Thales Alenia Space Secures Key Contract for ESA's LISA Gravitational Wave Mission

Thales Alenia Space has secured a €16.5 million contract with German prime contractor OHB System AG. This agreement is for the provision of the propulsion subsystem for the European Space Agency’s (ESA) Laser Interferometer Space Antenna (LISA) mission.

Under this Phase B2 contract, the work is anticipated to extend into Phases C and D, potentially increasing the total contract value to €89.5 million.

Understanding LISA: A Pioneering Observatory

LISA is a groundbreaking space observatory designed to study gravitational waves—ripples in space-time predicted by Albert Einstein. It will mark the first space-based mission dedicated to observing these phenomena, offering scientists a unique window into parts of the universe inaccessible through ground-based observatories.

Gravitational waves originate from extreme cosmic events such as merging supermassive black holes and interacting compact stars. LISA's sensitivity aims to enable observation of these phenomena across a frequency range inaccessible from Earth, extending our view of the cosmos to its earliest epochs.

The Crucial Role of Thales Alenia Space UK

Thales Alenia Space UK will be responsible for the design, manufacture, assembly, integration, and testing of the propulsion subsystem. Beyond propulsion, Thales Alenia Space will supply OHB with several other mission-critical systems:

• Spacecraft avionics and control software
• Telecommunications
• The Drag-Free and Attitude Control System (DFACS)

The DFACS is central to LISA, managing constellation acquisition, maintaining critical laser links, and compensating for non-gravitational forces like solar radiation pressure. This ensures the onboard test masses follow a purely geodesic path.

Thales Alenia Space is also tasked with maintaining the mission’s electromagnetic, radiation, and self-gravity environments, managing associated performance budgets for payload operation.

"The mission requires the spacecraft to be engineered such that only the curvature of space-time influences the motion of the onboard test masses. These masses must maintain near-perfect free fall along the measurement axes."

LISA's Architecture and Operations

The LISA constellation will consist of three spacecraft flying in a triangular formation, separated by 2.5 million kilometers. They will orbit either trailing or leading Earth around the sun. Each satellite will carry two reference masses, with laser beams exchanged between spacecraft to measure minute distance changes with sub-atomic precision. The constellation is scheduled for a 2035 launch aboard an Ariane 6 rocket.

Collaborative Expertise and Legacy

Richard Thorburn, CEO of Thales Alenia Space UK, expressed the company's commitment to contributing advanced capabilities and propulsion expertise to this scientific endeavor. Leonardo, which holds a 33% stake in Thales Alenia Space, is contributing key technologies, including highly precise micro-propulsion assemblies for spacecraft attitude control.

Multiple Thales Alenia Space sites across Europe will support the LISA program, with teams in Turin, Gorgonzola (Italy), and Switzerland contributing to various systems and components. The mission builds on the success of LISA Pathfinder, which demonstrated the ability to keep test masses in free fall with extraordinary precision. The high-accuracy propulsion system class previously used on ESA’s Gaia and Euclid missions will ensure each LISA spacecraft can maintain laser alignment across the vast distances.