James Allworth, HEO; Stuart Bartlett, HEO; Samantha Kirkwood, HEO; Karla Vincent, HEO; Hannah Dawe, HEO UK; Jack Sines, HEO UK; Toby Harris, HEO UK; Hiranya Jayakody, HEO; William Crowe, HEO
Keywords: NEI, satellite characterization, resolved imagery, space-based assets
Abstract:
Resident Space Object (RSO) identification and characterisation is essential for various space operations, including attribution, accurate tracking and propagation as well as capability and threat assessment to avoid operational surprise. Traditional satellite characterisation methods have predominantly relied on the use of ground-based observations, both non-resolved optical and radar, to estimate information about the size, shape, attitude, and material properties of unknown objects. However, these methods are often only able to achieve partial characterisation and typically result in large uncertainties with multiple possible solutions, limiting the effectiveness of this analysis for the applications outlined above. Recent advancements in the use of space-based assets to obtain resolved imagery through flyby imaging introduces a significant enhancement in capability for rapid RSO characterisation. This paper provides an overview of a novel approach to rapid RSO characterisation through the utilisation of flyby Non-Earth Imagery (NEI) developed by HEO.
NEI is the use of space-based telescopes and sensors to perform resolved imagery of other objects in space. The term flyby refers to the utilisation of passive imaging opportunities (non-intrusive) where the orbit of the imaging sensor is not actively adjusted in order to create a favourable imaging opportunity with the target object. This approach has several challenges: objects in space are far apart from one another, are typically moving with very high relative velocity and imaging opportunities occur with a range of different lighting conditions. To perform flyby NEI successfully and within a sensible time-scale, multiple imaging platforms on different orbital planes are required with high resolution telescopes and a suitable automated infrastructure. HEO achieves this by leveraging existing Earth Observation platforms, supplemented by purpose built NEI telescopes in regions with low coverage, to perform high-cadence, resolved images of RSOs in space.
The recent rise in accessibility of space through both national and commercial launch providers has led to a considerable increase in on-orbit objects within the last five years. As more organisations attempt to utilise the benefits of space for scientific, commercial, and military purposes it is expected that this trend will continue. This rapid increase in deployed satellites, particularly through rideshare missions where 10s of satellites can be deployed from a single launch, has resulted in traditional identification and characterisation methods relying on ground-based radar and non-resolved optical observations becoming overwhelmed. As of August 2024, there are currently more than 700 unidentified and uncharacterised objects in the space-track catalogue maintained by the 18th Space Defense Squadron, a large proportion of which have come from foreign launches, with this number increasing significantly over the past two years.
Flyby NEI provides a viable alternative to traditional characterisation techniques and a potential solution to reduce the number of unidentified RSOs. Unlike ground-based methods, flyby NEI produces resolved imagery of target objects enabling specific components, such as solar panels, thrusters, antennas and payloads on the target object to be identified and analysed. This information enables RSOs to be quickly identified and characterised as active payloads, rocket bodies and debris, as well as confirmation of satellite class based on comparison with known satellite types. For objects that do not match a known satellite bus type or class, HEO performs further focused imaging on the target in order to produce a 3D model and make an assessment of its capability. In this paper, an overview of the flyby NEI methodology implemented by HEO will be provided as well as an analysis on how resolved imagery data can be utilised to identify and characterise unknown RSOs, with reference to specific real-world examples, which have been successfully characterised by HEO. Additionally, a case study on the Chinese space plane launch in 2023 will also be included to demonstrate how flyby NEI can be used to rapidly provide characteristic information on unknown objects from a foreign launch, where threat assessment is required in a timely manner.
Date of Conference: September 17-20, 2024
Track: Space-Based Assets