Imaging satellite structures require the highest possible thermal stability in order to maximize imaging precision. As the sizes of optics increase to accommodate ever-present inherent resolution limitations, these structures continue to grow with the expectation of similar or better overall thermal stability. These requirements spurred the development and maturation of low-CTE carbon fiber tube structures. While production of the carbon fiber tubes themselves is well developed to produce lightweight, low CTE structures, the components that attach these tubes are still heavy and expensive to produce.
Mantis Composites proposes a solution to this problem utilizing in-house-developed continuous 5-axis carbon fiber 3D printers. The 3D printing capability this provides allows for 3-dimensional fiber paths that can enable the low-CTE benefits of carbon fiber composites while retaining the intricacy capabilities of machined metals. With support of a prior $50,000 Air Force SBIR Phase I grant and matching funds from Ball Aerospace, we successfully produced a three-pronged ‘PVC style’ connector demonstrator with 90% weight reduction and improved mechanical performance over an equivalent Invar-36 component. We also developed and performed initial validation steps on a bonding system for our components to tube structures. This scope of work brought the effective TRL for this application of our manufacturing process to 3.
The goal of this proposal is to utilize this same three-prong connector demonstration component to mature and develop applications specifically targeting low-CTE needs for applications such as optical benches and metering structures. During this Phase I, we will: validate, test, and modify existing bonding methods; validate predicted low-CTE results at a coupon level; adapt our three-prong connector design for low CTE filament by tuning processing parameters and fiber paths; and finally produce and mechanically test a full-scale tube and connector mock-up.
While IR-band imaging systems (identified in the solicitation) are perhaps the most valuable application of the proposed capabilities, the component volumes are small. We also see significant applications in large space-based structures more broadly. NASA’s push for long distance human spaceflight will require large collapsible, lightweight structures. While less CTE driven, the other requirements this brings match with the proposed technology. We see low CTE structures as a convenient scope-limited qualification bridge to these applications.
From the National Reconnaissance Office to private LEO earth imaging companies, increasing the thermal stability of optical systems on is necessary to increase resolution. Since tube-and-beam structures are common between NASA and non-NASA optical systems, with metal components being the limiting weight and thermal stability factor for both, the proposed scope of work is equally applicable to both