|Operator||University of Surrey|
|Launch mass||54 kilograms (119 lb)|
|Start of mission|
|Launch date||6 October 1981, 11:27UTC|
|Rocket||Delta 2310 D-157|
|Launch site||Vandenberg SLC-2W|
|Perigee altitude||372 kilometres (231 mi)|
|Apogee altitude||374 kilometres (232 mi)|
UoSAT-1, also known as UoSAT-OSCAR 9 (UO-9), was a British amateur radio satellite which orbited Earth. It was built at the University of Surrey and launched into low Earth orbit on 6 October 1981. It exceeded its anticipated two-year orbital lifespan by six years, having received signals on 13 October 1989, before re-entering the atmosphere.
This was the first of several UoSAT satellites; followed by UoSAT-2.
The Astrid package sold by British firm MM Microwave, consisting of a fixed frequency VHF receiver set and software for the BBC Micro, could display the telemetry frames from either UoSAT-1 or UoSAT-2. UoSAT-1's solar arrays were of an experimental design reused for UoSAT-2.