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 UoSAT-3
(OSCAR-14, VITASAT, HealthSat-1).  - The first of the University of Surrey based Surrey Satellite Technology Ltd. (SSTL) in
the UK, modular microsatellites, launched on the first ARIANE (40) ASAP flight V35 with SPOT-2 (picture1,
picture2), on the 22nd January 1990 (01:35:27 GMT) into an
780km sun-synchronous, 98 degree inclined orbit. It carries a commercial Store and Forward
communications payload with 13MByte of solid state storage and VHF and UHF 9600 bps CPFSK
links. For the first 18 months it supported amateur service, but when this was taken over
by UoSAT-5, it supported VITA, and later SatelLife as HealthSat-1, and Data Trax Inc. (USA).
UoSAT-3 is operated from the SSTL, Guildford, in the U.K. The 45.5kg microsatellite is box
shaped with dimensions 350x350x650mm, with four solar panels on the larger facets, and a
6m gravity gradient boom. The picture right also shows the magnetometer boom. The UoSAT-3
bus was built between June 1988 and January 1990 for a budget of UKP447k [1]. The primary
80C186 on-board computer failed in May 97, and it was decided that the Store and Forward
transponder operations for VITA would be taken over by the more capable PoSAT-1, rather
than develop operational software for UoSAT-3's secondary processor (based on the Zilog
Z80). In 1999 the satellite was configured as an FM voice repeater (VHF to UHF) within the
amateur service.
More detail: [SSTL] [AMSAT]
[1] Evans(Ed), Satellite Communication Systems 2nd Ed., IEE,
1991
Picture (right) courtesy of SSTL.
- UoSAT-4 (UO-15).
- Contained the scientific payloads complement to UoSAT-3, but failed due to an electrical
fault after two days in orbit. The 47.5kg microsatellite was identical in shape to
UoSAT-3. The picture right shows UoSAT-4 in the foreground without its solar panels,
showing its wiring harness and sun-sensors on the top corner. Most of the experiments were
re-flown in 1991 on UoSAT-5.
More detail: [SSTL]
Picture (right) courtesy of SSTL.
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- OSCAR-16 (AO-16,
PacSAT)
- An AMSAT microsatellite launched on the first ARIANE ASAP
flight V35 with SPOT-2, on the 22nd January 1990 (01:35:27 GMT) into an 780km
sun-synchronous, 98 degree inclined orbit. It is dedicated to amateur digital Store and
Forward packet data communications at 1200bps. It is box shaped with dimensions of
150x150x150mm, with four solar panels and weighs 13.34kg. Uplink frequencies are 145.90,
145.92, 145.94, and 145.86 MHz FM 1200 bps Manchester FSK, and downlink frequencies are
437.0513 MHz SSB, 1200 bps RC-BPSK 1200 Baud PSK. A beacon is also carried at 2401.1428
MHz. It was reported to be operational in March 1999.
More detail: [AMSAT] [Whole Orbit Data files]
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- OSCAR-17 (DO-17,
Dove)
- An AMSAT-Brazil microsatellite launched on the first ARIANE ASAP
flight V35 with SPOT-2, on the 22nd January 1990 (01:35:27 GMT) into an 780km
sun-synchronous, 98 degree inclined orbit. It has a Digital Orbiting Voice Encoder (DOVE),
designed to provide synthesised voice messages of telemetry for educational institutions.
It is box shaped with dimensions of 150x150x150mm, with four solar panels and weighs
12.92kg.
After a troubled life to commission the satellite, DOVE stopped transmitting in March
1998. The 145.825 MHz and 2401.220 MHz downlinks are off the air and the satellite has not
responded to ground station control.
More detail at: [SSTL] [AMSAT][Dove
(Italian)]
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- OSCAR-18 (WO18,
WeberSat).
- Launched on the first ARIANE ASAP flight V35 with SPOT-2,
on the 22nd January 1990 (01:35:27 GMT) into an 780km sun-synchronous, 98 degree inclined
orbit, this 12.25kg amateur radio micro-satellite was built by Weber State University Ogden, Utah in
the U.S. 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 150x150x150mm, with four solar panels and weighs 16.03kg. Downlink frequency is 437.104
MHz SSB 1200 Baud PSK AX.25
- It also carries a CCD NTSC video recorder, digitised to provide 130 by 170 mile 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
9.83MHz, with 8MBytes of RAM. The ADCS systems comprises a horizon sensor using two
photodiodes with 22deg 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 23rd
August 1997, which recovered in November 1997.
References
[1] "SPIE Vol 1495 Small Satellite Technology and
Applications (1991) WeberSat A low cost imaging system. R.J.Twiggs, K.W.Reister.Webersat
Data analysis and dynamic behaviour, J.L.Smith.
More detail at: [AMSAT]
[CAST at WSU][Summary at CAST WSU]
- OSCAR-19 (LO-19,
LuSAT)
- Co-ordinated by AMSAT Argentina, the LUSAT microsatellite was launched on the first
ARIANE ASAP flight V35 with SPOT-2, on the 22nd January
1990 (01:35:27 GMT) into an 780km sun-synchronous, 98 degree inclined orbit. It carries
Digital Store and Forward packet communications transponder similar to AO-16. Uplink
frequencies are 145.84, 145.86, 145.88, and 145.90MHz FM 1200 bps Manchester FSK. Downlink
frequency and protocol is AX.25 at 437.125 MHz SSB 1200 bps RC-BPSK. It is box shaped with
dimensions of 150x150x150mm, with four solar panels and weighs 13.76kg.
