End for infrared fire watch: DLR satellite BIROS burned up in the atmosphere

In the world of satellite technology, ten years is considered half an eternity. This is especially true for compact, small artificial Earth satellites operating in the harsh environment of low Earth orbit. The era of the BIROS satellite ended on January 22, 2026. According to the German Aerospace Center (DLR), the "fire scout" developed by the DLR entered the denser layers of the Earth's atmosphere on that day and burned up completely. This marked the conclusion of a mission that set technological standards and made a decisive contribution to understanding thermal processes on our planet. The satellite was launched in India in mid-2016, in a joint mission with 19 other satellites.

BIROS – the name stands for Bispectral InfraRed Optical System – together with its almost identical twin TET-1, formed the backbone of the FireBIRD mission, according to the DLR. The goal was ambitious: to capture high-temperature events on the Earth's surface with a precision that conventional weather satellites often cannot achieve. The heart of the system was the highly sensitive HSRS infrared camera system. It operated with two different spectral bands in the mid and thermal infrared ranges, giving the orbiter a kind of thermal X-ray vision.

The special feature of this technology lay in its enormous dynamics, explains the DLR. While ordinary sensors often become "blind" or overloaded by extreme heat sources, BIROS could automatically adjust its measurement ranges. The system covered a temperature range from 300 to 1300 degrees Celsius. In practice, this meant that the satellite could accurately depict both a small fire in the undergrowth, only ten square meters in size, and massive lava flows of an active volcano in the same image. This ability to document the smallest hotspots alongside enormous fire sources without signal loss made BIROS a "unique" remote sensing tool for the DLR worldwide.

Global Fire Alarm Center

The scope of application was not limited to early forest fire detection. Researchers used BIROS data to analyze a variety of human and natural heat sources. These included burning ships on the oceans, industrial gas flares, chemical heat developments, or often difficult-to-locate underground smoldering coal seam fires. The "fire magnifying glass" thus functioned as a kind of global fire alarm center. It provided data that was of high value for both disaster control and climate research.

Behind the success of BIROS was a complex alliance of research institutes and medium-sized industries. The project was significantly driven forward at the DLR Institute for Optical Sensor Systems in Adlershof, Berlin. The spatial proximity to specialized companies such as Astro- und Feinwerktechnik, also located in Adlershof, was a decisive locational advantage, according to the research center.

Potential Further Developments

In this consortium, the DLR took over the system technology preliminary research. In parallel, industry supplied standardized components for the satellite bus, for example. This close integration between the expertise of the University of Würzburg, various other DLR institutes in Braunschweig, Göttingen, Oberpfaffenhofen, and Weilheim, specialized aerospace companies, and the ground station of the German Remote Sensing Data Center (DFD) in Neustrelitz has shown, according to those responsible: Germany is capable of independently realizing complex space missions over their entire life cycle.

Even though BIROS's hardware no longer exists, its technological legacy remains. The insights gained during the mission are to be directly incorporated into the development of the next generation of small satellites. Future missions could then capture the Earth in the wavelength ranges of four and ten micrometers with even greater detail. The era of specialized infrared Earth satellites is thus likely to gain real momentum through the "firebird." Furthermore, the mission's data archives will continue to provide scientists with information for years to come on how thermal hotspots are changing worldwide. This know-how appears more important than ever in view of increasing extreme weather events.

(syt)