Göttingen 2025 – scientific programme
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GR: Fachverband Gravitation und Relativitätstheorie
GR 3: Rel. Geodesy
GR 3.4: Talk
Tuesday, April 1, 2025, 15:15–15:35, ZHG007
Laser Interferometry in Space for Gravity Recovery: Current and Future Missions — •Pallavi Bekal1,2, Vitali Müller1,2, Malte Misfeldt1,2, Martin Weberpals1,2, Reshma Krishnan Sudha1,2, Laura Müller1,2, and Gerhard Heinzel1,2 — 1Max Planck Institute for Gravitational Physics (AEI), Hannover, Germany — 2Leibniz University Hannover (LUH), Hannover, Germany
The Gravity Recovery and Climate Experiment (GRACE) mission's success in measuring the Earth's gravity field provided a path for future twin-satellite gravity missions with more accurate instrumentation. Consequently, after 15 years of operation, GRACE was succeeded by GRACE follow-on (-FO) in 2018. GRACE and GRACE-FO use the conventional microwave instrument (MWI) to measure the distance between the two spacecraft. Since the range is sensitive to the temporal and spatial changes in the Earth's gravity, its measurement calculates global monthly maps of Earth's mass distribution. GRACE-FO, additionally, hosts the first-ever space laser interferometer, the laser ranging interferometer (LRI). The LRI is a technology demonstrator that measures the range of three orders of magnitude more accurately than the MWI, i.e., at the sub-nanometer scale over short timescales. Hence, the future gravity missions GRACE-C(ontinuity) and Next Generation Gravity Mission (NGGM) will only host an evolved LRI-like instrument. We will present our research activities in analysing the LRI data to detect and remove short disturbances, as well as the experiments on the scale factor measurement system (SFMS) and steering mirror (FSM) that improve its implementation for future missions.
Keywords: GRACE-FO; Laser Interferomery; gravity recovery; laser ranging