Summary: Austrian researchers have dramatically improved the accuracy of tracking space debris from kilometers to just centimeters by combining satellite laser ranging with advanced gravity field measurements. This breakthrough, developed at TU Graz, enables better prediction of orbital paths for both active satellites and space debris, significantly improving safety in orbit. The technology has been made freely available through open-source software.
Journal: Journal of Geodesy, September 13, 2024, DOI: 10.1007/s00190-024-01888-5
Reading time: 4 minutes
A Growing Problem Above Earth
High above our planet, a dangerous scene is unfolding. Approximately 40,000 pieces of space debris larger than ten centimeters are orbiting Earth, along with roughly one million pieces larger than a centimeter. These objects hurtle through space at about 30,000 kilometers per hour, creating a serious hazard for satellites and spacecraft.
Until now, tracking these objects has been imprecise, with predictions accurate only to within several kilometers. But researchers at TU Graz have developed a solution that dramatically improves our ability to track this orbital debris.
Laser Precision Meets Gravity Mapping
The breakthrough combines two powerful tools: satellite laser ranging (SLR) and gravity field measurements. The system uses a network of stations that point lasers at satellites equipped with special reflectors. By measuring the travel time of the laser light, scientists can pinpoint satellite positions with unprecedented accuracy.
“If you combine SLR with the other satellite measurement methods, the gravity field can be calculated much more accurately, as you can precisely resolve all wavelengths of the gravity field,” explains Sandro Krauss from the Institute of Geodesy at TU Graz.
From Kilometers to Centimeters
The improvement in tracking accuracy is remarkable. The research team developed force models that can determine satellite or debris positions to within about 100 meters – a massive improvement over previous kilometer-range accuracies.
“For orbit prediction, we have to model all the forces on the satellites,” says Torsten Mayer-Gürr from the Institute of Geodesy. “This also includes the Earth’s gravitational force, which is influenced by the presence of masses such as water.”
Open Source for Global Safety
In an unusual move for such advanced technology, the researchers have made their GROOPS software freely available via GitHub. “As far as we know, we are the only ones to offer such a comprehensive package for gravity field determination, orbit determination and SLR processing free of charge. This open source access has the advantage for us that we get feedback very quickly if something needs to be improved,” notes Mayer-Gürr.
Glossary
- Satellite Laser Ranging (SLR): A technique using laser measurements to precisely determine satellite positions
- Space debris: Non-functional artificial objects orbiting Earth
- Gravitational field: The area of influence of Earth’s gravity that affects orbital paths
- Force models: Mathematical representations of forces affecting satellite orbits
Quiz
- Q: How many pieces of space debris larger than 10cm are currently orbiting Earth?
A: Approximately 40,000 - Q: At what speed do space debris objects typically travel?
A: Around 30,000 km/h - Q: How accurate is the new system at determining satellite positions?
A: To within about 100 meters - Q: Where has the research team made their software available?
A: Via GitHub as open-source software
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