Experimental Testbed for Testing a Robotics Based Identification Method

Abstract

As satellite on-orbit service operations become increasingly aggressive and complex (such as on-orbit refueling, rescuing, repairing, etc.), the need for identifying varied inertial properties of a satellite is becoming a critical task. The importance of this task stems from the dependence of spacecraft’s guidance, navigation and control system on these properties. In order to accurately control a spacecraft, its control system must be capable of fully identifying these properties as they change. Previous techniques use thruster firing or momentum wheels to accomplish this task. However a newly developed robotics based method requires measuring the spacecraft’s velocity changes only, which can be induced by an onboard robotic arm powered by solar energy. This paper gives a brief overview of this method and then focuses on the design of experimental verification of the method. The verification consists of a series of experiments including a simulated microgravity test onboard the NASA JSC Reduced Gravity aircraft in order to accurately simulate an environment similar to a flying satellite in orbit.

Development of a suborbital flight experiment for validating a satellite inertia identification method

“…Two sets of 6-DOF testing have been performed. The first series of tests have already been documented in [9] and [10]; while the other most recent set is the primary topic of this paper. A brief discussion of the 3-DOF test method that is in development will also be provided.…”

“…Therefore, an undergraduate research team has been making efforts to experimentally test the algorithm using various affordable approaches. The team designed a flight experiment unit and flew the experiment with NASA's C-9 microgravity flight program in 2008 [9] and 2009 [10]. The experiment unit consisted of a "satellite", a single-DOF robotic arm, and an onboard measurement and data processing system.…”

“…Detailed description of our attempts for this type of experiment have been reported in references[9][10].…”