More detail at: [AMSAT] [Telemetry samples]
Picture (right) courtesy of AMSAT.
- Debut (Orizuru).
- Japanese 50kg microsatellite launched on a Japanese H-I rocket into polar LEO on the 7th
February 1990 0133 UTC. It was placed into a 909x1742km orbit inclined at 99 degrees. It
carried a boom/umbrella combination for test.
- Fuji-2 (FO-20,
JAS-1b).
- Japanese radio amateur satellite launched on a Japanese H-I rocket into polar LEO on the
7th February 1990 0133 UTC. It was placed into a 909x1742km orbit inclined at 99 degrees.
It carries analogue communications transponders as its payload. A picture
(80k) shows the microsat is spherically shaped with 20 facets.
More detail at: [AMSAT]
Picture (right) courtesy of JARL.
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- TERCEL/SECS,
(GLOMR-II, USA 55) 1990-28B
- TERCEL/SECS (Special Experimental Communications System) was launched on a Pegasus
launch vehicle on the 5th April 1990, into a 489x668km orbit inclined at 94.1 degrees. The
68kg satellite was based on the GLOMR bus, built by DSI for
the Navy, in order to carry out communication experiments. Compared to GLOMR it offers
greater data storage, more redundancy and more space qualified hardware. It operates with
two different types of modulation, and was capable of reading remote terrestrial sensors..
The satellite is spherical in shape, "Basketball sized", with 54 facets, and
carries a quad turnstile antenna system. The satellite was unstabilised, and operated as a
store and forward data relay for 3.5 years.
Picture (right) courtesy of CTA.
- Kosmos2064-2071
, 1990-029A-H
- A group of 8, 61kg microsatellites forming part of a CIS military communications
constellation. It was launched from a Cosmos launcher from Plesetsk on the 6th April 1990
and the satellites were placed in orbits near 1400km at 74 degrees in order to drift
apart.
- STACKSAT, POGS/SSR (P87-2)
1990-31A
- STACKSAT for the ONR/USAF was launched on an ATLAS-28E/Altair from the Western Test
Range into a 741km 90 degree inclined orbit on the 11th April 1990. Stacksat comprised
three spacecraft, POGS, TEX and SCE stacked one on top of the other. The DSI built
microsatellites weigh between 68 and 72.6kg each, are cylindrical in shape and are gravity
gradient stabilised. The POGS (Polar Orbiting Geomagnetic Survey) mission for the U.S.
Navy carries a magnetometer to map the Earth's magnetic field for the Defence Mapping
Agency, in order to improve Earth based navigation systems. It also employs a Fairchild
Solid State data Recorder (SSR). Six ground stations were established to provide
world-wide operations.
Picture (right) courtesy of CTA.
- STACKSAT, TEX 1990-31B
- TEX is an experimental communications launched as part of Stacksat satellite It is built
by the DSI for the U.S. Air Force. TEX employs a variable power transmitter to study
ionospheric effects on radio signals.
- STACKSAT, SCE 1990-31C
- SCE, Special Communications Experiment, is a DSI built satellite, launched as part of
Stacksat for the U.S. Navy. SCE TEX employs a variable power transmitter to study
ionospheric effects on radio signals.
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- MACSAT-1,
1990-043A
- The two Multiple Access Communications Satellites were launched for DARPA, stacked on a
SCOUT 212C on the 9th May 1990 into a 608x766km orbit inclined at 89.9 degrees. The DSI
built 61kg microsatellites have a 6m gravity gradient boom with 2.3kg tip-mass and rely on
magnetic coils for spin stabilisation. Their mission was as Store and Forward data
communications, and remote control and data collection, with a design life of 2 years. The
dual 10W downlink was digitally tuneable, and a 65W downlink was also included. A dual
redundant UHF receiver was carried, and dual on-board processors with 2.4 to 16MBytes of
data storage. The structure is 16-sided cylindrical, with solar panels providing 10-17W
orbit average power, and a 150WH redundant NiCd battery. The power bus offers ±15V, 5V
and 28V via DC/DC converters. The spacecraft are separated and held by the launcher using
a SCOUT 25E adapter with marman V clampband, with a total capacity of 200kg.
Picture (right) courtesy of CTA.
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- MACSAT-2,
1990-043B
- Similar to and launched with MACSAT-1, MACSAT-2 failed on the 15th September 1993 due to
human error.
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- BADR-1,
1990-59A.
- BADR-A1 (known as BADR-A before launch) was launched on the 16th of July 1990 from a Chinese Long March-2E launcher
alongside AUSSAT-B into a 201x984km orbit inclined at 28.4degrees, and was built by
Suparco in Pakistan. The spacecraft weighed 52kg. It had 26 facets (picture), and was electrically based on UoSAT-2. It carried Store
and Forward transponder in the 144-146MHz and 435-436MHz bands. Contact was lost on the
20th August due to what is believed to be an electrical failure. More...
[BADR-1 at SUPARCO]
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