Feasibility of a National Space Debris Monitoring Center in Brazil: Site Selection and Sensor Technology Assessment

The sky above us is no longer empty. Since the first human-made object was launched into orbit in 1957, the space around Earth has become a crowded highway of satellites, spent rocket stages, and countless fragments of metal and paint. These objects, collectively known as space debris, travel at speeds so high that even a tiny speck can strike a satellite with the force of a small explosion. When a satellite breaks apart, it creates a cloud of new debris, which in turn increases the chance of further collisions, a dangerous cycle that could eventually make certain orbits unusable for future missions. To keep space travel safe, nations with advanced space programs operate networks of sensors to track these objects, predicting their paths so that active satellites can move out of the way. This practice, known as space situational awareness, is a critical safety measure, but for many countries, including Brazil, the ability to see and track this orbital traffic relies entirely on data provided by other nations.

A new study by Luis Fellipe Alves de Oliveira from the University of Brasília asks a straightforward but vital question: could Brazil build its own center to monitor this debris, and if so, where should it be built and what tools should it use? The research does not propose a finished construction plan but rather a feasibility assessment, weighing the pros and cons of different locations and technologies to see what would work best for a hypothetical national agency. The study focuses on the most dangerous size of debris: objects larger than 10 centimeters, which are big enough to destroy a satellite upon impact but small enough that they are difficult to track without dedicated equipment. By comparing five Brazilian cities that already have some connection to space activities and testing different types of sensors, the paper suggests a specific path forward that balances the country's scientific needs with its practical realities.

The researchers began by looking at how other nations handle this problem. Agencies in Europe, the United States, and Japan use a mix of powerful radar systems and optical telescopes to keep an eye on the sky. These systems are often located in remote areas with clear skies and low light pollution, or they are hosted by major universities that can provide the necessary technical expertise and funding. In Brazil, the situation is different. While the country has launched satellites and operates tracking stations, it lacks a dedicated center that can independently generate its own data on space debris. Currently, Brazilian satellite operators must rely on foreign data to avoid collisions, a situation that leaves the nation dependent on the priorities and schedules of other countries. The study sets out to change this by defining what a Brazilian center would need to do and where it could best operate.

To find the right location, the team compared five cities: Alcântara and Natal in the north, São José dos Campos in the southeast, Cuiabá in the central-west, and the capital, Brasília. Each city offered a different mix of advantages and challenges. Alcântara and Natal sit near the equator, which is a strategic position for watching satellites that orbit close to the Earth's equator, but both are on the coast where salt spray and humidity can quickly corrode sensitive electronic equipment. São José dos Campos is the heart of Brazil's aerospace industry, with excellent roads, airports, and a concentration of experts, but its weather is often cloudy and rainy, and the city lights are so bright that they would blind any optical telescope trying to see the stars. Cuiabá has a dry climate and low light pollution, making it good for looking at the sky, but it is far from the major industrial centers and ports, making it difficult and expensive to bring in large equipment or specialized technicians.

Brasília emerged as the most balanced choice for the center's location. While it is far from the coast and suffers from the light pollution of a large city, it offers something the other locations cannot match: direct access to the government agencies that fund and regulate space activities, as well as the University of Brasília, which has the engineering programs and research labs needed to run the center. The city's climate has a long dry season with clear skies, which provides a good window for observation, even if the city lights would make it impossible to use optical telescopes effectively. The study suggests that the best solution is to place the center in Brasília and equip it with a technology that does not care about the weather or the city lights.

That technology is a monostatic radar. Unlike optical telescopes, which need a clear, dark sky to see the faint reflection of sunlight off a piece of debris, a radar sends out radio waves that bounce off objects and return to the receiver. This means the radar can track debris day or night, in rain or shine, and it is not affected by the glow of city lights. The researchers found that while radar systems are expensive to build and maintain, they are the only option that would allow a center in Brasília to operate continuously and reliably. The study explicitly rules out optical telescopes as the primary sensor for this specific location, noting that the light pollution in the capital would make them ineffective. It also considers more complex radar setups that use separate transmitters and receivers, but concludes that the added cost and logistical difficulty make them less suitable for a first national center than a single, powerful radar unit.

The final picture painted by the research is one of a practical, strategic compromise. A national space debris monitoring center in Brazil would not be built in the most remote, dark corner of the country where the sky is clearest, but rather in the political and academic heart of the nation, where the people and money to run it are most accessible. By choosing a radar system that works regardless of the weather or the time of day, the center could overcome the limitations of its urban setting. This approach mirrors successful models in other countries where universities host national tracking assets in partnership with the government. If established, such a center would allow Brazil to protect its own satellites without relying on foreign data, strengthen its role in global space safety, and train a new generation of engineers to manage the orbital environment. The study suggests that while the path forward requires significant investment and careful planning, the combination of Brasília's institutional strength and the all-weather capability of radar makes the project not just possible, but the most logical step for the country to take.