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NASA Team Proposes Laser for Orbital Debris Tracking

Barry Coyle and Paul Stysley, laser researchers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, want to develop a method to define and track orbital debris using laser ranging — a promising approach that could overcome shortfalls with passive optical and radar techniques, which debris trackers use today to locate and track dead satellites, spacecraft components, and other remnants orbiting in low-Earth or geosynchronous orbits where most space assets reside.Inspired by an Australian study that found laser tracking increased the accuracy of debris ranging by a factor of 10 when compared with other methods, Coyle and Stysley now "want to reproduce the results from this paper on a larger scale," using Goddard’s Geophysical and Astronomical Observatory (GGAO). The GGAO satellite laser-ranging team, led by Goddard’s Jan McGarry, has advanced laser-ranging techniques using satellites equipped with retro-reflectors, becoming world leaders in the field.GGAO’s 48-inch telescope, which transmits outgoing and receives incoming laser beams, was built in the early 1970s as a research and development and testing facility for laser ranging, lidar, and astronomical instruments. The facility has ranged to spacecraft at planetary distances and has been used to provide on-orbit calibration of some of Goddard’s altimetry spacecraft. NASA also used the facility in 2005 to determine the performance of the laser-altimeter instrument aboard its MESSENGER spacecraft as it flew past Earth during its sojourn to Mercury.Once the team demonstrates ranging with a target not equipped with the retro-reflector, it would like to implement the technique in a global network of ground-based laser observatories to observe and more accurately track debris, thus aiding the world’s current debris-tracking efforts.Although it’s difficult removing the material itself, NASA mission operators can minimize its impact on operational space assets. They can move non-operational spacecraft to less populated orbits to remove the threat to new missions or allow dead craft to re-enter the atmosphere, where they burn up upon entry. What’s essential is that these assets are tracked and monitored to protect active and future missions from potentially harmful collisions, Coyle said.SourceAlso: Learn about a Debris & Ice Mapping Analysis Tool.

Posted in: Photonics, Lasers & Laser Systems, Aerospace, RF & Microwave Electronics, News

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Biomimetic Photodetector “Sees” in Color

Rice University researchers have created a CMOS-compatible, biomimetic color photodetector that directly responds to red, green, and blue light in much the same way the human eye does. The new device uses an aluminum grating that can be added to silicon photodetectors with CMOS technology.

Posted in: Electronics & Computers, Photonics, Sensors, Detectors, News

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'Cloaking' Device Uses Ordinary Lenses to Hide Objects

Inspired perhaps by Harry Potter’s invisibility cloak, scientists have recently developed several ways to hide objects from view. The latest effort, begun at the University of Rochester, not only overcomes some of the limitations of previous devices, but also uses inexpensive, readily available materials in a novel configuration.Forgoing specialized components, John Howell, a professor of physics at the University of Rochester, and graduate student Joseph Choi developed a combination of four standard lenses that keeps the object hidden as the viewer moves up to several degrees away from the optimal viewing position.“This is the first device that we know of that can do three-dimensional, continuously multidirectional cloaking, which works for transmitting rays in the visible spectrum,” said Choi, a PhD student at Rochester’s Institute of Optics.While their device is not quite like Harry Potter’s invisibility cloak, Howell had some thoughts about potential applications, including using cloaking to effectively let a surgeon “look through his hands to what he is actually operating on." The same principles could be applied to a truck to allow drivers to see through blind spots on their vehicles. SourceAlso: Learn about ELID Grinding of Large Aspheres.

