277,300 research outputs found
Paper Session I-A - Development of Modular Replacement Instruments to Maximize the Science Return of Hubble Space Telescope (HST)
The Hubble Space Telescope science return has been and will continue to be improved through regular shuttle servicing missions which replace first generation science instruments with advanced design second and third generation instruments. Orders of magnitude improvement in science return per dollar comes primarily from incorporation of state of the art 1/100 wave optics such as were used on Corrective Optics Space Telescope Axial Replacement (COSTAR) to fix Hubbies vision and from large area Charge Coupled Device (CCD) and Multi Anode MicroChannel Array (MAMA) detectors that enable hundreds of times more spectral and/or spatial coverage of the sky with approximately the same sensitivity
Configurable 3D-integrated focal-plane sensor-processor array architecture
A mixed-signal Cellular Visual Microprocessor architecture with digital processors is
described. An ASIC implementation is also demonstrated. The architecture is composed of a
regular sensor readout circuit array, prepared for 3D face-to-face type integration, and one or
several cascaded array of mainly identical (SIMD) processing elements. The individual array
elements derived from the same general HDL description and could be of different in size, aspect
ratio, and computing resources
Autonomous Deployment of a Solar Panel Using an Elastic Origami and Distributed Shape Memory Polymer Actuators
Deployable mechanical systems such as space solar panels rely on the
intricate stowage of passive modules, and sophisticated deployment using a
network of motorized actuators. As a result, a significant portion of the
stowed mass and volume are occupied by these support systems. An autonomous
solar panel array deployed using the inherent material behavior remains
elusive. In this work, we develop an autonomous self-deploying solar panel
array that is programmed to activate in response to changes in the surrounding
temperature. We study an elastic "flasher" origami sheet embedded in a circle
of scissor mechanisms, both printed with shape memory polymers. The scissor
mechanisms are optimized to provide the maximum expansion ratio while
delivering the necessary force for deployment. The origami sheet is also
optimized to carry the maximum number of solar panels given space constraints.
We show how the folding of the "flasher" origami exhibits a bifurcation
behavior resulting in either a cone or disk shape both numerically and in
experiments. A folding strategy is devised to avoid the undesired cone shape.
The resulting design is entirely 3D printed, achieves an expansion ratio of
1000% in under 40 seconds, and shows excellent agreement with simulation
prediction both in the stowed and deployed configurations.Comment: 12 pages, 12 figure
Digital implementation of the cellular sensor-computers
Two different kinds of cellular sensor-processor architectures are used nowadays in various
applications. The first is the traditional sensor-processor architecture, where the sensor and the
processor arrays are mapped into each other. The second is the foveal architecture, in which a
small active fovea is navigating in a large sensor array. This second architecture is introduced
and compared here. Both of these architectures can be implemented with analog and digital
processor arrays. The efficiency of the different implementation types, depending on the used
CMOS technology, is analyzed. It turned out, that the finer the technology is, the better to use
digital implementation rather than analog
- âŠ