GFZ Section 1.2, together with Section 1.3, has preformed between 2021 and 2023 a study within ESA´s Third Party Mission Program to

1. Investigate options to continue a two-satellite GRACE-FO mission after failure of the redundant Instrument Processing Unit (IPU) on GRACE-FO-2 (substituting the failed primary IPU since already October 2018) and consequent non-availability of microwave tracking data (GPS, K-band ranging (KBR)) based on Laser Ranging Interferometer (LRI) and Satellite Laser Ranging Data.
2. Characterize the LRI data to maximize the scientific return for MAGIC (Mass change And Geosciences International Constellation). The main goal is to investigate and assess GRACE-FO LRI data quantitatively and qualitatively for global gravity field recovery and evaluate its potential benefits against the nominal KBR measurements. Since the LRI is currently successfully operated as a technology demonstrator on GRACE-FO with significantly lower noise compared to KBR, the key Satellite-to-Satellite Tracking (SST) instrument of the MAGIC constellation will be based on LRI technology. During this study, valuable insights and lessons learnt from LRI real data assessment should serve as input for MAGIC’s mission system design in order to contribute to an improved LRI data product serving as the main observable of the MAGIC mission.
3. Perform full-scale end-to-end simulations of selected scenarios for in-line pairs of two satellites and four satellites in a Bender-type double-pair constellation, as well as 3-pair satellite formation consisting of an in-line pair and a third satellite in pendulum configuration (i.e. Advanced Pendulum). The main goal is to identify optimized Advanced Pendulum and MAGIC constellations regarding space-time sampling and maximizing sensitivity to temporal Earth´s gravity changes that are caused mainly by mass transport processes in continental hydrology hydrosphere, oceans, atmosphere, cryosphere, and solid Earth.
4. Demonstrate the value of GRACE/GRACE-FO Level-3 products for applications in Climate Sciences and Hydrometeorology.

Project Partners:

• Max Planck Institute for Gravitational Physics (Albert-Einstein-Institute)
• HafenCity University Hamburg

Project Duration:

• 05/2021-10/2023

Funding:

• ESA