Posted in: Photonics, Optics, Surgical Robotics/Instruments, Medical, Transportation, Automotive, News

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Researchers Equip Robot with Novel Tactile Sensor

Researchers at MIT and Northeastern University have equipped a robot with a novel tactile sensor that lets it grasp a USB cable draped freely over a hook and insert it into a USB port.The sensor is an adaptation of a technology called GelSight, which was developed by the lab of Edward Adelson, the John and Dorothy Wilson Professor of Vision Science at MIT, and first described in 2009. The new sensor isn’t as sensitive as the original GelSight sensor, which could resolve details on the micrometer scale. But it’s smaller — small enough to fit on a robot’s gripper — and its processing algorithm is faster, so it can give the robot feedback in real time.A GelSight sensor — both the original and the new, robot-mounted version — consists of a slab of transparent, synthetic rubber coated on one side with a metallic paint. The rubber conforms to any object it’s pressed against, and the metallic paint evens out the light-reflective properties of diverse materials, making it much easier to make precise optical measurements.In the new device, the gel is mounted in a cubic plastic housing, with just the paint-covered face exposed. The four walls of the cube adjacent to the sensor face are translucent, and each conducts a different color of light — red, green, blue, or white — emitted by light-emitting diodes at the opposite end of the cube. When the gel is deformed, light bounces off of the metallic paint and is captured by a camera mounted on the same cube face as the diodes.From the different intensities of the different-colored light, the algorithms developed by Adelson’s team can infer the three-dimensional structure of ridges or depressions of the surface against which the sensor is pressed. Source Read other Sensors tech briefs.

Posted in: Photonics, Optics, Materials, Motion Control, Sensors, Lighting, LEDs, Machinery & Automation, Robotics, News

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New Laser Technology to Make 2020 Mission to Mars

NASA announced recently that laser technology originally developed at Los Alamos National Laboratory has been selected for its new Mars mission in 2020. SuperCam, which builds upon the successful capabilities demonstrated aboard the Curiosity Rover during NASA’s current Mars Mission, will allow researchers to sample rocks and other targets from a distance using a laser.

Posted in: Electronics & Computers, Electronics, Imaging, Photonics, Lasers & Laser Systems, Sensors, Detectors, Test & Measurement, Measuring Instruments, Aerospace, Machinery & Automation, News

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Secret of Eumelanin’s Ability to Absorb Broad Spectrum of Light Uncovered

Melanin — and specifically, the form called eumelanin — is the primary pigment that gives humans the coloring of their skin, hair, and eyes. It protects the body from the hazards of ultraviolet and other radiation that can damage cells and lead to skin cancer. But the exact reason why the compound is so effective at blocking such a broad spectrum of sunlight has remained something of a mystery. Now, however, researchers at MIT and other institutions have solved that mystery, potentially opening the way for the development of synthetic materials that could have similar light-blocking properties.

Posted in: Electronics & Computers, Photonics, Optics, Materials, Composites, Medical, Solar Power, Energy, News

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NASA Engineer Set to Complete First 3D-Printed Space Cameras

By the end of September, NASA aerospace engineer Jason Budinoff is expected to complete the first imaging telescopes ever assembled almost exclusively from 3D-manufactured components.Under his multi-pronged project, funded by Goddard’s Internal Research and Development (IRAD) program, Budinoff is building a fully functional, 50-millimeter (2-inch) camera whose outer tube, baffles and optical mounts are all printed as a single structure. The instrument is appropriately sized for a CubeSat, a tiny satellite comprised of individual units each about four inches on a side. The instrument will be equipped with conventionally fabricated mirrors and glass lenses and will undergo vibration and thermal-vacuum testing next year.Budinoff also is assembling a 350-millimeter (14-inch) dual-channel telescope whose size is more representative of a typical space telescope.Should he prove the approach, Budinoff said NASA scientists would benefit enormously — particularly those interested in building infrared-sensing instruments, which typically operate at super-cold temperatures to gather the infrared light that can be easily overwhelmed by instrument-generated heat. Often, these instruments are made of different materials. However, if all the instrument’s components, including the mirrors, were made of aluminum, then many of the separate parts could be 3D printed as single structures, reducing the parts count and material mismatch. This would decrease the number of interfaces and increase the instrument’s stability.SourceAlso: Learn about an Image Processing Method To Determine Dust Optical Density.

Posted in: Cameras, Imaging, Photonics, Optics, Manufacturing & Prototyping, Rapid Prototyping & Tooling, Aerospace, RF & Microwave Electronics, News

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