LISA Pathfinder

Vega placed LISA Pathfinder in a low orbit, and the spacecraft then raised itself toward the Sun-Earth L1 point, about 1.5 million km from Earth. It was built to hold two test masses in near-perfect free fall, a test of the technology for LISA, a planned space-based gravitational-wave observatory. In April 2016 ESA announced that the mission had shown LISA to be feasible.

ESA declared Vega operational after this flight.