Kevin Brannick, Raytheon Intelligence and Space; Scott Reed, Raytheon Intelligence and Space; Karen Galang, Raytheon Intelligence and Space
Keywords: Space Development Agency, space domain awareness, SDA, National Defense Space Architecture, NDSA, concept of operations, CONOPS, space situational awareness, SSA, resident space object, RSO, Space Surveillance Network, SSN, Tracking Layer, custody
Abstract:
The Space Development Agency (SDA) proposes a future National Defense Space Architecture (NDSA) that features multiple layers in low Earth orbit (LEO), each with a unique mission and a potentially large number of satellites. While these systems may be required to provide a particular military capability at all times, there will likely be periods when certain satellites and sensors are not needed for a constellation to reliably and accurately provide its primary service. These redundant space assets can perform a secondary mission such as observing Resident Space Objects (RSOs) at or near geosynchronous earth orbit (GEO), effectively augmenting the Space Surveillance Network (SSN) and enhancing space domain awareness. Leveraging these efficiencies could enhance the utility of a large, resilient space architecture and also reduce costs for the government to develop and field separate space situational awareness (SSA) capabilities. The NDSA includes a Tracking Layer with a primary mission to track and target advanced missile threats and provide critical indications and warning. This paper presents the operational benefits of adding a secondary SSA mission to this Tracking Layer. Just as evolving missile threats necessitate space-based observations of the Earth, evolving space threats demand improved and persistent SSA to facilitate space asset protection. Exploiting the mission architecture’s persistent access to RSO and missile observations, and the dual application of the same sensors, both the Tracking Layer and SSA missions could potentially yield a multi-mission system at reduced cost to the government with no noticeable degradation in primary mission service to the end-users.
A notional Tracking Layer could feature spacecraft equipped with optical and/or infrared sensors used for Earth-pointing observations. The same sensors can produce observations of space objects when pointed away from Earth and into deep space. This function could help maintain and update an existing space catalog of RSOs and even reveal the intent and characteristics of spacecraft based on their positioning and movement over time. This paper demonstrates the feasibility and practicality of using one common proliferated LEO (pLEO) space architecture for both purposes. We model both missions with one constellation representative of a notional Tracking Layer architecture. Each spacecraft features a passive electro-optical (EO) sensor modeled after Canada’s Sapphire satellite in LEO, which provides RSO observations to the SSN. Actual cataloged information of RSOs, including publically available ephemeris and object size parameters, enable simulations of RSO detections, yielding the quantity of space objects observed and revisit rates. We examine the quality of orbits determined from the aggregated RSO observations and assess the effectiveness of the space surveillance mission. We evaluate these metrics over several time periods of availability for the secondary mission and identify CONOPS that represent the different duty cycles, while ensuring that the primary mission requirements are not compromised, or at most have minimal impacts.
Date of Conference: September 15-18, 2020
Track: SSA/SDA