Available at: http://digitalcommons.calpoly.edu/theses/1528
Date of Award
MS in Aerospace Engineering
Predicting the mass, position, and velocity of an object during its reentry are critical to satisfy NASA and ESA requirements. This thesis outlines a 3-D orbit and mass determination system for use on low earth orbit as applicable to general objects, of various material and size. The solution uses analytical models to calculate heat flux and aerodynamic drag, with some basic numerical models for simple orbit propagation and mass flow rate due to ablation. The system outlined in this thesis currently provides a framework for rough estimates of demise altitude and final mass, but also allows for many potential accuracy and speed improvements.
77 aerospace materials were tested, in solid spheres, cubes, and cylinders; it was found that materials with low latent heat of fusion (less than 10 kJ/kgK) demise before reaching the ground, while materials with higher melting point temperatures (over 1200K), high specific heats, and high latent heat of fusion (over 30 kJ/kgK) lose small amounts of mass before hitting the ground at speeds of 200-300m/s . The results of this thesis code are validated against NASA's Debris Assessment System (DAS), specifically the test cases of Acrylic, Molybdenum, and Silver.