On January 22nd, 2026, Thales Alenia Space signed a EUR 16.5 million Phase B2 contract with OHB System AG to provide the propulsion subsystem for the European Space Agency’s (ESA) Laser Interferometer Space Antenna (LISA) mission. Under this contract, Thales Alenia Space in the UK will oversee the design, manufacturing, system assembly, integration, and testing of the propulsion subsystem. The company has indicated that this initial phase is expected to be followed by Phases C and D, bringing the total propulsion-related contract value to EUR 89.5 million.
Significance of the LISA Mission
The LISA mission is one of Europe’s most ambitious scientific endeavors. ESA describes LISA as the first space-based observatory dedicated to detecting gravitational waves. The mission will utilize a constellation of three spacecraft flying in a triangular formation, separated by 2.5 million kilometers. The launch is planned for 2035, using an Ariane 6 rocket from French Guiana, with the spacecraft entering a heliocentric orbit.
Importance of the Propulsion Subsystem
The propulsion subsystem contract represents a critical component of the mission rather than a standard equipment order. LISA’s spacecraft must maintain an exceptionally stable environment to ensure the onboard test masses remain in near-perfect free fall, enabling precise gravitational-wave measurements. Thales Alenia Space has emphasized that the propulsion system leverages the precision-propulsion expertise developed for ESA’s Gaia and Euclid missions. This underscores the subsystem’s direct impact on mission performance, beyond routine spacecraft operations.
Broader Industrial Context
The propulsion contract aligns with the broader industrial framework supporting the LISA mission. ESA and OHB initiated the industrial development of LISA in June 2025, with OHB leading the construction of the three-spacecraft space segment under an EUR 839 million prime contract. Around the same time, Thales Alenia Space secured a separate EUR 263 million contract with OHB for other mission-critical elements, including avionics, telecommunications, and the drag-free and attitude control system. Together, these contracts reinforce Thales Alenia Space’s role as a key industrial partner in Europe’s flagship gravitational-wave mission.