LEOPARD: Low Earth Orbit Project for the Acquistion and Recovery of Debris

摘要

Orbital debris is a significant threat to spacecraft and human spaceflight existing in Low Earth Orbit (LEO). It is vital to take measures to remove debris from LEO to ensure a safe environment for the operation of these spacecraft and future missions. One way to accomplish this is to actively rendezvous with, capture, and remove debris using a capture system mounted to a spacecraft bus. The goal of the LEOPARD project is to design and build a debris capture system (DCS) capable of securing debris in the size range of 14-40 cm. By using orbital dynamics models and assuming the spacecraft bus can perform the required rendezvous and docking maneuvers, design requirements are imposed on the system. These requirements include the ability to capture two pieces of 40 cm debris at an incoming relative velocity of 0.18 m/s. In addition, the system must have the capability to capture debris with a position error of 3 cm and a relative pointing error between the capture device and debris of 3 degrees. To meet these design requirements, the LEOPARD system is an octagonal cylinder with a single opening which employs a passive system of interior bristles, set at an angle, to decelerate and secure the debris. A set of locking doors further ensures that any debris within the capture system cannot escape. During acquisition, the debris will be detected by a network of curtain sensors which will provide a signal to the processor that will be used to determine when to close. The system is designed so that it can accommodate the debris position error with a factor of safety of 2 and the pointing error with a factor of safety of 3. A full system test in a lg earth-based environment that simulates the capture scenario will be completed to measure the ability of the system to safely capture and secure debris and quantify the extent to which the design requirements were met. Details of the capture system design, estimated performance, and initial testing results will be presented in this document.