Page 29 - EngineerIT October 2021

Sardinia and Corsica, imaged by UoSAT-1 UoSAT-1 report

The result of the test was a change of material for the structure,
and then it was onwards towards flight assembly. Martin called in more
favours and a proper vibration testing campaign was completed at
BAE Stevenage – now an Airbus site - and magnetic calibration was
also done for free at Goddard Space Flight Centre by the scientist Dr
Mario Acuna who designed the magnetometers for Viking & Voyager.

There’s no such thing as a free launch - or is there?
Launch was another example of the power of Martin’s persuasive
abilities – with the help of AMSAT-USA, he copped a free NASA
flight on board a DELTA rocket as a secondary payload underneath a
NASA scientific satellite. UoSAT-1 was placed into a 560 km 3am-3pm
sun-synchronous orbit on 6 October 1981 and in-orbit operations were
conducted from the tracking ground station at the University of Surrey.
Initially UoSAT-1 was commanded in orbit by hand-generated codes Magnetic calibration testing at the Goddard Space Flight Centre
uploaded using a bank of eight 0-1-0-1 manual switches but within a
year the team rigged up early (8080) home computers and an array Regular reports on the status of the satellite were compiled into
of TV monitors saved from a skip to improve telemetry displays and a weekly ‘news sheet’ and broadcast by UoSAT-1 – an example of
speed up the functions of the satellite. world-wide communications long before the internet.

Satellite operations and a first image End game
Neville Bean, SSTL’s longest serving member of staff after Martin After eight years of operations, UoSAT-1 re-entered the Earth’s
himself, carried out many of the satellite’s operations, often late atmosphere on 13 October 1989 and burned up over the Indian Ocean.
at night. The first image from UoSAT-1 was “interesting”, possibly It was still transmitting and telemetry was received on 145.825 MHz by
capturing the rim of the Earth but the second image downloaded was radio amateurs as it re-entered.
clearly of Sardinia and Corsica - success! SSTL’s philosophy of pioneering ingenuity, coupled with a healthy
UoSAT-1 was out of operation for three months following an dose of pragmatism, was born from those UoSAT-1 years, and is now
operator error – where both transmit channels were inadvertently captured in their vision statement:
switched on simultaneously, causing signal jamming on the on-board “SSTL pioneers audacious new satellite technologies, products and
command receivers. In another bold calling in of a favour, assisted by services and shares its know-how to enable advancement in space.” n
AMSAT US, the signal was unlocked using a powerful signal from the
3MW eirp VHF transmitter at Stanford USA. In 1985 Surrey Satellite Technology Ltd was formed as a spin-
out company to transfer the results of research into a commercial
enterprise. The company grew steadily and has worked with a wide
A worldwide following range of international customers and partners, building and launching
UoSAT-1 was back in the game and transmissions on 145.825 MHz ~70 sateliltes for 22 countries over the following three decades.
VHF were received by thousands of radio amateurs and schools In 2009 Airbus bought the majority shareholding from the
worldwide using AFSK ASCII, RTTY and the ‘digitalker’ using very University of Surrey, allowing SSTL to fulfil its growth potential.
simple equipment. SSTL is a wholly owned subsidiary of Airbus. n

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