You are here
Research Within Coder
This is a sample entry in the modeling category of research within CODER.
Many different methods have been proposed to address the issue of the growing orbital debris population. Impacts with large debris objects (i.e. spent upper stages, defunct, intact satellites) are of particular concern, since a collision with one of these objects could produce many small objects, increasing the likelihood of further collisions. This project is developing a comparison of proposed orbital technologies for removing large, intact objects from low Earth orbit. Software is being developed to design spacecraft to perform debris removal, taking into account the debris removal method used, the propulsion systems used, and the mission profile, with special attention given to the cost of such missions, and the risk they pose to active satellites and human life.
One of the many challenges associated with the remediation of large debris objects is capture in the presence of redidual angular momentum. This research looks at the possibility of zeroing the residual rotation of such objects using laser ablation from several meters away from the object before attempting capture. The advantage of such an approach is not requiring any mass consumables. Simulations have been conducted that account for laser characteristics and spot size on the ablation process, accessibility, targeting and optimization of the ablationpoints and they dynamics of 3D rotation. Results show that reduction of rotation rates to below acceptable capture rates can be achieved within hours or days, depending on the initial angular momentum of the object.
Laser propulsion is the process of removing material from the surface of a solid or fluid using a laser to generate thrust. Using a short pulse duration laser this is achieved via ablation, a non-thermal process where a solid material is converted to a directed plasma plume. At SHARC, a ps-pulsed 1064nm laser is used to ablate materials in vacuum. Using a custom designed time-of-flight spectrometer, the velocity, charge and mass distribution of the ions and nanoparticles in the plume are determined. A thrust stand is used for a direct force measurement. Laser ablation has applications in debris removal and asteroid mitigation, and materials to be tested include aluminum and rocky materials. In addition, the ablation plume can be used to simulate ion and nanoparticle bombardment in the space environment.