Meteoroids threaten the safety of spacecraft. Currently, the NASA Meteoroid Engineering Model (MEM) estimates meteoroid flux according to a reference frame derived from the spacecraft (s/c) trajectory, while the NASA “Bumper-ii” code uses a reference frame fixed to the body of the s/c to evaluate damage to the s/c structure. It is therefore cumbersome to relate the environment to the s/c as it changes its trajectory or orientation. My algorithm uses quaternions to rotate a meteoroid flux estimate from MEM’s reference frame to the reference frame used by Bumper. I use quaternions, instead of Euler angles, to avoid singularities. Both algorithms define spheres divided into solid-angle bins surrounding the s/c. Each bin is assigned its respective meteoroid flux, thus creating a flux environment F(θ,φ), where θ and φ are spherical coordinates representing the direction each particle is moving. The environment sphere is then rotated to simulate a s/c orientation change of the opposite rotation. This rotation represents the difference between the MEM coordinate system and the body-fixed s/c coordinate system. Finally, a tally is made of the new (rotated) flux in each s/c flux bin.
|Tue Nov 13, 2012 12:40pm – 1:30pm Central Time|
|Engineering 1 room 102 (map)|