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 Ofek-4 - Ofek-4 ('Horizon'), a 280kg Israeli photo reconnaissance satellite was launched into a
retrograde orbit on the 22nd January 1998 from the Israel Air Force Base at Palmahim. The
satellite is reported to have suffered an early failure. The satellite was developed and
built by Israel Aircraft Industries (IAI), and the programme cost, including launcher is
believed to have been US$50m (1998). The satellite was to replace Ofek-3,
and it is expected Ofek-5 will be launched within another 2 years.
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- GFO, 1998-007A
(25157)
- The US Navy GeoSAT-Follow-On, is a 369kg minisatellite based on the Techstar platform.
It was launched on the 10th February 1998 on a Taurus from VAFB alongside two ORBCOMM
satellites, into a 789x881km (779x790 km planned) 108 degree inclined orbit. The missions
follows the 1985 Johns Hopkins Applied Physics lab built Geosat mission. It carries a
precise radar altimeter (<5cm) to measure small changes in sea surface heights
associated with ocean circulation. The altimeter was supplied by Raytheon. A microwave
radiometer is also carried supplied by AIL systems Inc. The spacecraft has 96Mbytes of
on-board storage, and will generate up to 126W orbit average power. Ball Aerospace built
the spacecraft, which has a mission design lifetime of 8 years. The spacecraft cost was
US$46m and the contract was awarded in 1992.
- Early on in the mission, momentum wheel directions were found to be reversed, although
that was rectified in software. It is also reported that the GPS receivers (supplied by
AOA and based on JPL designs) have had trouble acquiring a fix, and that the On-Board
computer sometimes resets unexpectedly. Attitude is reported to be within 0.1 degree of
nadir. The telemetry downlink is at 400.033MHz.
- More...
[GFO home page]
- Globalstar U1, U2, L1, L2 (FM1 to 4), 1998-008A-D,
(25162-5)
- The first 4 out of 48+4 Globalstar satellites in the Space Systems Loral 'Big LEO'
global mobile communications network offering global real time voice, data and fax, were
launched on the 14th February 1998 on a DELTA II launcher from Cape Canaveral. They were
placed into a 1245x1258km 52deg orbit, later to be boosted to 1410km height. More...
[SSHP Globalstar constellation data]
Artist impression (right) courtesy of Space Systems Loral
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- SNOE (STEDI-1)
1998-012A (25233)
- SNOE was launched on the 26th February 1998 on a Pegasus-XL launcher from VAFB, together
with BATSAT, into a 535x580km orbit inclined at 97.7 degrees. The 114kg Student Nitric
Oxide Explorer was built at the University of Colorado's Laboratory for Atmospheric
Research and Space Physics, and analyses and measures the contributions of nitric oxide
from the Sun and magnetosphere to the lower atmosphere. It is one of the two NASA selected
STEDI missions together with TERRIERS, and CATSAT as a backup. It carries an auroral
photometer, and the prime On-Board Computer is Intel 80C186 based. The project includes
Ball aerospace and the National Centre for Atmospheric Research (NCAR). More...
[SNOE at University of Colorado]
Pictures:[Spacecraft][Integrated
on launcher][structure drawing][exploded view]
Artist impression (right) courtesy of U.o.Colorado
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- TRACE,
1998-020A, 25280
- TRACE , the NASA Transition Region and Coronal Explorer, is a 212.9kg minisatellite
which was launched on the 2nd April 1998 from VAFB on a Pegasus-XL into a 602x652km orbit
inclined at 97.8 degrees, dawn-dusk sun-synchronous. The third satellite in the SMEX
series spacecraft was designed by, and will be managed by GSFC NASA . The instrument
was
designed by the Lockheed solar physics group. TRACE is to observe the Sun for one year to
study the connection between its magnetic fields and the heating of the sun's corona. It
was completed for a cost of $39.4m, well within its $49m budget. The spacecraft is
hexagonal in shape employing a semi-monocoque thrust tube design. Four GaAs panels are
deployed at 90 degrees with an areas of 2m2 , and delivering up to 222W. The
spacecraft requires 85W and 35 for the payload from a 28V unregulated supply, and is
augmented by a 9Ah NiCd battery. Remaining power is employed in heating. The power system
employs a Direct Energy Transfer system with partial array shunting. Some multi-junction
test solar cells are also carried. TRACE is three-axis stabilised to within 5 arc-seconds,
using four reaction wheels, three toque rods, three two axis gyros, a triaxial
magnetometer, six course sun-sensors, and the instrument telescope as a fine sun-sensor.
The on-board data handling system employs a 32-bit 80386/80387 processor with 300Mbytes of
solid state storage. A MIL-1553 data bus is used to connect sub-systems, and the payload
is interfaced using an RS422 interface at data rates of up to 900kbps. A 5W S-band
downlink is employed with data rates of up to 2.25Mbps. The uplink command rate is 2kbps.
- The telescope like main instrument fits central on the top of the structure. It measures
1600x300mm diam, and employs an 8.66m focal length lens with 1kx1k pixel Lumigen coated
CCD, passively cooled to -65egC. This offers an 8.5arcminute field of view. The detectors
cover wavelengths in the 17-160nm band. A Cassegrain assembly is used with super-polished
mirrors, and active image motion compensation. More...
