The Athena team utilizes high-performance multi-core computers (e.g., supercomputers) and sophisticated numerical techniques to design physiologic-equivalent ground-based analogs of the organ dose distribution incurred by astronauts. The results of this research will be the development a ground-based space radiation analog that exposes each major organ and tissue in a mammalian model to values of absorbed dose and radiation quality that correspond to those in astronauts. A physiological scalable analog that can simulate the non-homogenous space radiation environment in a laboratory setting.
The technology developed by Athena will include an apparatus to generate the radiation field, animal immobilization, and other components that utilize existing ground-based space irradiation facilities with no changes to the beam line infrastructure. This will enable NASA and its international and commercial partners real time observation of biological effects and greater understanding of the health risks associated with spaceflight.
The 90th percentile female tetrahedral-type phantom. Tetrahedral-type phantoms are a progression of surface-type phantoms where surface meshes are replaced with volume tetrahedrons. Tetrahedral-type geometry is easily incorporated in Monte Carlo codes and leads to faster radiation transport calculations, while preserving the original complexity of surface phantoms. Shown here is the female tetrahedral-type phantom used in the calculations. In this view, the skin, muscles, and residual tissues are hidden to showcase internal anatomy structures. The right side of the phantom was visualized with smooth surfaces, while the left side was visualized as a surface with edges, showing the tetrahedrons that comprise the different region
A close up of the midsection of the tetrahedral-type phantoms. Tetrahedral-type phantoms are constructed with volumes filled with varying sized tetrahedrons. In the image, the lines on the organs represent the various tetrahedrons used to define that volume. Volumes and regions defined in this manner depend only on the size of the tetrahedrons, of which there is no real limitation. While in large organs finely detailed tetrahedrons may not be needed, small volumes such as mucosa linings benefit greatly with this phantom type and can be modeled at the micrometer level.
The 90th percentile mass and height male (left) and female (right) phantoms were exposed to the simulated IVA spectrum representative of roughly one full day of exposure in space. Phantoms are shown without skin, muscle, and soft tissue to show internal organs and skeletal frame. The three-dimensional dose distribution is overlaid on the phantoms to show the anatomical relation of the dose distribution. All region doses in both phantoms are on the order of μGy.