Leopold Summerer - Academia.edu (original) (raw)

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Papers by Leopold Summerer

JBIS, 2006

The paper presents the prospective roles of SPS concepts for Europe, shows the outcome of the stu... more The paper presents the prospective roles of SPS concepts for Europe, shows the outcome of the studies undertaken by ESA during the first phase of the European SPS Programme Plan and gives insight into the planned activities. These studies, performed by European industry and research centres in close cooperation with the ESA Advanced Concepts Team, were all directed towards the main goal of the first phase, the assessment of the principal validity and viability of solar power from space concepts in the light of advances in alternative sustainable, clean and potentially abundant solar based terrestrial concepts, taking into account expected changes in the European energy system (e.g. gradual introduction of hydrogen as energy vector). Special emphasis is given to the possibilities of integrating space and terrestrial solar plants. Depending on the timescale and geographic location considered, solar thermal options or solar photovoltaic options are more advantageous, the benefits of the later getting more attractive the further in the future the comparison and the greater the distance to the geographic equator. Laser and microwave power transmission is considered. While laser power transmission offer fundamental advantages for the integration into terrestrial solar power plants, the availability of existing ground receptions, power management and power distribution systems are also beneficial to the economics of the more efficient microwave systems. The relative proximity of good locations in the Sahara desert to the large European energy consumer market puts Europe in a special position regarding the integration of space and terrestrial solar power concepts. The papers presents a method to optimise such an integration, taking into account different possible orbital constellations, terrestrial locations, plant number and sizes as well as consumer profiles and extends the scope from the European-only to a multi continental approach including the fast growing Chinese electricity market. This work intends to contribute to the discussion on long-term options for the European commitment to durable CO2 emission reduction, which probably requires substantial changes in our energy system. Cleaner electricity generation and environmentally neutral transport fuels (e.g. solar generated hydrogen) are two major tools to reach this goal.

The Innovation, May 1, 2023

55th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law, Oct 4, 2004

European Physical Journal-special Topics, Oct 1, 2015

AbstractDevelopment of pulsed lasers for space-based science missions entail many additional chal... more AbstractDevelopment of pulsed lasers for space-based science missions entail many additional challenges compared to terrestrial experiments. For systems requiring short pulses ≪1 ns with energies >100 mJ and fast repetition rates >10 kHz there are currently few if no laser architectures capable of operating with high electrical efficiency >20% and have good system stability. The emergence of a mulit-channel fiber-based Coherent-Amplifying-Network or CAN laser potentially enables such capability for space based missions. Here in this article we present an analysis of two such missions scaling up in pulse energy from ≈100 mJ for a supercontinuum LIDAR application utilising atmospheric filamentation to the higher energy demands needed for space debris remediation requiring ≈10 J pulses. This scalability of the CAN laser provides pathways for development of the core science and technology where many new novel space applications can be made possible.

Astrophysics and space science proceedings, 2018

Bioinspiration & Biomimetics, Jul 29, 2021

Multi-junction solar cells constitute the main source of power for space applications. However, e... more Multi-junction solar cells constitute the main source of power for space applications. However, exposure of solar cells to the space radiation environment significantly degrades their performance across the mission lifetime. Here, we seek to improve the radiation hardness of the triple junction solar cell, GaInP/Ga(In)As/Ge, by decreasing the thickness of the more sensitive middle junction. Thin junctions facilitate the collection of minority carriers and show slower degradation due to defects. However, thinning the junction decreases the absorption, and consequently, the expected photocurrent. To compensate for this loss, we examined two bioinspired surface patterns that exhibit anti-reflective and light-trapping properties: (a) the moth-eye structure which enables vision in poorly illuminated environments and (b) the patterns of the hard cell of a unicellular photosynthetic micro-alga, the diatoms. We parametrize and optimize the biomimetic structures, aiming to maximize the absorbed light by the solar cell while achieving significant reduction in the middle junction thickness. The density of the radiation-induced defects is independent of the junction thickness, as we demonstrate using Monte Carlo simulations, allowing the direct comparison of different combinations of middle junction thicknesses and light trapping structures. We incorporate the radiation effects into the solar cell model as a decrease in minority carrier lifetime and an increase in surface recombination velocity, and we quantify the gain in efficiency for different combinations of junction thickness and the light-trapping structure at equal radiation damage. Solar cells with thin junctions compensated by the light-trapping structures offer a promising approach to improve solar cell radiation hardness and robustness, with up to 2% higher end-of-life efficiency than the commonly used configuration at high radiation exposure.

