Radiation effects are well known to cause significant degradation in polymer materials. Low earth orbit (LEO) radiation exposures cause ionization potentials that can undermine mechanical properties of polymers. In particular, small scale degradations can undermine carbon / polymer composite mirrors used in imaging applications. A high-specularity surface finish is required for optical mirrors and that surface is vulnerable to radiation ionization degradation thereby undermining the optical performance of the mirror in that environment. Experiments involving radiation ionization and its effects on replicated carbon/polymer composite mirrors will be discussed; 6 replicated carbon/polymer composite mirrors on the Materials on the International Space Station Experiment, MISSE 7A and MISSE 8, the replicated RICH mirror the Alpha Magnetic Spectrometer (AMS-02) and testing on the RICH 1 replicated mirrors in the LHCb experiment. Results are favorable for optically coated composite mirrors in terms of mirror figure, reflectivity and surface finish, but not so on uncoated polymer mirrors.

The portability of meter-class telescopes has been limited by the weight of the mirror, tube assembly and the mount required to provide pointing and tracking. The novel lightweight carbon fiber reinforced polymer telescopes being developed for array population at the Naval Prototype Optical Interferometer are orders of magnitude lighter than traditional telescopes. When combined with a lightweight carbon fiber mount, these telescopes will be easily transportable from one telescope station to another to change the interferometer baseline. The mount for a lightweight telescope is currently under development at Composite Mirror Applications, Inc. This paper reports on the design constraints of the mount, the scalability to larger aperture telescopes and the integration of sensors to measure the performance characteristics of this system during operation.

The Naval Research Laboratory and Composite Mirror Applications (CMA) have been working together for several years on the development of Carbon Fiber Reinforced Polymer (CFRP) optics and telescopes. We have documented the potential advantages of this technology in several other publications, including structural, thermal and weight advantages over traditional steel and glass optical systems. In this paper we present results of a battery of optical tests done on various CFRP replicated mirrors. Our goal is to demonstrate not only the optical quality of such mirrors but also their reproducibility and stability. We show test results on a sample of four mirrors. We performed extensive optical tests and also stability and repeatability tests. These tests are geared towards proving the use of this technology for a variety of optical applications including use in our CFRP telescopes.

Presented are results of a fabrication program to produce the Ring Imaging Cherenkov, RICH, mirror for the Alpha Magnetic Spectrometer, AMS-02, which is to be placed on the International Space Station. Composite Mirror Applications, Inc., CMA, in Tucson AZ was contracted by Carlo Gavazzi Space, CGS, to produce a conical mirror 1.3m diameter 0.5m in height, from high modulus carbon fiber, flight qualified composite materials, having an optical surface on the inside of the cone. The flight model mirror was completed to specification, yielding nearly 2m2 of replicated optical surface area and weighs 8 kg. CMA measured the surface roughness and slope errors and the mirror dimensions were measured using a CMM at The University of Arizona’s Instrument Shop. The results show the mirror meets conformance to the required specifications. The RICH mirror is currently undergoing flight testing and integration.

The design, manufacture and characterization of lightweight carbon-fiber spherical converging mirrors for the RICH 1 Cherenkov detector of the LHCb experiment at CERN are described. The mirrors need to be lightweight to minimize the material for traversing particles and fluorocarbon-compatible to avoid degradation in the C4 F10 gas radiator of RICH 1. Four large-sized carbon-fiber mirrors covering a total surface area of ∼2m 2 were installed in RICH 1 in July 2007. The mirrors have a radius of curvature of ∼2700 mm, a high reflectivity of ∼90% in the 200-600 nm wavelength band, a low areal density of ∼5 kg/m2 equivalent to ∼1.2% of a radiation length. Results of the radiation and fluorocarbon testing of the mirror prototypes are also reported.

Present space-based optical imaging sensors are expensive. Launch costs are dictated by weight and size, and system design must take into account the low fault tolerance of a system that cannot be readily accessed once deployed. We describe the design and first prototype of the space-based infrared imaging inter- ferometer (SIRII) that aims to mitigate several aspects of the cost challenge. SIRII is a six-element Fizeau inter- ferometer intended to operate in the short-wave and midwave IR spectral regions over a 6 × 6 mrad field of view. The volume is smaller by a factor of three than a filled-aperture telescope with equivalent resolving power. The structure and primary optics are fabricated from light-weight space-qualified carbon fiber reinforced polymer; they are easy to replicate and inexpensive. The design is intended to permit one-time alignment during assembly, with no need for further adjustment once on orbit. A three-element prototype of the SIRII imager has been constructed with a unit telescope primary mirror diameter of 165 mm and edge-to-edge baseline of 540 mm. The optics, structure, and interferometric signal processing principles draw on experience developed in ground-based astronomical applications designed to yield the highest sensitivity and resolution with cost- effective optical solutions. The initial motivation for the development of SIRII was the long-term collection of technical intelligence from geosynchronous orbit, but the scalable nature of the design will likely make it suitable for a range of IR imaging scenarios.