[TRACE at NASA][TRACE instrument page at Lockheed]
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- Globalstar FM6, 8, 14,15, 1998-023A-D
- The second 4 out of 48+2 Globalstar satellites in the Space Systems Loral 'Big LEO'
global mobile communications network offering global real time voice, data and fax, were
launched on the 24th April 1998. They were boosted to 1410km height at 52 degrees.
More...
[SSHP Globalstar constellation data]
Artist impression (right) courtesy of Space Systems Loral
- Cosmos 2352-57,
1998-036A to -036F
- A multiple launch of a Tsyklon from Plesetsk Cosmodrome on the 15th June 1998 put six
spacecraft into a 1300x1870km orbit (rather than the intended 1409x1409km orbit), inclined
at 82.6 degrees. The spacecraft are based on the military Strela bus, and are part of the
Gonets LEO data communications network. They will monitor
disasters like oil spills and illicit transport of radioactive cargo, and provide prompt
alerts. The spacecraft weigh 225kg each and are designed for a five year lifetime by NPO
Applied Mechanics (NPO Prikladnoi Mekhaniki of Krasnoyarsk, Russia) for SMOLSAT (Russia).
More...
[SSHP constellations][SSHP Gonets]
 Globalstar (12 satellites FM5,7,9,10-13,16-18, 20,21)- With 8 satellites launched earlier [launch #1, #2] in 1998, the next 12 out of a total of 48+4 Globalstar
satellites in the Space Systems Loral 'Big LEO' global mobile communications network
offering global real time voice, data and fax, failed to reach orbit on a Zenit launcher
from Baikonur on the 9th September 1998. The spacecraft were insured for US$190m (1998).
More...
[SSHP Globalstar constellation data]
Picture:[Launch configuration]
Artist impression (right) courtesy of Space Systems Loral
- SCD-2, 1998-060A
- SCD-2 (Satelite de Coleta de Dados -2), INPE's 115kg follow on mission on SCD-1, was
launched on a Pegasus-XL on the 23rd October 1998. It was launched into a 744x768km, 25deg
inclination orbit, 180 degrees along from SCD1. Its sister spacecraft was to be launched
on the first Brazilian VLS but unfortunately failed. The spacecraft is cylindrical in
shape measuring 1.45m high and 1m diameter. It delivers 70W of power. Uplinks are at
401.635MHz and 2033.2MHz, and downlinks are at 2208MHz and 2267.5150MHz. The
spacecraft is spin stabilised and carries a reaction wheel experiment and magnetorquers to
control the spacecraft spin rate. It carries S-band and UHF communications systems. The
spacecraft will be employed to follow on the task of SCD 1 of data collection from small
stations over the Brazilian territory. In particular it will study hydrology of the
Amazon basin, atmospheric chemistry and be employed in oceanography and weather
forecasting. The satellite mission is reported to have cost US$11m and the launch US$26m
(1998). More...
[SCD2 at INPE][Picture]
Picture and logo courtesy of INPE.
- SWAS, 1998-071A
- SWAS, the 288kg NASA
Submillimeter Wave Astronomy Satellite was launched on the 2nd December 1998 on a Pegasus
XL from VAFB into a 638x651km orbit inclined at 69.9 degrees. SWAS forms part of the NASA
Small Explorer (SMEX) Series. Earlier SMEX missions were SAMPEX, FAST, and TRACE. WIRE is
still to be launched. SWAS was integrated (picture)
at Goddard Space Flight Centre. The mission was built under a US$64m contract (199?). SWAS
will investigate the process involved in the creation of stars, as gas clouds
collapse under gravity. For the first time by direct observation, it will measure the amount of
water and molecular oxygen. SWAS will also measure isotopic carbon monoxide and atomic
carbon, which are believed to be major reservoirs of carbon in star forming clouds.
- SWAS is three axis stabilised and is star pointing with zero momentum bias. It employs
three axis magnetorquers, six coarse sun-sensors, a digital sun-sensor, three axis
gyros and four reaction wheels. It carries a star tracker in order to achieve 38
arc second attitude control, and a separate 8085 processor is employed. Four deployed GaAs solar
arrays measuring 3.4 m2 (600W BOL) generate 230W orbit average using a DET
power system and 21Ah "Super" NiCd battery. The platform requires 150W, and the
instrument requires 59W.A 5W S-band transponder downlinks at 1.8Mbps and uplink command is
at 2kbps. The On Board Computer employs an 80386 processor and 80387 co-processor with
88MBytes of solid state memory, and the On-Board Data Handling system employs a
MIL-STD-1553 data bus.
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- Instruments weigh a total of 102kg, and include a 0.6m telescope with dual 490 to 550GHz
cryogenically cooled sub-millimeter heterodyne detectors, and acousto-optical spectrometer.
The spacecraft structure is Aluminium, and the mission is designed for a one year lifetime
with a two year goal. More...
[SWAS at UMass][SMEX homepage][Harvard][Drawing #1][Drawing #2][Mission Patch]
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