The European Space Agency (ESA) is Europe’s gateway to space. Its mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world.
Find out more about space activities in our 23 Member States, and understand how ESA works together with their national agencies, institutions and organisations.
Exploring our Solar System and unlocking the secrets of the Universe
Go to topicProtecting life and infrastructure on Earth and in orbit
Go to topicUsing space to benefit citizens and meet future challenges on Earth
Go to topicMaking space accessible and developing the technologies for the future
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The two gold cubes, enclosed in vacuum containers (shown here without the launch lock mechanism), are key to the LISA Pathfinder mission. Each of these electrode containers houses a gold-platinum test mass. LISA Pathfinder will monitor the two cubes as they enter free-fall motion using a high-precision laser interferometer.
The optical bench interferometer is shown between the two masses. This instrument is made from a 20 cm by 20 cm block of Zerodur ceramic glass, and has a set of 22 mirrors and beam-splitters bonded to its surface that direct laser beams. These beams will allow scientists to precisely measure the cubes' motion, position, and orientation without touching them. In this way, LISA Pathfinder will perform the first high-precision laser interferometric tracking of orbiting bodies in space.