David Garcia, Air Force Institute of Technology; Robert Bettinger, Air Force Institute of Technology; Carl Hartsfield, Air Force Institute of Technology
Keywords: origami flasher, space-based mirror, survivability, debris impact
Abstract:
The imaging and inspection of Resident Space Objects (RSOs) is an increasingly important Space Situational Awareness (SSA) mission as space-faring nations and commercial enterprises alike seek to develop means to repair and refuel satellites, as well as de-orbit RSOs in order to reduce orbital debris. The lighting conditions for imaging and inspection are not always advantageous for a repair/refuel satellite; therefore, the use of mirrors deployed from servicer satellites is proposed to reflect solar energy in order to illuminate dimly lit RSOs. In terms of a general concept of mission operations, the servicer satellites would control the reflected light beam and be positioned to illuminate RSOs for imaging, inspection, repair, and/or refuel. The servicer satellite is assumed to be either a 12U or 27U CubeSat, therefore an investigation of folding the mirror into a compact state utilizing origami will be critical. Specifically, the use of cubic origami flashers will be necessary for CubeSat applications.
Currently, origami-based designs are being applied within various fields of endeavor. Mechanical folds are seen within the recreational outdoors industry where origami-based Kayaks are available for purchase and use. Research is being done in Brigham Young University using foldable Kevlar Shields that can be stowed and deployed easily by emergency response and Department of Homeland Security personnel. Other origami applications exist in the medical field with retractable and expandable stents, as well as foldable forceps, also known as “oriceps” for robotic surgical applications. Overall, both Brigham Young University and UC Santa Barbara have performed research applying origami flashers to solar panels. In the case of a space mirror, the origami flasher application can be used in the same fashion. Other folding-based reflectors have been implemented with spacecraft such as IKAROS, the James Webb Telescope, the Japanese Space Flyer Unit, and Star Shade.
Space-based mirror application research has largely remained dormant for the past two decades. It has recently come to the forefront due to technological limits being reached for large, monolithic space-based telescopes. This research will further space-based mirror research in two phases: novel structure development and physical experimentation to test on-orbit survivability. For the structure development phase, a prototype deployable mirror using an origami cube flasher will be designed and fabricated for use with a CubeSat bus, such as a 12U or 27U form factor. Additive manufacturing will be employed to fabricate the deployable mirror. For this method of fabrication, knowledge gaps include the following: (1) the appropriateness of using a thermoplastic polymer (e.g., ULTEM) to print the main structure of an origami flasher; and (2) the effectiveness of using heat-treated Ni-Ti (Nitinol) as an internal skeleton to the overall polymer structure, how it reacts to thermal cycling in space, and the mode in which Nitinol unfolds either passively or with a physical unfolding mechanism.
The physical experimentation phase will focus on the debris environment and assessing on-orbit survivability. Any space structure is subject to several critical environmental factors including charging, radiation, heating cycles, and meteoroid and space debris impact. Mirrors and gossamer structures are especially susceptible to micrometeoroid and space debris impacts due to their thin, non-rigid design and potentially large profile once deployed. Using a cold-gas gun at the Air Force Research Laboratory, the impact effects of simulated debris traveling at relative speeds congruent with operations in geosynchronous Earth orbit (GEO) and cislunar space will be ascertained for the additively manufactured origami flasher and mirror. The hybrid additive manufacture of a polymer and metal (e.g., UTLEM and Nitinol) is novel and may create structural weakness. Impact testing of the origami structure will reveal these weaknesses and provide an assessment regarding the structural integrity of hybrid additively manufactured origami structures for use with the space-based SSA mission.
Date of Conference: September 19-22, 2023
Track: SDA Systems & Instrumentation