The use of optical (laser) feeder-links for next generation telecommunication satellites is receiving strong interest from commercial telecommunication providers because it will soon not be possible to support the projected growth in bandwidth using radio frequency bands (e.g. Ka-band). Moving to higher radio frequencies such as the Q/V or W-bands does not dramatically improve available bandwidth, while it increases atmospheric attenuation to a level comparable with the laser communication bands. Cloud coverage can be mitigated by site diversity, namely by using multiple (e.g.

Radio Frequency Interference (RFI) impact heavily on a wide variety of space applications/services belonging to different areas, such as Telecommunications, Navigation and Earth Observation. Despite the huge number of interfering signal types, a preliminary classification of Interference may be performed according to the nature of interfering sources: - Intentional interferences. The transmitting events are deliberately performed for attacking other systems (e.g., jamming, spoofing, etc.); - Unintentional interferences.

Background and justification:

•The railway simulation testbed is an essential tool / capability needed to support validation of GNSS receiver technologies / techniques / integrity algorithms for safety-related applications in railway

•Testbed complements field testing allowing conditions that are statistically unlikely to be observed in the field to be simulated in a highly controlled and repeatable environment

Achievements and status:

Increased radiation levels, as a result of space weather, has been recognised as an important risk for spacecraft and launcher operations. Recently threshold levels of solar energetic particle (SEP) flux and solar activity have been considered as a baseline criteria for launches. After the launch of Gaia in 2013, the transfer included manoeuvres reliant upon the AOCS star trackers, operating in interplanetary space and whose reliability could be seriously impacted by radiation storms known as Solar Particle Events (SPEs).

The design of a re-entry vehicle and the analysis of its performance are extremely challenging tasks. The difficulties increase when the understanding of its transient behaviour is sought and grow even further if this transient is affected by uncontrolled phenomena such as the shape change caused by the ablation of the thermal protection material used as heat shield.

All telecommunications satellite radiators are typically covered with a low solar absorptance and a high infrared emittance coating. Because of the high emittance value, the satellite requires more power/battery for heating during eclipse. A tuneable infrared emittance coating can decrease it during an eclipse and can contribute indirectly to a reduction of the battery mass. A low absorptance coating minimises the solar heat load on the radiator and consequently its size and mass.

This activity proposes to implement a reference model for computer simulation of storage of H2 which takes into account the role of molecular excited states. Different materials will be studied as possible candidates (intermetallic compounds, hydrides, organic liquids, nanotubes) in accordance with the existing practice in industrial applications or proposing alternative materials.