Nebula Public Library

Passive intermodulation is a real threat to all types of payloads. In some cases, it could even lead to total lost of the spaceship. Despite of this, there is very weak understanding of the parameters that generate this unwanted interference as well as their influence in the amplitude of the interfering signal. In addition, there is a total lack of agreed testing techniques, procedures and methodologies as well as justified test margins, as has already been recently stated by the European community (National Delegations, satellite operators and Eurospace).

Classical control design techniques used for flexible spacecraft are based on single axis design approaches to control the rigid-body motion complemented by low-pass and notch filters to suppress the resonant peaks of the low-frequency flexible modes. These techniques are inherently relying on a priori knowledge of the structural flexible modes and introduce significant conservatism in the control and structural design, dictated by the need to separate the controller bandwidth from the flexible modes frequency.

A previous study (TRP Star sensing based safe mode) confirmed the interest of using star tracker as primary sensor in a generic safe mode: versatility, suitability to complex requirements and constraints (e.g.

Following on from the successful Venus Express mission (2006 – 2014), the EnVision mission is a mission to observe the surface of Venus at an unprecedented resolution, investigating signs of active geology and looking for evidence of the past existence of oceans. EnVision is meant to help in the understanding of why this most Earth-like planet has turned out so differently and open a new era in the exploration of our closest neighbour. EnVision is proposed as a joint mission with NASA, with payload elements funded by the ESA Member States.