Elsevier eBooks, 2009

Among the most interesting fields in research are the emerging possibilities to interface the hum... more Among the most interesting fields in research are the emerging possibilities to interface the human brain directly with machines, eg with computers and robotic interfaces. The European Space Agency's Advanced Concept team as a multidisciplinary team from engineering, artificial ...

arXiv (Cornell University), Oct 7, 2022

Yearbook on space policy, 2017

Space as the discipline to demonstrate economic and political might and as military high ground h... more Space as the discipline to demonstrate economic and political might and as military high ground has pushed human ingenuity into developing new concepts and technologies for the exploration and use of this fourth ‘space’, following land-, sea- and air-spaces. Driven by governmental ambitions and means, space agencies have developed the technologies that have made this new space accessible (chemical rockets), technologies to navigate in it (electric, chemical, nuclear and direct solar propulsion, position and trajectory determination), and to use its resources (e.g. photovoltaic cells). In doing so they have created new markets served by new industries. Some of these have already transitioned from governmental to private sector driven markets, starting with telecom applications in the 1990s. Stimulated by U.S. policy decisions in the early 2000s, the private sector has entered virtually all space domains except deep space exploration. Against this background the present paper attempts to explore potentially game changing technologies for space applications.

57th International Astronautical Congress, Oct 2, 2006

The adoption of non-diffracting Bessel beams is proposed in this work to realize a near-field con... more The adoption of non-diffracting Bessel beams is proposed in this work to realize a near-field concentrator with high penetration depth, to be successfully integrated in drilling tools used for planetary surfaces exploration. The design, realization and test of a microwave Bessel beam launcher is discussed, and preliminary experimental results on analog rock materials are reported, which reveal beneficial effects for drilling operations.

Smart Materials for Opto-Electronic Applications

Microelectronics Reliability, 2021

Abstract Microprocessors are widely used in space applications. ARM processors fabricated with FD... more Abstract Microprocessors are widely used in space applications. ARM processors fabricated with FDSOI technologies are promising for future space programs. However, radiation-hardening approaches can greatly affect the resource overhead and performance. These hardening techniques need to be evaluated at system level to better understand their effectiveness, especially for modern CMOS technologies. In this paper, two ARM® Cortex® M0 cores, a reference core and a hardened core were implemented on the same die in a 28-nm FDSOI technology. The reference core was designed with components from the standard cell library, while the other one was implemented with hardened DICE flip-flops. Both of the cores shared the same on-chip TMR-protected SRAM. Heavy ion experiments showed that the error cross section of the core with DICE flip-flops was about 2 times smaller at LET of 40 MeV·cm2·mg−1. This suggests that the contribution from logic circuits in the microprocessor cores also need to be considered for better error reduction.

Concordia station in Antarctica is one of the most remote human outpost on Earth. Because of its ... more Concordia station in Antarctica is one of the most remote human outpost on Earth. Because of its geographical location, a winterover at Concordia shares a lot of stressors with a space mission. Following a recent study on the markers of sleep pressure during wakefulness on board of the International Space Station, we were investigating if long term isolation in a space analogue station shows similar effects on sleep pressure. Unlike in space, markers of sleep pressure did not increase during isolation’s constant darkness period in Antarctica. When measures of sleep pressure were high in the evening, psychological strain was increased, emphasising the importance of keeping sleep pressure under physiological levels during the mission. As a first indication for a countermeasure, we showed that one hour of bicycle exercise during lunch time could decrease sleep pressure. All these observations need to be further studied in a more controlled environment.