The authentication of GNSS signals poses a challenging problem. Before exploiting a signal (e.g. its pseudo-noise sequence) it would be desirable for the receiver to have assurance quickly (ideally in less than 10-s) and reliably that the signal is actually coming from a navigation satellite and not from a spoofer (e.g. unknown pseudolite, delayed version of the same signal). Classical data-level authentication solutions work after signal demodulation (PN sequence de-spreading), require data-level cryptography (shared secrets) and key management.

Achievements:

• Successful plasma ignition was demonstrated with SSI-developed subsystems and the IRS IPT lab model. The ignition test campaign was conducted from 11th -14th April 2023 at IRS, Stuttgart.

• Two PPU amplifiers were designed, simulated, built, and tested; the Class E amplifier successfully ignited the thruster.

High-sensitivity GNSS receivers architectures are of interest in harsh propagation conditions in order to be able to keep tracking GNSS signals even at very low C/No conditions (typically down to around 10-20 dBHz, depending on the signal being tracked). For this purpose, open-loop techniques can be used in the estimation of the code delay and the carrier phase and/or frequency, targeting a more robust estimation of those observables. In this process, advanced signal estimation techniques can be applied for the optimum exploitation of e.g. multi-correlation samples.

The architecture of an SPS system requires that the SPS maintain constant visibility to both the Sun and the ground station. This immediately implies a so-called Geosynchronous Equatorial Orbit (GEO), which is also called a Geostationary Orbit; or a near-GEO Geosynchronous Orbit (GSO). These are substantially the same orbits that are used for existing communications satellites.

The European Charging Station for the Moon (ECSM) is to be integrated within the EL3 Architecture, which provides the function of transportation of ECSM to the lunar surface. The Power Station mission is envisaged as possible EL3 payload and it aims at providing power, at a strategic location on the lunar surface, during lunar day and night to ESA and International partner assets. It is in line with the envisioned international lunar exploration architecture.

Uncertainties on atmospheric densities and temperatures are major risk drivers for atmospheric entry and orbital maneuvers such as aerobraking or aerocapture. The EnVision mission scenario foresees orbit perigee lowering down to about 140km using aerobraking. Europe has gained a good expertise during the Venus Express mission, however there is no easily accessible model not to say engineering model to rely on for mission design at Venus.