The Venus Express spacecraft is roughly a cubic box (dimensions 1.65 m x 1.7 m x 1.4 m high). The overall configuration of the spacecraft is a core structure, surrounded by an outer structure.

Structure of Venus Express spacecraft

The core structure comprises:

• A Launch Vehicle Adapter (LVA) ring, machined from a solid aluminium cylinder approximately 940 millimetres in diameter and 200 millimetres high, which formed the main load transfer path from the spacecraft body to the launch vehicle interface
• Two tank beams supporting the lower bosses of the propellant tanks and embedded in the LVA ring
• Two upper tank floors, supporting the upper bosses of the propellant tanks
• One Lower Floor
• One shearwall in the Y direction, providing stiffness in the X-Z plane
• Two shearwalls in the X direction, each one split in two panels and providing stiffness in the Y-Z plane

The spacecraft is divided into six compartments by the walls of the core structure.

The outer structure comprises:

• The top floor (+Z face)
• The ±Y sidewalls, which were open during spacecraft integration
• The ±X lateral closure panels, which are divided into three sections each to allow separate access into the various compartments of the spacecraft
• Various dedicated equipment support panels and brackets

All these elements are made of aluminium alloy, either from forgings (LVA ring, tank beams and main brackets) or from honeycomb sandwich panels. The panels are made from honeycomb of ten to twenty millimetres thickness, bonded to aluminium face sheets with a thickness varying between 0.2 and 0.3 millimetres, with up to 0.5 millimetres of additional thickness for local reinforcements.

The payload units are accommodated according to their main needs. Payloads needing stringent thermal control and/or pointing performances (PFS, SPICAV and VIRTIS sensors) are gathered in the -X compartment, close to the -X cold face of the spacecraft and to the Attitude and Orbit Control System reference units (the inertial measurement units and the star trackers).

The MAG sensors and deployable boom are accommodated outside the spacecraft, on the top floor. The ASPERA-4 sensors are accommodated on the lower floor and the -Y sidewall.

The propulsion system accommodation is the same as on Mars Express. The two propellant tanks are mounted in the centre part of the core structure and the propulsion units are accommodated on the +X shearwall and on the lower floor. The main engine is located under the lower floor and orientated in the -Z direction, while the eight thrusters are located at the four lower corners of the spacecraft.

The two solar wings are mounted to the ±Y sidewalls and can rotate around the Y axis (same interfaces as Mars Express).

There are two fixed high gain antennas. The HGA1 antenna is accommodated on the +X closure panel, as is the case on Mars Express. The HGA2 antenna is accommodated on the top floor, pointing in the -X direction.

The majority of the electronics units are accommodated on the inner side of the ±Y sidewalls.

	Introduction
	Thermal Control