Description: Optical Physics Company (OPC) proposes to adapt the precision star tracker it is currently developing under several DoD contracts for deep space lasercom beam pointing applications. The advantages of using an interferometric star tracker for beam pointing are numerous, these include the following: 1. Celestial reference based beam pointing eliminates need for having a ground based beacon for return beam pointing. 2. Precision star tracker can be part of the spacecraft attitude control subsystem, thus allowing a single high performance instrument to support both attitude control and lasercom beam pointing functions. 3. By allowing the lasercom system to point with a faint beacon and/or weak stars, the same lasercom system architecture can be employed for both deep space flight terminal and the near-Earth terminals operational from near orbit to very deep space mission. The Phase I effort will be a firm foundation for Phase II: We will not only have developed the concept and the design of the Precision Pointing Platform but also validated the functionality and performance using detailed simulation that includes models of the active isolators and the jitter environment with high fidelity. The simulation will use a realistic star background. Furthermore, Phase I work will also produce a pointing error budget that takes into consideration effects of SNR, unrejected platform jitter, alignment errors and optical fabrication errors.

Benefits: The most immediate application of this technology is in deep space optical communications with the main customer in this area being NASA. NASA Draft Communication and Navigation Systems Roadmap Technology Area 05 dated November 2010 states in reference to optical communications that "longer term, reliance on beacons should be eliminated." Our technology offers the ability to communicate from a near Earth or deep space (up to 40 AU) spacecraft platform using a narrow beam aimed precisely at a beaconless receiver. We can consider both near Earth and deep space applications for the proposed technology. For applications in deep space ranges (up to 40 AU- which is the radius of the solar system), we can name the JPL project called deep-space optical terminals (DOT) as our primary customer at this time. This project was initiated in 2009. DOT involves concept and design of terminals that can handle higher data rates with lower mass and power than the Mars Laser Communication Demonstration (MLCD). OPC has also been funded recently for a study by JPL to investigate if its interferometric star tracker can be used for a spinning spacecraft. The study findings have shown the feasibility of adapting the interferometric tracker to provide accurate attitude information for a rapidly spinning spacecraft.

Application most relevant to this project is the use of star trackers for spacecraft. OPC is building a cubesat star tracker at this time to deliver to a DOD customer. The performance is power dependent - ranging from sub arcsecond to 2 arcsecond accuracy. The package is small - 250 cc in volume. Another visible band star tracker application was proposed to the Navy recently under the SBIR program. This proposal has been selected for award. The application involves space situational awareness, specifically to develop, build and deliver a version of the interferometric tracker capable of detecting and tracking dim objects. Another application is GPS denied navigation which has increasingly become a more acute need in the past few years. Customers are GPS denied navigation systems include virtually the whole armed forces. Our approach is primarily tailored to airborne platforms such as fighter aircraft, ground attack aircraft, next generation bomber, Tier II and Tier II+ UAVs, airborne early warning and control aircraft, ICBMs, and missiles including hypersonic missiles. OPC is currently funded under Navy RIF to build and flight test a stellar inertial navigation system prototype.