Context. The interplanetary dust complex is currently understood to be largely the result of dust production from Jupiter-family comets, with contributions also from longer-period comets (Halley- and Oort-type) and collisionally produced asteroidal dust. Aims. Here we develop a dynamical model of the interplanetary dust cloud from these source populations in order to develop a risk and hazard assessment tool for interplanetary meteoroids in the inner solar system. Methods. The long-duration (1 Myr) integrations of dust grains from Jupiter-family and Halley-type comets and main belt asteroids were used to generate simulated distributions that were compared to COBE infrared data, meteor data, and the diameter distribution of lunar microcraters. This allowed the constraint of various model parameters. Results. We present here the first attempt at generating a model that can simultaneously describe these sets of observations. Extended collisional lifetimes are found to be necessary for larger (radius ≥ 150 μm) particles. The observations are best fit with a differential size distribution that is steep (slope = 5) for radii ≥ 150 μm, and shallower (slope = 2) for smaller particles. At the Earth the model results in ~ 90–98% Jupiter-family comet meteoroids, and small contributions from asteroidal and Halley-type comet particles. In COBE data we find an approximately 80% contribution from Jupiter-family comet meteoroids and 20% from asteroidal particles. The resulting flux at the Earth is mostly within a factor of about two to three of published measurements.

The ATHENA (Advanced Telescope for High ENergy Astrophysics) mission studies and techno log y p reparat io n are c ontinuing to progress. The optics for this future space observatory is based on the Silicon Pore Op t ics (SPO), an d is being evolved in a joint effort by industry, research institutions and ESA.The SPO technology uses the superb properties of monocrystalline Silicon, and spins in technologie s developed fo r t h e s emiconductor industry, benefiting from excellent materials, processes and equipment. In a holistic approach the t echnical and programmatic challenges of the ATHENA optics are being addressed simultaneously. A co mp rehensiv e Technology Development Plan (TDP) was defined and is being implemented to develop this novel X-ray optics t echnology.The performance, environmental compatibility and serial automated production and testing are being addressed in parallel, aiming at the demonstration of the required technology readiness for the Athena M issio n A d opt ion Rev iew ( MAR) expected in 2022.

The next generation X-ray observatory ATHENA (Advanced Telescope for High ENergy Astrophysics) requires an optics with unprecedented performance. It is the combination of low mass, large effective area and good angular resolution that is the challenge of the X-ray optics of such a mission. ATHENA is the second Large Class mission in the Science Programme of ESA, and is currently in a reformulation process, following a design-to-cost approach to meet the cost limit of an ESA L-class mission.The Silicon Pore Optics (SPO) is the mission enabler being specifically developed for ATHENA, in a joint effort by industry, research institutions and ESA. All aspects of the optics are being addressed, from the mirror plates and their coatings, over the mirror modules and their assembly into the ATHENA telescope, to the facilities required to build and test the flight optics, demonstrating performance, robustness, and programmatic compliance.The SPO technology is currently being matured to the level required for the adoption of the ATHENA mission, i.e., the start of the mission implementation phase. The monocrystalline Silicon material and pore structure of the SPO provide this optics with excellent thermal and mechanical properties. Benefiting from technology spin-in from the semiconductor industry, the equipment, processes, and materials used to produce the SPO are highly sophisticated and optimised.

The ATHENA mission, under study and preparation by ESA as its second Large-class science mis sio n, req u ires t h e largest X-ray optics ever flown, building on a novel optics technology based on mono crystalline silicon. Referred t o as Silicon Pore Optics technology (SPO), the optics is highly modular and benefits from technology s pin-in from the semiconductor industry. The telescope aperture of about 2.5 meters is populated by 600 mirror modules, accurat ely coaligned to produce a common focus.

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