Aussat 1,2,B1,B2,B3
Optus B1,B2,B3

Used by the Mobilesat communications service to cover main land Australia. Based on the Hughes HS-601 satellite, the company's first 3-axis design, accommodating three bands simultaneously for high power services such as land mobile, large area DBS (Direct Broadcast Service) and HDTV (High Definition Television).

Spacecraft
Solar arrays provide 601 W BOL/489 W after 3 yr., two 19 Ahr nickel cadmium batteries. Attitude control <1 arcmin, determination <0.3arcmin; 3 axis control by 4 reaction wheels, ensuring Sun incidenceangle on panels <30 deg. Bubble memory 134 Mb recorder downlinked onX-band at 264 kbit/sec. The tubular telescoping optical truss is constructed of carbon fiber which is folded for launch, extending by a sliding mechanism in orbit.

Payload
Four x-ray telescopes, consisting of four sets of coaxially aligned multilayer thin foil mirrors provided by GSFC. At the focus of two of the telescopes is a Gas Imaging Spectrophotometer (GIS) of two gas imaging scintillation propotional counters covering 0.7-10 keV. The second focal plane instrument is a Solid-state Imaging Spectrometer of two CCDs covering 0.5-8 keV. This is the first satellite to use CCDs for X-ray astronomy.

Country of Origin	Australia
Customer/User	Mobilesat
Manufacturer(s)	Hughes
Size	229x254x254 cm, deployable solar arrays span 18.3-26m
Orbit	156 deg east
Design Life	10-15 years

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
Aussat 1	1985-076B	8/27/85	ESMC	STS 51I	GEO	655
Released by STS 51I 8/27/85; 158 deg W
Aussat 2	1985-109C	11/27/85	ESMC	STS 61B	GEO	1259
Released by STS 61B 11/28/85; 156 deg E
Aussat B1 (Optus B1)	1992-054A	8/13/92	Xichang	CZ-2E	GEO	1600
160 deg E
Aussat B2 (Optus B2)	1992-090A	12/21/92	Xichang	CZ-2E	LEO	1600
Exploded 45 seconds after launch; debris placed into orbit
Aussat B3 (Optus B3)	1994-055A	8/27/94	Xichang	CZ-2E	GEO	3000
Telephone; TV; mobile communications; air traffic control; 156 deg E