EMCCDs for space applications

This paper describes a qualification programme for Electron-Multiplication Charge Coupled Devices (EMCCDs) for use in space applications. While the presented results are generally applicable, the programme was carried out in the context of CCD development for the Radial Velocity Spectrometer (RVS) instrument on the European Space Agency's cornerstone Gaia mission. We discuss the issues of device radiation tolerance, charge transfer efficiency at low signal levels and life time effects on the electron-multiplication gain. The development of EMCCD technology to allow operation at longer wavelengths using high resistivity silicon, and the cryogenic characterisation of EMCCDs are also described

Food products for space applications

Specially-prepared foodstuffs supply an astronaut with a diet containing his basic nutritional requirements in a form that is useful in his enironment. Several edible coatings preserve foods and give loose foods form and firmness. These coatings aid in packaging and give the food slip for easy removal from the package

Power HBT reliability for space applications

High power HBT process developed by UMS for X-band application have been space evaluated under CNES and ESA funding.The reliability assessment plan features high temperatures storage tests,DC life-tests,RF step test stress,ESD and radiation tests.A set of evaluation test vehicles was defined for this purpose.Activation energy have been determined,failure rate calculations are in line with the space requirement

Mechanical suspensions for space applications

Characteristics of mechanical suspensions for moving components of aerospace system

SDIO robotics in space applications

Robotics in space supporting the Strategic Defense System (SDS) program is discussed. Ongoing initiatives which are intended to establish an initial Robotics in Space capability are addressed. This is specifically being referred to as the Satellite Servicing System (SSS). This system is based on the NASA Orbital Maneuvering Vehicle (OMV) with a Robotic Manipulator(s) based on the NASA Flight Telerobotic Servicer (FTS) and other SSS equipment required to do the satellite servicing work attached to the OMV. Specific Robotics in Space Requirements which have resulted from the completion of the Robotics Requirements Study Contract are addressed

Flexural pivots for space applications

Design and fabrication of flexible pivots for aerospace structure

Composite materials for space applications

The objectives of the program were to: generate mechanical, thermal, and physical property test data for as-fabricated advanced materials; design and fabricate an accelerated thermal cycling chamber; and determine the effect of thermal cycling on thermomechanical properties and dimensional stability of composites. In the current program, extensive mechanical and thermophysical property tests of various organic matrix, metal matrix, glass matrix, and carbon-carbon composites were conducted, and a reliable database was constructed for spacecraft material selection. Material property results for the majority of the as-fabricated composites were consistent with the predicted values, providing a measure of consolidation integrity attained during fabrication. To determine the effect of thermal cycling on mechanical properties, microcracking, and thermal expansion behavior, approximately 500 composite specimens were exposed to 10,000 cycles between -150 and +150 F. These specimens were placed in a large (18 cu ft work space) thermal cycling chamber that was specially designed and fabricated to simulate one year low earth orbital (LEO) thermal cycling in 20 days. With this rate of thermal cycling, this is the largest thermal cycling unit in the country. Material property measurements of the thermal cycled organic matrix composite laminate specimens exhibited less than 24 percent decrease in strength, whereas, the remaining materials exhibited less than 8 percent decrease in strength. The thermal expansion response of each of the thermal cycled specimens revealed significant reduction in hysteresis and residual strain, and the average CTE values were close to the predicted values

Wear-resistant ball bearings for space applications

Ball bearings for hostile environments were developed. They consist of normal ball bearing steel parts of which the rings are coated with hard, wear-resistant, chemical vapor deposited (C.V.D) TiC. Experiments in ultrahigh vacuum, using cages of various materials with self-lubricating properties, have shown that such bearings are suitable for space applications

Bio-inspired programmable matter for space applications

Nowadays, space structures are often designed to serve only a single objective during their mission life, examples are solar sails for propulsion, antennas for communication or shields for protection. By enabling a structure to change its shape and therefore adapt to different mission stages in a single structure, the flexibility of the spacecraft can be increased by greatly decreasing the mass of the entire system. The possibility to obtain such a structure lies in a cellular approach in which every cell is programmable to change its basic properties. The shape change of the global structure can be significantly by adding up these local changes, for example the cells length. An idea presented in this paper is to adapt these basic changeable elements from nature’s heliotropism. Heliotropism is the growth or movement of an organism towards the direction of the sunlight. By changing the turgor pressure between two adjacent cells in the plant’s stem, called motor cells, the stem of the plant flexes. Due to the simplicity of the principle, the movement through pressure change seems perfect for the application on deployable space structures. The design of the adaptive membrane consists of an array of cells which are inflated by employing residual air inflation. Residual air inflation uses the expansion of trapped air inside the structure when subjected to vacuum conditions to inflate the structure. A high packing efficiency and deployment reliability can be achieved by using this passive deployment technique coupled with a multiple unit membrane design. To imitate the turgor pressure change between the motor cells of the plants to space structures, piezoelectric micro pumps are added between two neighbouring cells. The smallest actuator unit in this assembly is therefore the two neighbouring cells and the connected micro pump. The cellular and multiple unit approach makes the structure highly scalable with countless application areas. This paper will outline the design idea and fabrication of the bio-inspired membrane and its application to space missions. Deployment simulations were undertaken in LS-DYNA™ and compared to bench test samples of vacuum inflating circular specimens. A model to control the local elements in order to obtain a desired global shape will be presented as well. The paper will conclude with an overview on the REXUS 13 sounding rocket experiment StrathSat-R which will deploy a prototype of the bio-inspired adaptive membrane in micro gravity in spring 2013

Microwave integrated circuits for space applications

Monolithic microwave integrated circuits (MMIC), which incorporate all the elements of a microwave circuit on a single semiconductor substrate, offer the potential for drastic reductions in circuit weight and volume and increased reliability, all of which make many new concepts in electronic circuitry for space applications feasible, including phased array antennas. NASA has undertaken an extensive program aimed at development of MMICs for space applications. The first such circuits targeted for development were an extension of work in hybrid (discrete component) technology in support of the Advanced Communication Technology Satellite (ACTS). It focused on power amplifiers, receivers, and switches at ACTS frequencies. More recent work, however, focused on frequencies appropriate for other NASA programs and emphasizes advanced materials in an effort to enhance efficiency, power handling capability, and frequency of operation or noise figure to meet the requirements of space systems