Search NASA⌕ Search

SEARCH · Search NASA

Results for “Redirect”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

The Asteroid Redirect Mission (ARM)

To achieve its long-term goal of sending humans to Mars, the National Aeronautics and Space Administration (NASA) plans to proceed in a series of incrementally more complex human spaceflight missions. Today, human flight experience extends only to Low-Earth Orbit (LEO), and should problems arise during a mission, the crew can return to Earth in a matter of minutes to hours. The next logical step for human spaceflight is to gain flight experience in the vicinity of the Moon. These cis-lunar missions provide a "proving ground" for the testing of systems and operations while still accommodating an emergency return path to the Earth that would last only several days. Cis-lunar mission experience will be essential for more ambitious human missions beyond the Earth- Moon system, which will require weeks, months, or even years of transit time.

Abell, P. A.↗
NASA NTRS2017

Design Study for the Asteroid Redirect Vehicle (ARV) Composite Primary Bulkhead

A design study was undertaken of a carbon fiber primary bulkhead for a large solar electric propulsion (SEP) spacecraft. The bulkhead design, supporting up to 16 t of xenon propellant, progressed from one consisting of many simple parts with many complex joints, to one consisting of a few complex parts with a few simple joints. The unique capabilities of composites led to a topology that transitioned loads from bending to in-plane tension and shear, with low part count. This significantly improved bulkhead manufacturability, cost, and mass. The stiffness-driven structure utilized high-modulus M55J fiber unidirectional prepregs. A full-scale engineering demonstration unit (EDU) of the concept was used to demonstrate manufacturability of the concept. Actual labor data was obtained, which could be extrapolated to a full bulkhead. The effort demonstrated the practicality of using high-modulus fiber (HMF) composites for unique shape topologies that minimize mass and cost. The lessons are applicable to primary and secondary aerospace structures that are stiffness driven.

Cressman, Thomas O.↗
NASA NTRS2019

NEXT Ion Propulsion System Risk Mitigation Tests in Support of the Double Asteroid Redirection Test Mission

Risk mitigation tests have been conducted by the NASA Glenn Research Center and The Aerospace Corporation in support of the DART Mission. The tests focused on NEXT performance characterizations intended to ensure its operations and characteristics are compatible with the DART mission operations, and to assist in the definition of the propulsion system. Tests were performed at the Aerospace Corporation and they involved: flow sensitivity-analyses, steady-state performance characterizations, and measurements of thruster erosion. The tests also involved defining, demonstrating, verifying, and evaluating the start-up sequences and a beam current regulation algorithm consistent with DART mission requirements. It was found that NEXT thruster operations are compatible with the proposed relaxation of flow control ranges for ignition and for steady-state operation.

Thomas, Robert E.↗
NASA NTRS2019

NEXT Single String Integration Tests in Support of the Double Asteroid Redirection Test Mission

A system integration test has been performed utilizing a prototype model NEXT ion thruster, an engineering model power processing unit, and a laboratory model command and data handling system. The objectives of the test were to: a) verify that the integrated system meets performance requirements, b) demonstrate that the integrated system is functional across the anticipated thermal, power processor, and Xe propellant ranges for the DART mission, and to c) evaluate fault detection and operation of the command and data handling system. Measurements made during this test included: thruster performance, PPU input voltages, PPU electrical and thermal telemetry, software states, and fault flags. Additionally, a far-field electrostatic probe diagnostic was used to infer relative changes in the thrust vector across the various propellant flow splits. This manuscript presents the results of these tests, which include integrated ion propulsion system demonstrations of performance, details on the execution of DART flight algorithms, and software fault handling.

Thomas, Robert E.↗
NASA NTRS2019

NEXT Single String Integration Tests in Support of the Double Asteroid Redirection Test Mission

A system integration test has been performed utilizing a prototype model NEXT ion thruster, an engineering model power processing unit, and a laboratory model command and data handling system. The objectives of the test were to: a) verify that the integrated system meets performance requirements, b) demonstrate that the integrated system is functional across the anticipated thermal, power processor, and Xe propellant ranges for the DART mission, and to c) evaluate fault detection and operation of the command and data handling system. Measurements made during this test included: thruster performance, PPU input voltages, PPU electrical and thermal telemetry, software states, and fault flags. Additionally, a far-field electrostatic probe diagnostic was used to infer relative changes in the thrust vector across the various propellant flow splits. This manuscript presents the results of these tests, which include integrated ion propulsion system demonstrations of performance, details on the execution of DART flight algorithms, and software fault handling.

