Exoplanets meet Gravity: How LIFE could benefit from LISA and GRACE-FO laser interferometry

Kurzfassung

The LIFE mission will apply formation flying between its five spacecraft, requiring advanced sensing of inter-satellite position and orientation. These technology requirements are not entirely unique to LIFE, but are shared with other missions, in particular in the fields of gravitational wave astronomy and earth gravimetry. The gravitational wave observatory LISA (Laser Interferometer Space Antenna) is an ESA-lead mission that just passed Mission Adoption. It will utilize heterodyne inter-satellite laser interferometry to perform relative displacement measurements, targeting picometer precision over spacecraft separations of 2.5 million km. Simultaneously, DWS (Differential Wavefront Sensing) and PRN (Pseudo-Random Noise) ranging will be applied, with the former providing angular tracking and the latter absolute distance measurements. The mission GRACE-FO has been demonstrating the feasibility of these technologies in orbit since its launch in 2018. Its LRI (Laser Ranging Interferometer) performs relative distance and angle measurements in the nm range and nrad range, respectively. The department Laser Interferometric Sensing of the German Aerospace Centerʼs (DLR) Institute for Satellite Geodesy and Inertial Sensing has its roots deep in these missions and intends to transfer the technology to a broader range of applications. Here we will give a short overview of the aforementioned satellite missions and highlight two of our developments to explore potential synergies with the LIFE mission: A CubeSat-compatible version of the LRI miniaturizing laser interferometric ranging for a broader range of applications and MiniCAS (Miniaturized Constellation Acquisition Sensor), a versatile sensor system that can be used to acquire and track a constellation of spacecraft.