The most common stratoyager, which serves the army and most other uniformed services. Guaridans carry the colors of System Police, border guards, customs or ordinary police and planetary militias. Quite often the Guardians are equipped with personal protection companies, private companies and corporations.

The first STF-150 models were manufactured by Nova in 2173 to replace the already worn F-100j Sentinel Mk IV. Compared to its predecessor, the Guardian was smaller and lighter, making it possible to use more economical engine solutions. The STF-150 is equipped with a single pulse-gravity motor Nova Aero SV-200, allowing it to achieve an acceleration of 25g. Later, the model 150c replaced the power unit on the Nova Aero SV-210b equipped with overload system, which allowed to temporarily increase the acceleration to 40g. It was quite risky because the Guardian’s frame construction was calculated at overloads of up to 33g.

Due to the single main engine, a special nozzle was developed to facilitate the control of the gravitational field. To compensate for the “heavy rear” effect, the STF-150 has received quite long, as for the stratoyager, wings with gravity-assisted coils. By using the most advanced gravity buffering systems, Guardian was able to compensate for acceleration and reduce the perceptible force by 20g. The STF-150 was the first unit equipped with such powerful overload buffers, the Rols Royce Gravmaster.

In the planet atmosphe Guardian seems over-equiped with the Rols Royce GVTE-2600 anti-gravity unit, which exceeds the total payload, but excessive power allows for greater maneuverability and stability.

The fighter was also equipped with innovative, at that time, laser grades to reduce unit energy consumption while increasing rate of fire. Two FDA LC325s are installed in the STF-150 each. In the first model STF-150 was working side by side, under the hull, along the cockpit but in later versions, starting with the STF-150c, they were placed on the wings together next to the cockpit, eliminating the bow sense distortions that had the tendency to cause innovative action.

By the year 2230, nearly 40,000 Guardian units were produced. You can sometimes encounter a two-seater training version of 150c / tr and a scout model 150sr with long range scanners. Currently, the latest basic model carries the number STF-151a and is equipped with more sensory systems and newer cockpit equipment.