Martin Gehler: LISA: Observing gravitational waves from space

The LISA mission concept has been selected by the European Space Agency (ESA) as its third large-class mission within the Cosmic Vision programme. LISA, which stands for "Laser Interferometer Space Antenna," is a space-based gravitational wave observatory, consisting of three spacecraft in a triangular formation providing access to the milli-Hertz frequency band of the gravitational wave spectrum.

The distance between the freely floating test masses housed within the spacecraft is monitored over arm-lengths of 2.5 million km at the picometer level by laser interferometry. First ideas for such a mission emerged long before the turn of the century and the concept has evolved over several decades culminating in the proposal of LISA in its current form in 2016. LISA is currently developed with contributions from the ESA member states and NASA as an international partner with an envisaged launch date before 2034.

In this plenary talk, Martin Gehler of the ESA presents the mission concept and its current state of development as well as the technological challenges, especially in the optical metrology chain. He also addresses developments on the telescope, on the optical bench, lasers, and on the interferometric measurement.

Martin Gehler is currently the Study Manager of the ESA, responsible for the pre-development phase of the LISA mission within the Agency's Science Programme. Joining the ESA in 2009, he's been the study manager for multiple future science missions related to fundamental physics, as well as the System Engineer for the preparation of JUICE, a mission to the icy moons of Jupiter. He graduated from RWTH Aachen University with a degree on mechanical engineering with a major in aeronautical and astronautical engineering.