Sun sensors have been used in practically all spacecraft from the first satellites. Their design and operational principles are well developed. However, the demand for them is prompting developers and manufacturers to improve the existing devices. The improvements are aimed at increasing their reliability and lifetime, and decreasing their weight and cost. New manufacturing technologies as well as original schemes are being implemented.

The proposed FSS incorporates new technical and technological ideas, which make it attractive to potential users. The main FSS technical parameters are listed in Table.

The FSS is a static two-coordinate device using an original linear multipixel photosensor (number of pixels 1024). All the electronic modules have built-in redundancy.

An algorithm for computing the Sun image center of gravity has been developed for the sensor, and it can be implemented in hardware. The hardware implementation in special integrated circuits (ASIC) makes it possible to process the photosensor information in the real time mode and decrease the FSS update time to 6 ms.

The small update time reduces the average power consumption, and the low average power consumption lessens the requirements to the mounting plane thermal stabilization system. The small update time makes it possible to obtain the measurement information more rapidly and thus correct the spacecraft attitude faster. Besides, the hardware implementation of the image center of gravity computation algorithm dispenses with memory chips, which are a drawback of space equipment operating under exposure to radiation.

Ceramic materials give the case a longterm stability and, consequently, assure stable and accurate measurement results throughout the lifetime of the device.

The use of a special linear photosensor, manufactured by a bipolar technology rather than the CDD technology, is a prerequisite for solving the problem of embodying the entire device in a single integrated circuit, which further increases reliability, and decreases weight, size, and cost.

The multipurpose FSS design allows for modifications with fields of view of up to ±90° x ±90° for any spacecraft.

The FSS, like the EHS, is superior to its closest analogs in its parameters: weight, lifetime, reliability, and costs.

The FSS costs considerably less than do existing devices and has equal and superior technical parameters. In serial production its cost will not exceed $60,000. Its low weight means lower costs of launching into orbit. Its reliability will result in low insurance costs. And its long lifetime enables spacecraft to be used in orbit for a long time, recouping their cost and yielding a profit.

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