Monitoring and Tracking Orbital Debris: Strategies and Technologies
Introduction
The increasing volume of space debris orbiting Earth poses significant challenges to both manned and unmanned spacecraft. Two primary aspects are critical concerns: avoidance and continuous tracking.
Avoiding and Cataloging Orbital Debris
When it comes to avoiding orbital debris, traditional methods like LIDAR or millimetric radar can provide valuable data for identifying larger pieces. However, these methods may fail to detect smaller debris. An innovative solution involves the use of micrometric radar within a narrow and specific path, creating a tube-shaped detection zone
This system, coupled with shielding against kinetic impacts, can significantly enhance the safety of spacecraft. Another key aspect is cataloging all orbital debris. While it is theoretically possible to catalog every piece, the complexity and the entropy of the system make it impractical. Instead, we recommend a hybrid approach where active spacecraft are continuously tracked using GNSS and passive debris are regularly monitored with advanced radar systems.
Advanced Tracking Systems
To effectively track space debris, several advanced tracking systems have been developed and deployed. One notable system is the U.S. S-band radar tracking system, which has been recently deployed in the Pacific Ocean region. This system provides high-resolution tracking for currently operational spacecraft.
New Tracking Facilities: Additionally, a new S-band radar tracking facility in Australia is being discussed. This facility, set to replace the earlier VHF-band radar system in Texas and Arizona (known as "the Fence"), offers ten times greater tracking sensitivity, making it highly effective for detailed tracking of small debris objects.
Moreover, the DLR-funded GESTRA facility, which is also known as the TIRA system, uses a new phased-array antenna design to track debris elements as small as 1 centimeter in size. This is particularly important for low Earth orbit and the protozone's object tracking. Currently, around 22,000 objects are being tracked, with approximately 20,000 being defunct space objects without active control systems, creating a challenging landscape for space traffic management.
Challenges and Limitations
The effectiveness of these tracking systems is limited by several factors. Hypersonic vehicles and scramjet-type weapon systems pose unique challenges, as national air traffic control agencies cannot exercise exclusive traffic control over these vehicles in the protozone. This highlights the need for a more comprehensive international approach to space traffic management.
Despite these challenges, the development and deployment of advanced tracking systems represent significant strides in mitigating the risks associated with orbital debris. By investing in continuous monitoring and improving the accuracy of tracking systems, we can enhance the safety and sustainability of space operations.
Conclusion
Space debris is a growing concern that requires a multi-pronged approach to address. Effective avoidance measures and continuous tracking using advanced radar systems are crucial. International cooperation and the development of new technologies will be essential in ensuring the long-term sustainability of space debris management and safety.