content 18-November-2017 18:43:42

Spacecraft

The Gaia spacecraft is comprised of three major functional modules:

  • The Payload Module containing the optical instrument and all electronics required to manage its operation and process its raw data. For this purpose the Payload Module includes the Video Processing Unit, the Clock Distribution Unit (housing the atomic clock references) and the Payload Data Handling Unit in charge of data storage between two downlink sessions
  • The Mechanical Service Module made of all mechanical, structural and thermal elements supporting the instrument and the spacecraft electronics. In addition, the mechanical SVM comprises:
      - Micro-Propulsion system
      - Deployable sunshield
      - Payload thermal tent
      - Solar arrays
      - Harness
  • The Electrical Service Module offers support functions to the Gaia payload and spacecraft for pointing, electrical power control and distribution, central data management and Radio communications with the Earth

The spacecraft's micropropulsion system for the fine attitude control will be proportional cold gas.


Mass Budget
 

Component Estimated Mass
Payload Module 524 kg
Service Module 868 kg
Spacecraft dry mass total 1392 kg
Micro propulsion propellant 59 kg
Propellant 237 kg
Launch mass 1934 kg
Launch Vehicle Adapter 95 kg
Total launch mass 2029 kg


Power and Energy

The 12.8 m² triple-junction solar array provides up to 1910 W under end-of-life worst case conditions.

Component Power
RF Communications 326 W
Data Management and AOCS 103 W
Electrical power & solar array 117 W
Propulsion (biliquid & micropropulsion) 24 W
Thermal control 0 W
SREM 2.6 W
Payload module 627 W
Total required power 1561 W
Solar array capability 1910 W

 


Last Update: 09 September 2016

For further information please contact: SciTech.editorial@esa.int

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