Astra 1D

Part of the Astra program

TV distribution services to Western Europe and the Canary Islands under franchise from the Grand Duchy of Luxembourg. Contracted and controlled by the private company formed in 1985 called Société Europíenne des Satellites (SES). This is the last in a series of 4 medium power satellites, and will act primarily as Astra 1B and 1C's backup. It will also carry four 12.5 Ghz BSS transponders that can be combined for HDTV.

Spacecraft
HS-601 platform. 3-axis unified ARC 22 N and one Marquardt 490 N bipropellant thrusters, Sun and Barnes Earth sensors and two 61 Nms 2-axis gimbaled momentum bias wheels. 1658 kg nitrogen tetroxide & MMH in four spheres. Spin-stabilized in transfer orbit. Twin solar wings of three 2.16 x 2.54 m panels carrying large area silicon cells on Kevlar substrate to satisfy 3.3 kW requirement. Eclipse protection provided by Nickel hydrogen batteries.

Payload
18 eclipse protected transponders, plus six spares with 63W TWTA 10.75-10.95 Ghz FSS (&12.5 Ghz BSS) down Ku-band European beams in 250 Mhz band adjacent (below) to Astra 1C, 26 Mhz bandwidth, eirp 50 dBW min, orthogonal polarization, operating in the FSS range

Country of Origin	Luxembourg
Customer/User	SES
Size	229 x 254 x 254 cm body, 18.3 m span across solar arrays, total volume .227 cu. m
Orbit	19.2 deg E geostationary (above Zaire)
Design Life	15 years min.
Related Sites	Astra Program

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
Astra 1D	1994-070A	11/1/94	Kourou	Ariane 42P	GEO	2924
European DBS and radio; 19.2 deg E