Browse Topic: Gravity
This paper proposes a nonlinear observer for the estimation of gravity vector and angles with respect to velocity vector (flight path angle, bank angle) of a high-performance aircraft. The technique is computationally simpler than the extended Kalman filter (EKF) and hence is suitable for onboard implementations when the digital flight control computer (DFCC) has computational burdens. Flight test data of a highly maneuvering flight such as wind-up turns and full rolls have been used to validate the technique.
Large amounts of existing space debris pose a threat to satellites, space vehicles, and astronauts aboard those vehicles. However, cleaning up the debris is problematic. For example, suction cups don't work in a vacuum, and traditional sticky substances like tape are largely useless because the chemicals they rely on can't withstand extreme temperature swings.
NASA has long recognized the difficulty in providing emergency medical care to astronauts in space. Many aspects of space travel make medical care inherently difficult, and sufficient storage space for medical equipment severely limits the ability to carry a full complement of diagnostic and therapeutic equipment onboard. The Microgravity Compatible Medical Suction Device (MCMSD) enables aspiration and containment of bodily fluids and vomitus, while preventing the transmission of infectious agents.
A stay on the International Space Station is no vacation. During a visit to the orbiting National Laboratory, astronauts divide their time among a variety of tasks. For one, they look after a multitude of space-based science experiments. For another, they clean and check the station’s equipment—inside and out. They also spend a significant amount of time doing something you might not expect: exercising.
In order to detect and quantify bone-specific alkaline phosphatase (BAP) in a human biological sample, a binding agent (molecule) that specifically recognizes BAP in a sample is typically required. This binding agent can then be used in numerous assays/instruments to enable the detection and quantification of BAP.
Objects that orbit the Earth, such as the International Space Station (ISS), provide a unique environment called zero-g, or more correctly, microgravity. All objects in orbit are pulled by Earth’s gravity, but they achieve the lack of gravity when they move at just the right speed (in the case of the ISS, around 17,500 miles per hour) so that the curve of their fall matches the curve of the Earth. The result is a perpetual freefall, creating weightlessness.
Future manned spacecraft and lunar or Mars outposts will need a condensing heat exchanger (CHX) to control humidity in the cabin atmosphere. Condensing surfaces must be hydrophilic to control condensate flow and ensure efficient operation in zero gravity, and biocidal to prevent growth of microbes and formation of biofilms on condensing surfaces. Coatings must be extremely stable, adhere to the condensing surface, and maintain hydro philic and biocidal properties for many years.
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