Design of Two RadWorks Storm Shelters for Solar Particle Event Shielding

Abstract

In order to enable long-duration human exploration beyond low-Earth orbit, the risks associated with exposure of astronaut crews to space radiation must be mitigated with practical and affordable solutions. The space radiation environment beyond the magnetosphere is primarily a combination of two types of radiation: galactic cosmic rays (GCR) and solar particle events (SPE). While mitigating GCR exposure remains an open issue, reducing astronaut exposure to SPEs is achievable through material shielding because they are made up primarily of medium-energy protons. In order to ensure astronaut safety for long durations beyond low-Earth orbit, SPE radiation exposure must be mitigated. However, the increasingly demanding spacecraft propulsive performance for these ambitious missions requires minimal mass and volume radiation shielding solutions which leverage available multi-functional habitat structures and logistics as much as possible. This paper describes the efforts of NASA's RadWorks Advanced Exploration Systems (AES) Project to design two minimal mass SPE radiation shelter concepts leveraging available resources: one based upon reconfiguring habitat interiors to create a centralized protection area and one based upon augmenting individual crew quarters with waterwalls and logistics. Discussion items include the design features of the concepts, a radiation analysis of their implementations, an assessment of the parasitic mass of each concept, and the result of a human in the loop evaluation performed to drive out design and operational issues. Nomenclature Acronyms ACS= Attitude Control System AES = Advanced Exploration Systems ALARA = As Low As Reasonably Achievable AM = Augmentation Module BEO = Beyond Earth Orbit CAD = Computer-Aided Design CLS = Cislunar Spacecraft CQ = Crew Quarter CPC = Common Protection Container CTB = Cargo Transfer Bag DSH = Deep Space Habitat ECLSS = Environmental Control and Life Support EMS = Emission of Solar Protons EVA = Extra Vehicular Activity EXAMINE= Exploration Architecture Model for IN-space and Earth-to-orbit FAX = Female Adult voXel FSP = Food Storage Pouch FY = Fiscal Year GCR = Galactic Cosmic Ray GOES = Geostationary Satellite HAL = Habitable Airlock HAT = Human Spaceflight Architecture Team HDU = Habitat Demonstration Unit HMC = Heat Melt Compactor HZETRN = High charge (Z) and Energy TRaNsport code ICWC = Iodinated Contingency Water Canister IMP = Interplanetary Monitoring Platform ISS = International Space Station KPP = Key Performance Parameter LEO = Low Earth Orbit MPCV = Multipurpose Crew Vehicle MPLM = Multipurpose Logistics Module OLTARIS = On-Line Tool for the Assessment of Radiation in Space PDF = Probability Density Function PED = Positive Expulsion Device PWD = Potable Water Dispenser Downloaded by PURDUE UNIVERSITY on July 25, 2015 | http://arc.aiaa.org |