Research News: Space junk threatening satellites? Space traffic? Litter in Space?
Check out some of our latest work in space surveillance, as summarised by PhD student Gemma Cook, who is working alongside Dstl.
What’s new
We have recently collaborated with Cubica Technology to contribute towards a Dstl led, space domain awareness (SDA) project, ‘Phantom Echoes 2’ to collect data from a rendezvous between two active satellites in GEO using the Liverpool Telescope (LT).
The research
Phantom Echoes was an SDA experiment to observe the docking between the communications satellite Intelsat 10-02 and the satellite servicing spacecraft, Mission Extension Vehicle-2 (MEV-2), using non-traditional space situational awareness (SSA) sensors. During this project a successful sensor management pipeline was developed to task the LT, a fully autonomous astronomical telescope based in La Palma, Canary Islands, to detect MEV-2 as it manoeuvred towards Intelsat 10-02. This was achieved by the forward propagation of a TLE (with some uncertainty) and then maximising the probability of detection within a fixed field of view. Due to the irregular thrust pattern of MEV-2 and its small size, accurate localisation and future predictions are more challenging than for larger satellites in stable orbits as current motion estimates quickly become inaccurate, resulting in more uncertainty with time.
Why it matters
Due to the increasing accumulation of objects in Earth’s orbit, from both active satellites and orbital debris (e.g., non-functional spacecraft, rocket upper stages, mission equipment), maintaining accurate knowledge of the space environment is an important domain in SSA. SSA aims to provide a complete and accurate portrayal of the objects in Earth’s orbit, the space environment and threats to life or assets from man-made space objects in events such as re-entries and in-orbit explosions or collisions. The ability to accurately track orbital objects is paramount in maintaining a sustainable space environment, by predicting and preventing collisions, performing safe manoeuvres, active debris removal and extending the lifetime of current satellites. The utilisation of current sensors, and the collaboration between an international community of defence space scientists has provided a range of optical and radio frequency measurements to be used to enhance the performance of individual independent systems.
We’re thinking
With a rich catalogue of data describing the sophisticated rendezvous between the two spacecrafts we aim to test and further develop the statistical tracking algorithms currently under development by the group and to compare the performance with current state of the art tracking algorithms using Dstl’s open-source tracking framework Stone Soup. By fusing data from different sources, we can utilise information otherwise unavailable due to missed detections, poor visibility or the limited availability of sensors. Combining tracking algorithms with sophisticated sensor management tools could allow automated tracking for similar advanced missions in the future.
Author: Gemma Cook, PhD Researcher
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