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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 these 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 (Advanced Telescope for High ENergy Astrophysics) mission studies and technology preparation are continuing to progress. The optics for this future space observatory is based on the Silicon Pore Optics (SPO), and 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 technologies developed for the semiconductor industry, benefiting from excellent materials, processes and equipment. In a holistic approach the technical and programmatic challenges of the ATHENA optics are being addressed simultaneously. A comprehensive Technology Development Plan (TDP) was defined and is being implemented to develop this novel X-ray optics technology. 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 Mission Adopt ion Review (MAR) expected in 2022.

The development of the X-ray optics for ATHENA (Advanced Telescope for High ENergy Astrophysics)[1-4], the selected second large class mission in the ESA Science Programme, is progressing further, in parallel with the payload preparation and the system level studies. The optics technology is based on the Silicon Pore Optics (SPO) [5-48], which utilises the excellent material properties of Silicon and benefits from the extensive investments made in the semiconductor industry. With its pore geometry the SPO is intrinsically very robust and permits the use of very thin mirrors while achieving good angular resolution. In consequence, the specific mass of the resultant ATHENA optics is very low compared to other technologies, and suitable to cope with the imposed environmental requirements. Further technology developments preparing the ATHENA optics are ongoing, addressing additive manufacturing of the telescope structure, the integration and alignment of the mirror assembly, numerical simulators, coating optimisations, metrology, test facilities, studies of proton reflections and meteorite impacts, etc. A detailed Technology Development Plan was elaborated and is regularly being updated, reflecting the progress and the mission evolution. The required series production and integration of the many hundred mirror modules constituting the ATHENA telescope optics is an important consideration and a leading element in the technology development. The developments are guided by ESA, implemented in industry and supported by research institutions. The many ongoing SPO technology development activities aim at demonstrating the readiness of the optics technology at the review deciding the adoption of ATHENA onto the ESA Science flight programme, currently expected for 2021. Technology readiness levels of 5/6 have to be demonstrated for all critical elements, but also the compliance to cost and schedule constraints for the mission.

The work on the definition and technological preparation of the ATHENA (Advanced Telescope for High ENergy Astrophysics) mission continues to progress. In parallel to the study of the accommodation of the telescope, many aspects of the X-ray optics are being evolved further. The optics technology chosen for ATHENA is the Silicon Pore Optics (SPO), which hinges on technology spin-in from the semiconductor industry, and uses a modular approach to produce large effective area lightweight telescope optics with a good angular resolution. Both system studies and the technology developments are guided by ESA and implemented in industry, with participation of institutional partners. In this paper an overview of the current status of the telescope optics accommodation and technology development activities is provided.

Within the ATHENA optics technology plan, activities are on-going for demonstrating the feasibility of the mirror module integration. Each mirror module has to be accurately attached to the mirror structure support by means of three isostatic mounts ensuring minimal distortion under environmental loads. This work reports on the status of one of the two parallel activities initiated by ESA to address this demanding task. In this study awarded to the industrial consortium, the integration relies on optical metrology and direct X-ray alignment. For the first or “indirect” method the X-ray alignment results are accurately referenced, by means of a laser tracking system, to optical fiducial targets mounted on the mirror modules and finally linked to the mirror structure coordinate system. With the second or “direct” method the alignment is monitored in the X-ray domain, providing figures of merit directly comparable to the final performance. The paper updates on the laser tracking characterization results of 2 mirror modules, performed at PTB’s X-ray Parallel Beam Facility (XPBF 2.0) at BESSY II. The same 2 mirror modules have then been co-aligned and integrated in a technology demonstrator, with performance verified in full illumination at Panter. The paper provides an overview of the results obtained from the technology development activities.

Within the ATHENA optics technology plan, activities are on-going for demonstrating the feasibility of the mirror module Assembly Integration and Testing (AIT). Each mirror module has to be accurately attached to the mirror structure by means of three isostatic mounts ensuring minimal distortion under environmental loads. This work reports on the status of one of the two parallel activities initiated by ESA to address this demanding task. In this study awarded to the industrial consortium, the integration relies on opto-mechanical metrology and direct X-ray alignment. For the first or “indirect” method the X-ray alignment results are accurately referenced, by means of a laser tracking system, to optical fiducial targets mounted on the mirror modules and finally linked to the mirror structure coordinate system. With the second or “direct” method the alignment is monitored in the X-ray domain, providing figures of merit directly comparable to the final performance. The integration being designed and here presented, foresees combining the indirect method to the X-ray direct method. The characterization of the single mirror modules is planned at PTB’s X-ray Parallel Beam Facility (XPBF 2.0) at BESSY II, and the integration and testing campaign at Panter. It is foreseen to integrate and test a demonstrator with two real mirror modules manufactured by cosine.