Official name OSCAR 18 (WEBERSAT)
Alternative name Webersat
Cospar ID 1990-005F
Norad ID 20441
Launch date 1990-01-22
Launch site FRGUI
Launch vehicle Ariane-40 H10
Country/Organization USA
Type application Amateur communication, imaging
Operator Weber State University Center for Aerospace Technology (CAST)
RCS size MEDIUM
Decay date ON ORBIT
Period (min) 100.46
Inclination (deg) 98.89
Perigee (km) 773
Apogee (km) 788
Eccentricity 0.00960922485586163
Mean motion (revs. per day) 14.3340633087796
Semi-Major axis (km) 7158.635
Raan (deg) 125.5825
Arg of perigee (deg) 321.4856
Shape Hex Poly
Mass (kg) 13.88
Height (m) 0.3
Width (m) 0.23
Depth (m) 0.3
Span (m^2) 0.3
Contractors Weber State University Center for Aerospace Technology (CAST)
Equipment CCD Color Camera, Visual Light Spectrometer
Propulsion None
Configuration AMSAT-NA Microsat
Power Solar cells, batteries

Webersat (WO 18, OSCAR 18) was launched on the first ARIANE ASAP flight V35 with SPOT 2, on the 22. January 1990 (01:35:27 GMT) into an 780 km sun-synchronous, 98 degree inclined orbit, this 16 kg amateur radio micro-satellite was built by Weber State University's Center for Aerospace Technology (CAST). It has a full colour CCD camera, Digital Store and Forward packet communication transponder, spectrometer, and particle impact detector. It is box shaped with dimensions of 317 × 230 × 230 mm, with four solar panels and weighs 16.03 kg. Downlink frequency is 437.104 MHz SSB 1200 Baud PSK AX.25

It also carries a CCD NTSC video recorder, digitised to provide 209 by 274 km coverage snapshots using a mechanical shutter. A piezoelectric Particle impact detector measures the micrometeorite environment. A light spectrometer employing an NEC linear CCD measures the spectrum of sunlight reflected from the atmosphere. An L-band video uplink receiver allows NTSC video uplink to be digitised. The satellite employs a V40 processor running at 9.83 MHz, with 8MBytes of RAM. The ADCS systems comprises a horizon sensor using two photodiodes with 22° field of view, a fluxgate magnetometer, permanent magnets, hysteresis coils, and black/white painted antennas for spin control similar to a "photometer".

The satellite suffered an apparent radiation induced computer failure on the 23. August 1997, which recovered in November 1997. It was officially declared non-operational in 1998 when engineers were unable to resolve a software crash.

Satellite COSPAR Date LS Launch Vehicle Remarks
OSCAR 18 (WEBERSAT) 1990-005F 1990-01-22 FRGUI Ariane-40 H10 with SPOT 2, UoSAT 3, Uosat 4, DOVE, PACSAT, LUSAT