Observation of gravitational waves (g.w.) in the mHz region is extremely promising for the wealth of sources and processes that can be studied. That frequency region is only accessible from space, and that is the motivation of the ESA mission eLISA, scheduled for the mid 2030’s.
We will report, fresh after disclosure, on the first results of the space experiment LISA Pathfinder, a feasibility demonstrator, flying now and performing tests of free fall and related technologies.