ARLA/CLUSTER: R60SAT - Relembrando as primeiras emissões do satélite Sputnik 1 há 60 anos desde 1 a 8 de Outubro de 2017

[João Costa > CT1FBF]

Remembering Sputnik 60 years on

A replica of Sputnik 1 satellite

The world’s first satellite, *Sputnik 1*, was launched on October 4, 1957,
by the then Soviet Union that heralded it as a national triumph, and
started the space race.

Not only was this an important achievement, but an historical milestone
that opened space exploration.

The Russian language Radio magazine for radio amateurs published articles
on the proposed telemetry system and the intended downlink frequencies. An
English language version later appeared in the QST magazine of the ARRL.

The United States also revealed its intent to launch a satellite during the
International Geophysical Year 1957 – but the USSR was first.

When launched it had four external antennas to transmit on 20.005 and
40.002 MHz at about 1 watt heard throughout the world by radio amateurs
including those in Australia.

Sputnik, a 58 centimetre diameter polished metal sphere, was seen from
Earth as it travelled 29,000 km/h taking 96.2 minutes for each orbit. It
had no stabilisation system.

There were two aluminium casings that bolted together using a seal to
create an air tight housing for two transmitters plus a simple temperature
and pressure sensing system.

Scientists studying it garnered information, like the density of the upper
atmosphere deduced from its drag on the orbit, and the propagation of its
signals that helped better understand the ionosphere.

At a time the WWV time and frequency standard station near Fort Collins,
Colorado USA stopped its night transmission on 20 MHz to avoid interference
with the telemetry.

The signals continued for 21 days until the life of three silver-zinc
batteries, two for the transmitters and the other for ventilation, ended 26
October. Sputnik burnt up and re-entered earth’s atmosphere on 4 January
1958.

To commemorate Sputnik 1, special callsign R60SAT will be on air from
October 1 to 8. For further information including the awards available,
please visit the qrz.com website.

*Jim Linton VK3PC*
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