Internal Research Fellow; PostDoc in NGGM Project GNC and Simulation

Internal Research Fellow (Post Doc) in NGGM Project GNC Performance and Simulation

Job Requisition

Date Posted: 2 February 2026

Closing Date: 23 February 2026 23:59 CET/CEST

Directorate:
Earth Observation Programmes

Gravity is a well-established observable, and has been integral to Earth observation from space since the beginning, as shown, for example, by the measurement of Earth’s oblateness in 1958. Measuring the gravity field reveals Earth’s state of mass distribution and its dynamics. It also provides the geoid as a reference for sea level, global ocean circulation and height systems. In addition, the temporal variations of gravity and the geoid help to measure mass exchange processes in the Earth system.

Knowledge about the time-varying gravity field contributes to all Earth observation science applications, including hydrology, cryosphere, solid Earth, oceanography, atmosphere, geodesy and climate research.

The measurement principle of the Next Generation Gravity Mission (NGGM) will rely on the high-accuracy measurement of the variation in inter-satellite distance due to the time-varying gravity field via a laser tracking instrument and accelerometers to measure the non-gravitational accelerations acting on each satellite, which, in the data processing, will be separated from those caused by the gravity signal. NGGM will make it possible to measure and monitor Earth’s time-varying gravity field and its trends at sub-weekly, monthly to seasonal, and long-term timescales in regions up to 70 North/South at a high resolution in time (down to 5 days) and space (down to 100 km).

NGGM is set to launch in 2032.

You will become an integral part of the NGGM Project System Section within the broader ESA NGGM Project Team, which consists of highly specialised engineers from various engineering disciplines.
The Section currently has nine members who work together closely and take pride in being part of an ambitious and motivated team. You will have the opportunity to contribute to a real project implementation, and your work will provide essential inputs for one of the most challenging and complex ESA Earth observation missions in the near future.

Specifically, your research will provide critical insight for NGGM performance assessment and predictions.

The Next Generation Gravity Mission consists of a pair of satellites providing two types of measurement to map Earth’s gravity field. The first measurement is the variation of inter-satellite distance, measured by a laser interferometer. The second is the non-gravitational acceleration at the centre of mass of each satellite, obtained from ultra-sensitive accelerometers on board each platform. This translates into tight control requirements of the fine relative pointing accuracy between the two satellites and the linear and angular accelerations sensed by the accelerometers.

These objectives are achieved via a Drag-Free Attitude and Orbit Control System (DFAOCS) to provide each spacecraft with a drag-free environment and fine pointing capabilities. The control performance of the DFAOCS must then be assessed by means of a high-fidelity end-to-end simulator. The current design of the NGGM DFAOCS could benefit from the latest advances in control theory and the use of a robust control framework in which system design, parametric sensitivity and worst-case analysis can be rigorously performed using state of-the-art tools.

The goal of the proposed research is to explore the use of advanced control design and verification techniques for the design of the Drag-Free Attitude and Orbit Control System of the Next Generation Gravity Mission. To achieve this goal, four different objectives must be fulfilled:

• Set up a high-fidelity end-to-end simulator for the Drag-Free Attitude and Orbit Control System.
• Set up a linear modelling framework for frequency domain design and verification using linear fractional representations.
• Prototype and implement advanced control methodologies to meet the DFAOCS performance and stability objectives.
• Demonstrate the end-to-end stability and performance capabilities of the DFAOCS with…