Andrew Abraham, Lockheed Martin; Oliver Schultz, Lockheed Martin Space
Keywords: cooperative tracking, GPS Transponder, beacon, Space Traffic Managment
Abstract:
Cooperative Tracking Aid for Space Domain Awareness
Since the dawn of the space age the ability to track Resident Space Objects (RSOs) has been of paramount interest. Throughout the second half of the previous century the baseline tracking methodology relied upon governments and militaries tracking RSOs via state-owned and operated sensors consisting primarily of ground-based radar and electrooptical telescopes. While this methodology sufficed for decades, recent changes in the space environment warrant a reconsideration of the sufficiency of traditional approaches to Space Domain Awareness (SDA). Recently, near-Earth-space has become increasingly congested and contested. Proliferated constellations are now commonplace and have increased the number of active satellites by an order of magnitude. Many of these satellites conduct low-thrust, frequent, and sometimes autonomous maneuvers which break the traditional assumptions of Kepler orbits that undergird the traditional SDA methods mentioned earlier. Not to mention multi-satellite deployments and other non-traditional operations that make it a struggle to prevent cross-tagging, positively identify a specific satellite, and keep custody of all satellites in space.
Other environments, such as the aviation (ADS-B) and maritime (AIS) domains, have dealt with similar challenges and have evolved over the decades towards a cooperative tracking system that offers many advantages over a non-cooperative one. Positive ID, increased density of safely operating vehicles, and improved operational efficiencies are all benefits realized with a cooperative approach in these domains. Unfortunately there is no parallel for cooperative tracking in the space domain. It is the intent of this work to prove that a similar approach, significantly adapted for the unique features of the space domain, would work within a low Size, Weight, Power, and Cost (SWaP-C) constraint.
In the aviation domain an unpowered craft, with limited exceptions, falls out of the sky and is no longer operating within that domain. The space domain is very different as an unpowered (dead) satellite remains on its orbital trajectory just the same as a powered one. Therefore it is imperative that any cooperative tracking device retains a self-powered mode that permits independent operation from the host satellite in the even of that satellite’s failure. This is accomplished through the use of photovoltaic cells, a small battery, and appropriate circuitry and CONOPS that permits operation at a very modest power budget. The device will have a GPS/GNSS receiver onboard to calculate position at a given timestamp and a low-power, low data rate radio that can transmit this position data and identifier number to an ultra-low-cost, Internet-of-Things (IoT) ground network. Once the data is on the ground it can be fed into orbit determination software to formulate highly precise orbits (covariance that is an order-of magnitude better than non-cooperative methods), can easily distinguish (positive ID) between objects in multi-satellite deployments, and can trigger follow-on analysis if critical thresholds are met. For example: maneuver processing, RPO activities, reentry events, and other scenarios of interest can all be discovered in near-real-time due to the frequency and high-quality of the observation data (GPS fixes). For such an approach to become universally accepted it is important to minimize the SWaP-C as much as possible. In this work we have created a prototype that is about the size of a deck of playing cards, weighs a few hundred grams, and is at a cost that would be appealing to everyone including start-up businesses and hobbyists.
This presentation will illustrate Lockheed Martin’s modeling and simulation of a cooperative tracking system concept as well as provide an overview of a working prototype from both a hardware, software, and CONOPS perspective.
Date of Conference: September 19-22, 2023
Track: Space Domain Awareness