150% at 500 PSI. Our ongoing NASA Langley funded study shows that when a sorbent-filled tank is charged with hydrogen, it provides shielding superior to polyethylene against most types of ionizing particles. Even as hydrogen is consumed, the carbon and tank ensure that significant radiation shielding capability is maintained. In addition to storing hydrogen, the carbon material also displays considerable strength. In this paper, we explore some of its mechanical properties that show this material is very versatile and highly multifunctional.

Vastly improved radiation shielding is a clear requirement for a potential manned mission to Mars or a long-duration base on the surface of the Moon. However, current shielding technologies are predicated upon systems dedicated solely to the task of shielding. Such single-use material adds substantially to the mass, and therefore expense, of space operations, without otherwise helping to accomplish mission objectives.

One approach to remedy these conflicting constraints is to modify other ship (or EVA suit) systems to maximize their radiation shielding properties, while still serving their primary purposes. Our carbon sorbent material takes this approach. Its performance in this key energy system application is excellent and the carbon itself is a better radiation shield against GCR's and SEP's than the excess Aluminum it can replace. As we explore its mechanical properties, additional functional roles such as micrometeorite protection or some structural applications may emerge.