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Due to the recent progress in satellite control engineering, tandem flight arrangements of mini-satellites are currently in discussion and
under consideration for future space missions. CubeSat technologies offer an interesting possibility for space-born telescope payloads
based on this approach. In such a scenario, two small satellites will fly at a constant distance of a few meters up to 100 meters. Thereby,
the front satellite will carry the telescope optics and the second satellite the detector system. Related formation flight requirements were
addressed in the NetSat-Mission, composed of four 3U-CubeSats, launched 2020. Space technology challenges concern in particular orbit
control by an appropriate propulsion system as well as precision attitude pointing towards the joint target, and could be transferred from the
NetSat-mission to the proposed Tandem Mission. This will allow space-based telescopes with a long focal length even placed on board of
small or miniature CubeSat-type satellites. Cost effective Kirkpatrick-Baez type X-ray telescopes represent an important application here as
they have longer focal lengths compared to previous astronomical observatories using Wolter I type X-ray mirrors.
Starting in 1951, on the 50th anniversary of the award of the first Nobel Prize for physics
to Wilhelm Conrad Röntgen, the Lord Mayor of the German city of Remscheid has annually awarded
Röntgen Medals to scientists who "in the broadest sense have made a special contribution to the
progress and dissemination of X-ray discoveries in the theoretical and applied sciences". The
Röntgen Medal has become highly recognized in the scientific world. To date, more than one
hundred scientists have received this honour. Through their chronology, this contribution presents a
"Who’s Who" of X-ray science and provides selected insights into their scientific work; with special
focus on the fields of X-ray optics and X-ray astronomy.
In 1895, Professor Wilhelm Conrad Röntgen detected a new kind of radiation that was able to penetrate
solid materials, which he called x-rays. In 1901 Röntgen received the first Nobel Prize in physics in honour of this
ground breaking discovery. The Deutsches Röntgen-Museum in Remscheid in Germany is the institution that
uniquely and comprehensively explores and documents the life and work of W. C. Röntgen and the impact of his
discovery. The museum’s location in Remscheid is not coincidental, with Röntgen’s birthplace only a short walk away from
its exhibits. Every visit to the museum amounts to a unique expedition through the worlds of medicine, science, and
technology. The museum’s emphasis on the diversity of Röntgen’s invention by a multilingual, multi-medial approach
enables all visitors to make their own personal discoveries. The Deutsches Röntgen-Museum in Remscheid is a mustsee
for x-ray scientists from anywhere in the world. This contribution provides an insight into the history of x-rays and
offers a guided tour of the Deutsches Röntgen-Museum and its exhibits.
We address the problem of estimation the sensitivity of astronomical X-ray telescopes of Lobster Eye type , with emphasis on calculation of effective areas for telescopes designed for rocket and CubeSat flights. This parameter is one of the principal parameters when justifying the real space application. Indeed, the larger the effective area is, the more efficient the optical system is, able to provide images of fainter and more distant celestial targets. We discuss the estimation of the effective collecting area of a X-ray telescope by two different methods and then compare the results: the analytical method and then the simulation algorithm.
The goal of this project is to develop satellite components for space-based astronomical satellite payloads. Thereby advanced materials like iridium and innovative manufacturing technologies will be applied. After environmental testing and space qualifications tests it is planned to do an astronomical experiment with a stratospheric balloon or a sounding rocket. The work is embedded in ACCASI („Aschaffenburg Competence Center for Astronomical and Space Instumentation“)
X-ray telescopes usually operate in space and are quite different from astronomical telescopes for visible light. For normal angles of incidence, optical light is reflected on the mirror surface, whereas X-rays are either transmitted or absorbed. However, also high reflectivity X-rays mirrors are possible, when the incident rays direction is almost parallel to the mirror surface. Such grazing incidence mirrors are usually coated with thin layers of precious metals like iridium, gold or platinum, as this result in high X-ray reflectivity. These noble metals offer a wide range of reflection up to high photon energies, but, due to a series of absorption edges, have low reflectivity in the 2 - 4 keV band and below. This contribution presents the development of innovative material combinations based on thin layers of iridium and chromium, followed by an additional layer of carbon-based materials. We also discuss corresponding production methods (like dip coating) for enhanced reflectivity mirror coatings of future X-ray telescopes.
Recent progress in nanosatellite technologies allows to consider innovative new CubeSat missions for scientific purposes. We present and evaluate the design of a small and cost effective CubeSat mission to monitor lunar meteoroid impacts by detecting their optical flashes. The poster summarizes the results of a comprehensive survey of past and recent ground based and satellite based projects focussing on lunar impact monitoring and discusses important aspects of the proposed mission and various alternatives for their solutions. Several spacecraft orbits around Moon and their usefulness for lunar impact observation are studied. In addition, we discuss the environmental risks and challenges, which such spacecraft needs to face, mainly thermal management and radiation tolerance. Finally, we present and discuss the design an optical camera suitable to detect meteoroid impacts on the lunar surface.
With ground based optical telescopes astronomers observe celestial objects over a wide spectral range. As usually three or even more reflections at telescope mirrors are involved, good reflection properties of the mirror coatings are important. The aluminum evaporation technique has been - and is still - the standard solution for the reflective coatings of large astronomical mirrors. Such coatings have excellent reflectivity in the ultraviolet and in the visible, but perform poorly in the infrared. Silver is the metal having highest reflectivity for wavelengths longward of 400 nm, but isn´t the best choice for reflectivity in the ultraviolet and for blue light. To avoid degradation by oxidation, durable silver coatings need to be protected by transmitting overcoating layers. In the presented study, different metallic coatings – including unusual ones like sputtered iridium - are characterized to identify a coating that is most suitable for the spectral range from ultraviolet to infrared. Experimental results are compared to simulations based on the complex refractive indices of these materials. Thereby dependence of incidence angle and polarization is also considered.
The EU intends to restrict the use of critical fuels in space propulsion systems. These propellants like hydrazine are chemically aggressive, toxic and carcinogenic. Space propulsion of the future should be environmentally friendly, inexpensive, and easy to handle. Aschaffenburg University and DLR are currently developing environmentally friendly technologies for future satellite engines. Thereby rocket-grade hydrogen peroxide, which is foreseen as a substitute, is converted to uncritical water vapour and oxygen by an exothermic catalytic reaction on nanostructured iridium layers. The resulting hot gases provide the required amount of thrust. The iridium catalyst layers are coated onto ceramic pellets, using RF magnetron sputtering technology. The catalytic functionality was tested afterwards at the chemical laboratories of DLR. First experimental results show a significantly higher catalytic activity for nanostructured iridium surfaces than for smoother crystalline layers.
In the years 2016 to 2018 the Bavarian-Czech Academic Agency (BTHA) funded in summary four bilateral projects between
Aschaffenburg University and CVUT Prague: JEUMICO, TRILAMICO, JODEXRA, and AXROCO. The effective combination
of equipment, manpower, and know-how of both partners resulted in the development of stress-compensated iridium
coatings for astronomical X-ray mirrors. The findings have been published at scientific conferences and in joint papers. This
poster gives a review on the social , political and educational aspects of the collaborations in form of a photo documentation.