This dance of metal and circuitry, performed with pinpoint accuracy in the harsh vacuum of space, is made possible by a device smaller than a shoebox: Terma's Star Tracker.

"What the Star Tracker does is that it tells the onboard computer of the satellite, 'Which direction am I looking?'" explains Dan D. V. Bhanderi, senior product and project manager at Terma Space. Behind this deceptively simple statement hides the complexity and critical importance of star trackers in modern space missions.

The Terma Star Trackers comes out of an extensive portfolio of sensor systems, and constitutes the primary technology for space navigation. The trackers play a pivotal role in determining a spacecraft's orientation by capturing images of star fields and comparing them to an onboard star catalog, these sophisticated devices provide crucial attitude information.

This data is essential for ensuring that communication antennas point towards Earth, solar panels face the Sun, and scientific instruments focus on their intended targets.

The Star Tracker Evolution of Excellence

Terma's Star Tracker story began with the HE-5AS, a legacy system that set the standard for reliability in space. This robust technology found its place on several high-profile missions, including ESA's CryoSat-2 , which continues to provide valuable data on Earth's ice sheets and sea levels.

Building on this solid foundation, Terma developed the T1 and T3 Star Trackers, representing a quantum leap in performance and versatility. The T1, designed for missions demanding the highest reliability, can withstand the harsh radiation environment of geostationary orbit for 15 years or more. Its counterpart, the T3, caters to the growing New Space market, offering a compact solution for smaller satellites in low Earth orbit.

- The T3 was made exactly for the commercial space missions. We thought, how can we make the technology readily available at a much lower price? How can we make it commercial? So, we reused the camera, but changed the specs that were specifically designed for ESA and NASA missions—e.g. the extensive documentation requirements—and have arrived at basically a COTS star tracker of ultrahigh quality, Bhanderi explains.

These advancements didn't happen overnight. They are the result of years of research, development, and real-world experience gained from numerous successful space missions. Terma's commitment to excellence has positioned its Star Trackers as critical components in satellites ranging from Earth observation to deep space exploration.

Star Tracker T3

Technical Innovations: Miniaturization, Optics, and Thermal Stability

At the heart of Terma's Star Tracker evolution lies a series of groundbreaking technical innovations. One of the most significant advancements is in miniaturization. The T3 Star Tracker, for instance, packs powerful performance into a remarkably compact form factor. This reduction in size and weight is crucial for modern satellites, where every gram counts.

The optical systems in Terma's Star Trackers represent another leap forward. Utilizing rad-hard aspherical optics, these devices achieve exceptional accuracy without compromising durability. The T1 Star Tracker boasts an impressive accuracy of 3.6 arc seconds, enabling it to detect changes in orientation as minute as the height of a euro coin viewed from a distance of one kilometer.

Perhaps one of the most remarkable features of Terma's Star Trackers is their thermal stability, achieved without the need for active cooling. This is a significant departure from traditional designs, which often rely on power-hungry cooling systems to maintain optimal performance. Terma's innovative approach not only reduces power consumption but also allows for a trouble-free operation in an extreme temperature range, compared to traditional star trackers that need cooling units fitted.

From Innovation to Impact: Real-World Benefits

The technical advancements in Terma's Star Trackers translate directly into tangible benefits for space missions. The improved reliability and longevity of these devices are particularly crucial in the unforgiving environment of space, where repairs are impossible and replacements are prohibitively expensive.

Consider the T1 Star Tracker's ability to operate in geostationary orbit for up to 15 years. This extended lifespan ensures that satellites can complete their missions without the need for premature replacement, maximizing the return on investment for space agencies and commercial operators alike.

Star Tracker T1

Moreover, the cost-effectiveness of Terma's Star Trackers extends beyond their longevity. Our innovative design and production processes have enabled the scaling of manufacturing, allowing for significant production volumes.  

- Last year, we delivered more than 100 of these small ones, Bhanderi  notes.

This scalability not only reduces costs but also ensures a steady supply to meet the growing demands of the space industry.

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Divorce by Design for Greater Flexibility

Terma's Star Trackers offer a unique advantage in their flexible implementation options. Beyond the traditional integrated solution, space-companies can opt for what's known as a hosted solution.

- Rather than buying this rather expensive computer, you can just take the software and put it on your own computer onboard the satellite, Bhanderi explains.

This ‘divorce-by-design’ approach provides customers with the baffle, camera, and software library for integration with their existing systems.

- Once you have the software, you can reuse it on multiple cameras. You don't need to buy the software for each camera," notes Bhanderi.

This versatility obviously reduces costs but also provides greater flexibility in satellite design, particularly valuable for constellation projects or missions where space and weight are at a premium. 

Charting the Future: Ongoing Research and Development

Terma's commitment to innovation doesn't stop with its current product line. The company is actively engaged in research and development to push the boundaries of star tracker technology even further. One particularly exciting area of exploration is the application of artificial intelligence to enhance star tracker performance.

By incorporating AI algorithms, Terma aims to improve the accuracy of its star trackers beyond what is currently possible with traditional methods. This could potentially enable even more precise attitude determination, opening up new possibilities for space missions that require ultra-high accuracy.

The company is also focusing on further improving the scalability of its production processes. As the demand for star trackers continues to grow, particularly in the New Space market, Terma working intensely to meet this demand without compromising on quality or performance.

Ready for Next Generation of Space Missions

As we stand on the brink of a new era in space exploration, the importance of reliable, accurate, and efficient navigation systems cannot be overstated. Terma's Star Trackers, with their cutting-edge technology and proven track record, are playing a crucial role in enabling increasingly ambitious space missions.

From Earth observation satellites, that help us understand and protect our planet, to deep space probes venturing into the unknown, Terma's Star Trackers are there, quietly and reliably ensuring that these incredible machines know precisely where they are and where they're pointing.

As we look to the future, one thing is clear: with companies like Terma continuing to push the boundaries of what's possible, the stars are not just our guides—they're our destination. And with each innovation in star tracker technology, that destination grows ever closer.