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Galileo

Jump to: Mission Objectives, Mission Instrumentation, Mission Parameters, Additional Information

Mission Photos:

Galileo Satellite
Courtesy of ESA

Mission Objectives:

Galileo is a satellite radio navigation system initiative launched by the European Union and the European Space Agency. Galileo consists of a constellation of 30 satellites (27 operational satellites plus 3 satellites in reserve) and ground stations providing position information to users in many sectors (transportation, social services, justice system, custom services, public works, search and rescue, etc.). Two experimental spacecraft were launched in 2005 and 2008 as part of the Galileo System Test Bed V2: GIOVE-A (Galileo In-Orbit Validation Element, formerly GSTB-V2/A) and GIOVE-B (formerly GSTB-V2/B).

The main objectives of the Galileo system are:

  • Provide global navigation satellite system specifically for civilian purposes
  • Generate new, large markets and provide the critical advance in technology for Europe and its partners
  • Provide global Search and Rescue (SAR) function

The Galileo system consists of global, regional and local components. The global component consists of the satellites and ground segment. The regional component consist of a number off External Region Integrity Systems (ERIS) implemented to obtain higher integrity services independent of the Galileo system. Local components may be deployed for enhancing the performance of Galileo locally. These will enable higher performance such as the delivery of navigation signal in areas where the satellite signals cannot be received.

All Galileo satellites will be equipped with LLR arrays to provide precise orbit determination. Both routine SLR tracking and occasional campaigns with more intense tracking will be required. Laser tracking of Galileo will be comparable to GLONASS and GPS tracking (perhaps up to 40 percent more return energy than GPS).

Due to a launch anomaly, the first two Fully Operational Capability (FOC) Galileo satellites (-201 and -202), launched August 22, did not reach their expected orbit. A series of maneuvers were used to push the satellites to useable orbits.

Mission Instrumentation:

Galileo will have the following components:

  • Satellite components:
    • L-band antenna for transmitting navigation signals
    • Search and rescue (S&R) antenna to pick up distress signals
    • C-band antenna to receive signals from up-link stations
    • Two S-band antennas for transmiting housekeeping data and receiving control commands
    • IR Earth sensors for spacecraft pointing
    • FSS sun sensors for spacecraft pointing
    • Laser retro-reflector array for orbit determination
    • Space radiators for heat exchange
  • Interior payload:
    • Passive maser clock
    • Rubidium clock
    • Clock monitoring and control unit
    • Navigation signal generator
    • Remote terminal unit
  • Interior service module:
    • Solar array drive mechanism (SADM)
    • Gyroscopes
    • Reaction wheels
    • Magneto bar
    • Power conditioning and distribution unit
    • On-board computer
Mission Parameters:
Galileo-101 Galileo-102 Galileo-103 Galileo-104
Sponsor: ESA ESA ESA ESA
Expected Life: 12 years 12 years 12 years 12 years
Primary Applications: Positioning Positioning Positioning Positioning
COSPAR ID: 1106001 1106002 1205501 1205502
SIC Code: 7101 7102 7103 7104
NORAD SSC Code: 37846 37847 38857 38858
Launch Date: 21-Oct-2011 21-Oct-2011 12-Oct-2012 12-Oct-2012
RRA Size:        
RRA Shape: planar planar planar planar
Reflectors: 84 corner cubes 84 corner cubes 84 corner cubes 84 corner cubes
Size of Reflector: 33 mm diameter, 23.3 mm height 33 mm diameter, 23.3 mm height 33 mm diameter, 23.3 mm height 33 mm diameter, 23.3 mm height
Orbit: near-circular near-circular near-circular near-circular
Orbital period: 14.08 hrs 14.08 hrs 14.08 hrs 14.08 hrs
Inclination: 56 degrees 56 degrees 56 degrees 56 degrees
Altitude: 23,220 km 23,220 km 23,220 km 23,220 km
Eccentricity: < 0.001 < 0.001 < 0.001 < 0.001

 

Galileo-201 Galileo-202 Galileo-203 Galileo-204
Sponsor: ESA ESA ESA ESA
Expected Life: 12 years 12 years 12 years 12 years
Primary Applications: Positioning Positioning Positioning Positioning
COSPAR ID: 1405001 1405002 1501701 1501702
SIC Code: 7201 7202 7203 7204
NORAD SSC Code: 40128 40129 40544 40545
Launch Date: 22-Aug-2014 22-Aug-2014 27-Mar-2015 27-Mar-2015
RRA Size:        
RRA Shape: planar planar planar planar
Reflectors: 60 corner cubes 60 corner cubes 60 corner cubes 60 corner cubes
Size of Reflector: 28.2 mm diameter, 19.1 mm height 28.2 mm diameter, 19.1 mm height 28.2 mm diameter, 19.1 mm height 28.2 mm diameter, 19.1 mm height
Orbit: eccentric eccentric near-circular near-circular
Orbital period:     14.08 hrs 14.08 hrs
Inclination: 50 degrees 50 degrees 56 degrees 56 degrees
Altitude: 17,000 - 26,210 km 17,000 - 26,210 km 23,220 km 23,220 km
Eccentricity: ~ 0.158 ~ 0.158 < 0.001 < 0.001

 

Galileo-205 Galileo-206 Galileo-208 Galileo-209
Sponsor: ESA ESA ESA ESA
Expected Life: 12 years 12 years 12 years 12 years
Primary Applications: Positioning Positioning Positioning Positioning
COSPAR ID: 1504501 1504502 1507902 1507901
SIC Code: 7205 7206 7208 7209
NORAD SSC Code: 40889 40890 41175 41174
Launch Date: 11-Sep-2015 11-Sep-2015 17-Dec-2015 17-Dec-2015
RRA Size:        
RRA Shape: planar planar planar planar
Reflectors: 60 corner cubes 60 corner cubes 60 corner cubes 60 corner cubes
Size of Reflector: 28.2 mm diameter, 19.1 mm height 28.2 mm diameter, 19.1 mm height 28.2 mm diameter, 19.1 mm height 28.2 mm diameter, 19.1 mm height
Orbit: near-circular near-circular near-circular near-circular
Orbital period:        
Inclination: 56 degrees 56 degrees 56 degrees 56 degrees
Altitude: 23,220 km 23,220 km 23,220 km 23,220 km
Eccentricity: < 0.001 < 0.001 < 0.001 < 0.001
Additional Information: