The Sync-Sat Calculator

Sync-Sat Calculator front 1

This calculator and an associated 33 page report was prepared for NASA in 1967.  It is concerned with the mathematical problems associated with aligning orbiting satellites with earth stations.

The Earth’s first artificial satellite, Sputnik 1, had been launched in 1957. There then followed a period of successful launches by the USSR and humiliating failures by the USA.

Things improved and in 1960 TIROS 1 became the first satellite to transmit television images from space. In 1962 TELSTAR 1 started  relaying  television, telephone and high-speed data communications. In 1964 SYNCOM 3 became the first communications satellite in geostationary orbit. By 1967 there were a considerable number of commercial satellites either in orbit or planned and it was clear that satellites were going to have a big effect on all kinds of communications.

Sync-Sat Calculator back  2

The Sync-Sat Calculator was designed to solve problems concerning the geometric relations between synchronous, near equatorial, satellites and ground stations. These problems were important to the operators of commercial, military and other satellites.

The calculator has four parts, each requiring independent settings.

Parts 1 and 2 provide parameters relevant to narrow beams and small areas.

Part 3 was used for calculating the field of view of satellite placed at various longitudes.

Part 4 concerns the problems of tracking several earth stations from a single satellite. This problem would, for example, concern commercial satellite operators who wanted to provide a service targeted at ground stations in specific cities.

Sync-Sat manual 2

The calculator was produced by Perrygraf. It is 10 inches [255 mm] by 4 inches [103 mm] and is made of plastic.

For posts about other calculators from the early space age click on the Space Age Calculators category on the right.

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