The role of robotics mobility is essential in the world of research because it allows humans to perform jobs that are dull, dirty, or dangerous without being physically present. A typical robot environment is one that is smooth and predictable. Screw-powered vehicles (SPV's) have commonly been used in these predictable environment situations such as terrestrial applications like mud and snow. However, a gap remains in SPV's traversing complex environments, particularly debris and granular material. The goal is to study the characteristics of how a SPV might move and generate force in such a granular environment for Earth and space. In our study, the chosen granular environment is soda-lime glass beads for easy characterization. This study with glass beads focuses on two separate approaches. The first approach is using a single screw rotating while the apparatus remains static and analyzing the forces that impact the screw. The second approach includes using a full body craft with two double helix screws and analyzing the translational velocity of the craft. This study presents both experimental and computational results using simulations with Multi-Body Dynamics (MBD) and Discrete Element Method (DEM) software packages to investigate the trends of SPV's in a granular environment.

Orbiting space debris is an active issue that affects the capability of space launch for future satellites, probes, and space shuttles, and it will become a nearly insurmountable problem without action. Debris of varying sizes and speeds orbit the Earth at a range of heights above the atmosphere and need to be removed to avoid damage to crucial equipment of active orbiting satellites including the International Space Station. Finding a feasible solution to space debris removal requires that several facets be covered to become a reality; these include being aware of the problem in magnitude and source. This literature assessment covers the magnitude of space debris in low-earth and geosynchronous orbit as well as collision events which have increased the amount of space debris. There have been efforts made by several space agencies to control the amount of space debris added to orbit by current and future launches over the last decade \u2014 serving as a temporary fix before removal can be executed. This paper explores known removal efforts through mitigation, projects conceived and tested by DARPA, related space policies and laws, CubeSat technology, and the cataloguing of known space debris. To make space debris removal a reality, roadblocks need to be removed to acquire permission from states or countries for space missions. For example, these restrictions are in place to protect the assets of several countries and organizations. Guidelines set to curb the growth of space debris fail to prevent the growth due to the restrictions for ownership rights making them not as effective. This paper covers space policy and laws, the economy, satellite ownership, international conflict, status of space debris, and the overall feasibility of space debris removal. It will then discuss currently proposed solutions for the removal of space debris. Finally, this paper attempts to weight the advantages and disadvantages of the idea that space debris removal should include the opportunity to recycle materials. For example, defunct satellites and other discarded space crafts could be used for future launches. It will conclude with a personal exploration of what materials can be recycled, what chemical processes can be used to break down materials, and how to combine recycling and chemical processes for space-based recycling stations between Earth and the moon. The overall question that drives the search for making space debris removal a reality is whether it is feasible in multiple areas including technologically, legally, monetarily, and physically.