The Pre-Galileo GIOVE (Galileo In-Orbit Validation Element) Satellites
GIOVE satellites are aimed at testing Galileo positioning system technologies in orbit.
Galileo satellite test beds: GIOVE
In 2004 the Galileo System Test Bed Version 1 project (GSTB-V1) validates the on-ground algorithms for Orbit Determination and Time Synchronisation (OD&TS). This project, led by ESA and European Satellite Navigation Industries, provides industry with fundamental knowledge to develop the mission segment of the Galileo positioning system.
GIOVE-A
GIOVE-A is the first GIOVE (Galileo In-Orbit Validation Element) test satellite. Built by Surrey Satellite Technology Ltd (SSTL), it successfully launches on 28 December 2005 by the European Space Agency and the Galileo Joint. Operation GIOVE-A’s primary goal is to claim frequencies allocated to Galileo by the International Telecommunications Union (ITU), a process required to be complete by June 2006. The satellite also tests the design of two on-board, rubidium atomic clocks.
GIOVE-A is the first European satellite launched into medium Earth orbit (MEO). It carries two environmental monitors operating almost continuously since launch. They gather vital data about the Galileo intermediate circular orbit environment and help design the full constellation.
GIOVE-B
GIOVE-B, built by Astrium and Thales Alenia Space, has a more advanced payload than GIOVE-A. It is the first satellite to transmit Galileo signals and launches on 27 April 2008 aboard a Soyuz-FG/Fregat rocket from Starsem. After launch, early orbit operations and platform commissioning, GIOVE-B’s navigation payload is switched on and signal transmission begins.
Key facilities in the testing of GIOVE-B signals include:
- GIOVE-B Control Centre at Telespazio’s facilities in Fucino, Italy
- Galileo Processing Centre at ESA’s European Space Research and Technology Centre (ESTEC) in the Netherlands
- ESA ground station at Redu, Belgium
- Rutherford Appleton Laboratory (RAL) Chilbolton Observatory in the United Kingdom.
GIOVE-A2
GIOVE-A2 essentially extends the mission of its predecessor, GIOVE-A. It secures the Galileo programme by maintaining the critical ITU frequency and facilitating the ongoing development of ground equipment. GIOVE-A2 is originally planned for construction by SSTL and launch in the second half of 2008. However, the construction is terminated due to the successful launch and in-orbit operation of GIOVE-B.
In-Orbit Validation (IOV) satellites
The test bed satellites are followed by four IOV Galileo satellites much closer to the final Galileo design. The Search & Rescue feature is not yet installed though. The first two satellites are launched on 21 October 2011 from Guiana Space Centre using a Soyuz launcher. The other two launch on 12 October 2012. These 4 IOV Galileo satellites are constructed by Astrium GmbH and Thales Alenia Space. On 12 March 2013, a first fix is performed using the four IOV satellites.