Space automation and robotics activities past, present and future: Next steps for a robotics laboratory
An Automation and Robotics (A&R) laboratory is being developed at the National Aerospace Laboratory NLR. The laboratory is intended to be a testbed for harmonized ESA/Dutch operations technology. A number of activities related to (internal) A&R are reviewed. A reference scenario involving liquid sloshing experiments based on an external robot arm is analysed to suggest next steps for further developments. Remote utilization of robotics technology is emphasised.
Introduction to possible means of experiment operations on the space station
The present plans for space stations are evolutionary developments from Skylab, ASTP, Spacelab, and recently, MIR. Other forbears can be identified as well, and it is instructive to compare current designs with the drawings that appeared in magazines around 1950, when spaceflight first appeared feasible. The space station that is taken as the basis for the present report, is the complex that is to be realized in consequence of a political decision of the USA, Discussions between NASA, ESA and the Japanese are to determine the extent of a major International cooperation in this venture. Both in Europe (Columbus) and in Japan original designs exist, and plans independent of the USA have been mooted. The economic conditions of the partners have changed sufficiently since the beginning of the negotations that scope for reassessment of shares may exist. An important use of the space station is for scientific purposes. As such it can be likened to a multi-user facility, an institution with many representatives on earth. Thus, the scientific operation of the space station can be modelled after different examples. A capability explored on Spacelab Is the investigation of physical systems in mlcrogravlty. The effect of gravity on heat and mass transfer processes Is often profound and, because these processes are so ubiquitous, may have important applications in processing technology. The report is to clarify some attributes of the space station that are relevant to its realization. The choices of organisation structure and engineering paradigms have economic consequences. It is hoped that, as a corollary, promising workpackages can be identified for particular national or institutional capabilities.
Stability of planar PEMFC in Printed Circuit Board technology
Abstract The use of planar PEMFCs in printed circuit board (PCB) technology with a thickness of less than 3.5 mm are presented. This planar design consists of an open cathode side which allows a completely passive, self-breathing operation of the fuel cell. Power densities of 100 mW/cm 2 at 500 mV with hydrogen as a fuel were achieved. A steady operation with this type of fuel cell was demonstrated over a week without any cell flooding. Since the electrical conducting elements of PCBs usually are made of copper, corrosion in the wet environment of a PEMFC is expected. Thus, a significant degradation in performance of fuel cells made of plain copper PCBs was seen in long-term operation. In order to avoid corrosion, the copper layer has to be coated. Fuel cells in PCB design with diverse coatings were tested in long-term operations up to 1000 h under load. Moreover, corrosion currents have been determined by the use of potentiodynamic scans. Promising coatings are electroplated Cr and Ni and a combination of Ni/Au.