Organic transformation of lignin into mussel-inspired glues: next-generation 2K adhesive for setting corals under saltwater

The 2-methoxyphenol units (G-units) in lignin are modified by demethylation and oxidation to provide the activated lignin as one part of an advanced biobased two-component (2K) adhesive system, which exhibits promising shear strengths in dry and underwater applications. The activation of lignin is straightforward and generates quinones via demethylation and periodate oxidation. These act as Michael acceptors and react smoothly with multi-thiol-star polymers to yield thiol-catechol connectivities (TCCs). The mussel-inspired material platform acts as a very robust and versatile adhesive, combining low-cost and readily available lignin with multi-thiols to achieve outstanding adhesion strengths of up to 15 MPa in dry application. In particular, the 2K system is compatible with the marine biological environment and shows no acute toxicity to sensitive organisms such as fish eggs. Thus, one possible application of this material could be an adhesive for setting temperature-resistant corals in damaged reefs.Peer Reviewe

Passive Interferometric Ocean Currents Observation Synthetic Aperture Radar (PICOSAR)

This paper describes PICOSAR (Passive Interferometric ocean Currents Observation Synthetic Aperture Radar), a concept consisting of two small, low-cost and low power spacecraft carrying a passive, receive-only SAR payload. PICOSAR enhances the functionality of a full SAR system such as Sentinel-1 or TerraSAR-X by adding a unique along-track interferometer dedicated to ocean surface current measurements. The passive nature of this system and the focus on a single application and single operation mode allows the implementation of PICOSAR using a very cost effective payload design and the use of a compact and low-cost micro-satellite bus. Besides the clear scientific value of PICOSAR, it would also foster the development of several key technologies: micro-satellite architectures, autonomous formation flying, and multi-static SAR constellations

Low Cost Mission to Deimos

The German non-profit amateur satellite organisation AMSAT-Deutschland successfully designed, built and launched four HEO satellites in the last three decades. Now they are going to build a satellite to leave the Earth orbit based on their flight-proven P3-D satellite design. Due to energetic constraints the most suitable launch date for the planned P5-A satellite to Mars will be in 2018. To efficiently use the relatively long time gap until launch a possible prior Moon mission came into mind. In co-operation with the DLR-Institute of Space Systems in Bremen, Germany, two studies on systems level for a first P5 satellite towards Moon and a following one towards Mars have been performed. By using the DLR’s Concurrent Engineering Facility (CEF) two consistent satellite concepts were designed including mission analysis, configuration, propulsion, subsystem dimensioning, payload selection, budgeting and cost. The present paper gives an insight in the accomplished design process and the results of the performed study towards Mars. The developed Mars orbiter is designed to carry the following four main instruments besides flexible communication abilities: -multispectral line scanner for Martian cloud investigations and Deimos (and Phobos) stereo pictures during close flybys -Deimos framing camera for high resolution pictures of Deimos (and Phobos) including video mode -sensor imaging infrared spectrometer for mineralogy of Martian (also Deimos and Phobos) silicates and surface temperature measurements -radio science for research of Deimos (& Phobos) gravity, profiling of Mars ionosphere, occurrence of third meteoritic ionosphere layer; sounding of neutral atmosphere; solar corona activity This study presents a non-industrial satellite concept that could be launched as piggyback load on Ariane 5 into GTO. It promises a low cost mission into a Mars orbit that allows close approaches to Deimos and Phobos

Image is everthing - Modern high resolution sensing satellites could be about to offer a valuable insight into traffic congestion around Europe

The use of modern high resolution remote sensing satellites can revolutionise traffic research in a global scale. Within an area of more than 4.000 km in diameter around each ground receiving station traffic-data can be received from the satellite, processed and disseminated to the user in near-real-time. With on-board data storage acquisitions from other parts of the world can be downloades to a ground station with the German radar satellite TerraSAR-X which shall be launched already in summer 2005

SAR Interferometry With TerraSAR-X

During the last decade, the techniques to generate digital elevation models (DEM) from SAR interferometry have been demonstrated and refined to a quasi-operational status using data from the ERS tandem mission. With this experience and an improved single-pass system concept, data from the Shuttle Radar Topography Mission (SRTM) acquired in 2000 have been used to produce a global DEM with unprecedented quality. However, under the extreme viewing conditions in mountainous terrain both ERS and SRTM suffer from or even fail due to the radar specific layover and shadow effect that leaves significant areas uncovered and poses severe problems to phase unwrapping. The paper quantifies the areas leading to layover and shadow, and shows innovative ways to overcome shadow and improve phase unwrapping in general

Germany's Option for a Moon Satellite

The German non-profit amateur satellite organisation AMSAT-Deutschland successfully designed, built and launched four HEO satellites in the last three decades. Now they are going to build a satellite to leave the Earth orbit based on their flight-proven P3-D satellite design. Due to energetic constraints the most suitable launch date for the planned P5-A satellite to Mars will be in 2018. To efficiently use the relatively long time gap until launch a possible prior Moon mission came into mind. In co-operation with the DLR-Institute of Space Systems in Bremen, Germany, two studies on systems level for a first P5 satellite towards Moon and a following one towards Mars have been performed. By using the DLR’s Concurrent Engineering Facility (CEF) two consistent satellite concepts were designed including mission analysis, configuration, propulsion, subsystem dimensioning, payload selection, budgeting and cost. The present paper gives an insight in the accomplished design process and the results of the performed study towards Moon. The developed Moon orbiter is designed to carry the following four main instruments besides flexible communication abilities: -slewable HDTV camera combined with a high gain antenna that allows receiving lunar television using a commercially available satellite TV dish on Earth -sensor imaging infrared spectrometer for mineralogy of lunar silicates and lunar surface temperature measurements -camera for detection and monitoring of impact flashes in visible light (VIS) on lunar night side caused by meteoroid impact events -camera technology test for interplanetary navigation and planetary approach navigation. This study presents a non-industrial satellite concept that could be launched as piggyback load on Ariane 5 into GTO. Due to the fact, that the satellite would be built by the private sector, the mission costs would remain low. Otherwise the scientific and public output would be high using that satellite bus for the instruments contributed by DLR