In August 1999, Hughes Space and Communications International, now Boeing Satellite
Systems, was awarded two satellite contracts from Société Européenne des Satellites
(SES) of Luxembourg. The company ordered its tenth Boeing satellite, ASTRA 3A, in August
2000. The spacecraft is stationed at the orbital position of 23.5 degrees East longitude.
ASTRA 3A is a Boeing BSS-376HP model.
Astra 2D, the first spin-stabilized satellite in the SES fleet, is a Boeing 376HP, for
high-power, satellite. It was successfully launched on an Ariane 5 on Dec. 19, 2000. The
Boeing 376 is one of the most popular spacecraft models. The delivery-in-orbit contract
includes the satellite, launch services, and ground station control software for use at
the control center, plus training for new satellite controllers. The Astra satellites are
controlled from the SES ground station at Betzdorf in Luxembourg.
Astra 2D is the 55th 376 to be ordered from Hughes and Boeing. It will carry 18
traveling-wave tube amplifiers, 16 of which will be active. The signals will be
transmitted via 39 watt traveling-wave tube amplifiers. Astra 2D will deliver digital
direct-to-home television to Great Britain and Ireland. Two of the satellite's four
on-board receivers will be used at any given time.
ASTRA 3A will help SES ASTRA meet growing demand for digital satellite services and
will provide follow-on capacity for Deutsche Telekom's Kopernikus
satellite at 23.5 degrees East. ASTRA 3A has a contracted service life of at least 10
years. The satellite provides high-power cable and direct-to-home broadband services to
Germany, Austria and Switzerland. ASTRA 3A, a spin-stabilized spacecraft, operates with 20
active Ku-band transponders. The satellite was launched on 28 March 2002, aboard an Ariane-44L H10-3 rocket.
The BSS-376HP spin-stabilized spacecraft consists
of two main sections. One is the spinning section, which contains the apogee kick motor,
power system, primary propulsion, and most of the attitude control and command and
telemetry subsystem elements. The fully redundant subsystem controls and monitors the
spacecraft through all mission phases. The primary propulsion subsystem controls
spacecraft orbital velocity, inclination, attitude, and spin speed. The other main section
of the spacecraft is the despun portion, which houses the customized communications
payload, including the transmitters, receivers, and antennas.
All BSS-376 models have two telescoping cylindrical
solar panels. These panels and the deployable antennas are stowed for compactness during
launch. The highly reliable design makes full use of a nickel-hydrogen battery to maintain
uninterrupted broadcasting during eclipses. The Astra 2D and 3A solar panels use gallium
arsenide solar cells similar to those proven on previous Hughes spacecraft. The 376 design
minimizes the number of required mechanisms and has never had a deployment failure.
In early January 2023, Astra 2D was put into a graveyard orbit.
