Quotulatiousness

July 10, 2012

Telstar’s 50th anniversary

Filed under: History, Space, Technology, USA — Tags: , , — Nicholas @ 09:47

Scott Van Wynsberghe in the National Post:

What followed Echo 1 was a space race within a space race, this one determining whether government or industry would send up the first active non-military communications satellite. In 1961, NASA awarded a contract for such a satellite to the company RCA, but Pierce and Bell Labs were undeterred. According to Calvin Tomkins, Bell Labs spent US$50-million (at early-1960s rates) for research and development and devoted about 700 of its personnel to the project.

The baby that was born of it all was a sphere weighing 170 pounds (77 kilograms), called Telstar 1. Going by specifications collected by Bill Yenne, an authority on U.S. spacecraft, Telstar 1 received signals at 6,390 megacycles, re-transmitted them at 4,170, and boasted of 600 voice channels and one channel for television.

Perched atop a Thor-Delta booster — paid for by Bell Labs but launched by NASA — Telstar 1 ascended on July 10, 1962. It did not go far, parking itself in an elliptical orbit less than 2,000 miles (3,220 kilometers) away. Within hours, Bell Labs arranged what was previously impossible — transatlantic television. As described by T.A. Heppenheimer, the ensuing video exchange humorously followed national stereotypes. The United States sent France and the U.K. taped material heavy on patriotic themes, the French responded with footage of actor Yves Montand and other cultural figures, and the British muddled about for a few days before getting things straight.

Humour aside, the achievement left the world stunned. In just the month of the launching of Telstar 1, the New York Times ran almost 100 articles related to the satellite. Joe Meek’s Telstar composition stormed the pop charts later in the year, and that 1963 New Yorker profile of Pierce ran for 29 pages. Telstar 1 did not outlast some of this acclaim, as it ceased transmission in early 1963, but it had blazed a path. Today, anyone using satellite TV or radio is honouring that decades-old triumph of engineering.

Update: Bill Ray has more at The Register:

Arthur C Clarke is often credited with inventing the idea of satellite communications, though in fact his contribution was to point out that three birds in geostationary orbit could provide global coverage. Geostationary orbit is more than 35,000km up, beyond the reach of radios in 1962, so Telstar’s orbit peaked at less than 6,000km up and dipped down to less than 1,000km during its two-and-a-half-hour circumnavigation.

That dip is also what caused Telstar’s downfall. Its repeated drops into the Van Allen radiation belt did allow the satellite to gather information about the belt (which was part of the plan) but the information it gathered was largely the havoc such radiation plays with electronic circuits. If Wikipedia is to be believed then US nuclear tests at the time had left the Van Allen particularly charged, but either way the satellite failed intermittently for a few months and finally stopped relaying signals entirely in February 1963. However, it remains in orbit to this day, faithfully tracked by the US government as required by international treaties.

Telstar was solar powered, with 3,600 solar cells feeding 19 nickel-cadmium batteries which received a 6GHz signal and retransmitted it with 2.25w of power at 4GHz. The electrics necessary were all suspended by shock-absorbent nylon cords in the middle of the spherical body, which had to spin at 180 rpm for stabilisation (gyroscopes perform the same function on modern satellites, but weren’t reliable enough back then).

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