Simulations of directed energy thrust on rotating asteroids

Janelle Griswold; Jonathan Madajian; Isabella Johansson; Krysten Pfau; Philip Lubin; Gary B. Hughes; Aidan Gilkes; Peter Meinhold; Caio Motta; Travis Brashears; Qicheng Zhang

doi:10.1117/12.2188476

Translator Disclaimer

8 September 2015 Simulations of directed energy thrust on rotating asteroids

Janelle Griswold, Jonathan Madajian, Isabella Johansson, Krysten Pfau, Philip Lubin, Gary B. Hughes, Aidan Gilkes, Peter Meinhold, Caio Motta, Travis Brashears, Qicheng Zhang

Author Affiliations +

Proceedings Volume 9616, Nanophotonics and Macrophotonics for Space Environments IX; 961606 (2015) https://doi.org/10.1117/12.2188476
Event: SPIE Optical Engineering + Applications, 2015, San Diego, California, United States

Abstract

Asteroids that threaten Earth could be deflected from their orbits using directed energy to vaporize the surface, because the ejected plume creates a reaction thrust that alters the asteroid’s trajectory. One concern regarding directed energy deflection is the rotation of the asteroid, as this will reduce the average thrust magnitude and modify the thrust direction. Flux levels required to evaporate surface material depend on surface material composition and albedo, thermal, and bulk mechanical properties of the asteroid, and rotation rate. The observed distribution of asteroid rotation rates is used, along with an estimated range of material and mechanical properties, as input to a 3D thermal-physical model to calculate the resultant thrust vector. The model uses a directed energy beam, striking the surface of a rotating sphere with specified material properties, beam profile, and rotation rate. The model calculates thermal changes in the sphere, including vaporization and mass ejection of the target material. The amount of vaporization is used to determine a thrust magnitude that is normal to the surface at each point on the sphere. As the object rotates beneath the beam, vaporization decreases, as the temperature drops and causes both a phase shift and magnitude decrease in the average thrust vector. A surface integral is calculated to determine the thrust vector, at each point in time, producing a 4D analytical model of the expected thrust profile for rotating objects.

Citation Download Citation

Janelle Griswold, Jonathan Madajian, Isabella Johansson, Krysten Pfau, Philip Lubin, Gary B. Hughes, Aidan Gilkes, Peter Meinhold, Caio Motta, Travis Brashears, and Qicheng Zhang "Simulations of directed energy thrust on rotating asteroids", Proc. SPIE 9616, Nanophotonics and Macrophotonics for Space Environments IX, 961606 (8 September 2015); https://doi.org/10.1117/12.2188476

ACCESS THE FULL ARTICLE