The In Orbit Validation (IOV) phase is designed to test the new European satellite navigation system under real mission conditions. During this phase, EADS Astrium in Ottobrunn, Germany, will assume system leadership for the space segment and initially take overall responsibility for the construction of the first four of 30 satellites. In Ottobrunn, important components such as the attitude control system will be designed and manufactured. In conjunction with Dutch Space, the company will also provide the solar arrays for the four satellites, while the propulsion units will come from EADS SPACE Transportation in Lampoldshausen, Germany.

Responsibility for the payload on board the four satellites and also the ground control segment, which provides satellite control, lies with EADS Astrium in the United Kingdom. EADS Astrium in Portsmouth, UK, will assume system responsibility for the globally deployed ground control segment covering the 30 satellite constellations in orbit. In addition, Portsmouth will design and manufacture the onboard navigation payload, which generates and transmits the navigation signals to users, and also important equipment such as the solid-state power amplifiers.

EADS SPACE in France and Spain will also contribute to the IOV phase. The French facility is involved in the ground mission segment, while the Spanish companies will contribute the navigation antennas as well as have involvement in the space segment system engineering.