Since the first satellite launch in 1957, Earth’s orbital environment has become increasingly crowded with resident space objects (RSOs), including operational spacecraft, communication satellites and debris from past missions. As our reliance on space infrastructure grows, so do the risks associated with space debris, as high-velocity collisions become more likely, resulting in even more debris. If left unchecked, this problem could render regions of space unusable, making Space Situational Awareness (SSA) one of the most important undertakings of this century.

A key component of SSA is detecting and tracking RSOs to predict and avoid collisions with active satellites. Radar systems are vital for tracking objects in Low Earth Orbit (LEO), as they operate 24/7 and are not dependent, to an extent, on weather or lighting conditions.

Ground-based radar systems provide essential data on the position, velocity and trajectory of space debris, which can be used to model and predict future paths. Radar systems transmit signals that reflect off objects, allowing researchers to calculate their speed and location based on the properties of the ‘echo’ signal compared to the original transmission.

In collaboration with the Italian National Institute for Astrophysics (INAF), researchers at the Institute of Space Sciences and Astronomy (ISSA), University of Malta, have developed a detection system for the BIstatic RAdar for LEo Survey (BIRALES) radar.

With a transmitter in Sardinia and the Northern Cross radio telescope in Medicina acting as the receiver, BIRALES detects objects as small as 10cm and as far as 1,000km away, and has been operational since 2018. The detector developed by Denis Cutajar uses an algorithm to successfully and reliably detect debris echoes in real time, such that their information can be logged and analysed by researchers.

Ground-based radar systems provide essential data on the position, velocity and trajectory of space debris, which can be used to model and predict future paths

Recent plans for an expansion to the BIRALES infrastructure will result in a huge data increase, necessitating an upgrade to the current detector. To mitigate this, the SMARTIES project at the University of Malta aims to use the power of artificial intelligence (AI) to develop a new algorithm to replace the current detector. This project, led by Alessio Magro, uses the current pipeline as a benchmark on which to train neural networks by curating a large collection of observational data labelled by the detector.

Results thus far have been promising, and once the model is ready, it will be integrated into the BIRALES pipeline to ensure that real-time tracking of space debris remains feasible.

SSA programmes are vital in making sure all future missions are safe from catastrophic collisions, and it all starts with keeping track of all the trash we’ve left in space, a few echoes at a time.

The Space Monitoring using AI-based Radar Techniques: Investigating Echoes and Streaks (SMARTIES) Project at the Institute of Space Sciences and Astronomy (ISSA), University of Malta, is financed by the Xjenza Malta Space Upstream Programme.

Miguel Zammit is a PhD researcher at the Institute of Space Science and Astronomy, University of Malta, and a research support officer working on the SMARTIES project.

Sound Bites

•         Researchers at CU Boulder discovered a new link between weather on Earth and weather in space. They used satellite data to show that lightning storms on our planet can knock especially high-energy electrons out of the inner radiation belt – a region of space filled with charged particles that surrounds Earth.

•         Researchers have invented a technique that enables low-Earth-orbit satellite antennas to manage signals for multiple users at once, slashing costs and simplifying designs for communication satellites. The strategy builds on a common technique to split transmissions from a single antenna array into multiple beams without requiring additional hardware.

For more soundbites, listen to Radio Mocha www.fb.com/RadioMochaMalta/.

DID YOU KNOW?

•         There are 1.4 million kilometres of telecommunication cables on the seafloor worldwide.

•         If laid end to end, these cables would span the diameter of the sun.

•         The cables are responsible for transferring 99 per cent of all the digital data around the world.

•         Despite the cables being exposed to various extreme environmental events, the biggest cause of damage is not natural, but human.

•         Most faults relate to activities like dropping of anchors or dragging of trawler boat nets which snag on the cables.

For more trivia, see: www.um.edu.mt/think.