Thomas, Robert↗
NASA NTRS2019

NEXT Ion Propulsion System Risk Mitigation Tests in Support of the Double Asteroid Redirection Test Mission

Risk mitigation tests have been conducted by the NASA Glenn Research Center and The Aerospace Corporation in support of the DART Mission. The tests focused on NEXT performance characterizations intended to ensure its operations and characteristics are compatible with the DART mission operations, and to assist in the definition of the propulsion system. Tests were performed at the Aerospace Corporation and they involved: flow sensitivity-analyses, steady-state performance characterizations, and measurements of thruster erosion. The tests also involved defining, demonstrating, verifying, and evaluating the start-up sequences and a beam current regulation algorithm consistent with DART mission requirements. It was found that NEXT thruster operations are compatible with the proposed relaxation of flow control ranges for ignition and for steady-state operation.

Thomas, Robert E.↗
NASA NTRS2019

NEXT Ion Propulsion System Risk Mitigation Tests in Support of the Double Asteroid Redirection Test Mission

Risk mitigation tests have been conducted by the NASA Glenn Research Center and The Aerospace Corporation in support of the DART Mission. The tests focused on NEXT performance characterizations intended to ensure its operations and characteristics are compatible with the DART mission operations, and to assist in the definition of the propulsion system. Tests were performed at the Aerospace Corporation and they involved: flow sensitivity-analyses, steady-state performance characterizations, and measurements of thruster erosion. The tests also involved defining, demonstrating, verifying, and evaluating the start-up sequences and a beam current regulation algorithm consistent with DART mission requirements. It was found that NEXT thruster operations are compatible with the proposed relaxation of flow control ranges for ignition and for steady-state operation.

Thomas, Robert E.↗
DOE OSTI2020

Redirecting data to improve page locality in a scalable data fabric

A data processing system includes a host processor, a local memory coupled to the host processor, a plurality of remote memory media, and a scalable data fabric coupled to the host processor and to the plurality of remote memory media. The scalable data fabric includes a filter for storing information indicating a location of data that is stored by the data processing system. The host processor includes a hardware sequencer coupled to the filter for selectively moving data stored by the filter to the local memory.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2020

Experimental demonstration and performance evaluation of a complex fenestration system for daylighting and thermal harvesting

Two significant design strategies for mitigating building energy consumption are daylight redirection and solar energy harvesting. Effective daylighting implementation enhances the amount of useful natural light within a space and offsets the need for electric lighting. Solar energy harvesting systems can mitigate energy costs from mechanical systems by managing incoming thermal loads or capturing solar energy that can be used to supplement thermal systems in the building. While there are many available façade-based technologies that can perform daylighting or solar thermal energy harvesting, there remains a limitation in available systems that can perform both of them simultaneously. This paper, describes the design and experimental demonstration of a Liquid Filled Prismatic Louver (LFPL) system, which combines both energy-saving strategies. The LFPL system was installed in a south-facing room in New York City and evaluated for indoor daylight penetration and potential for thermal energy harvesting. Daylight redirection is achieved through the prismatic louver geometry and proper orientation, whereas thermal energy harvesting is achieved through IR absorption from the liquid (e.g., water) within the prisms. Daylighting performance was evaluated by illuminance measurements at key locations within the space, whereas thermal harvesting performance was evaluated through temperature measurements and thermal imaging analysis. We show that the LFPL system, with all prismatic elements oriented at the same angle, achieve a 2-fold and 8-fold enhancement in daylight redirection to the ceiling, for prism orientations of 10° and 20°, respectively. We also demonstrate the system’s capability to adjust to specific lighting needs, within the space, through the dynamic individual orientation of prismatic elements; thus, achieving a concentrated ceiling illuminance enhancement of ~100 times and ~200 times at 2.5 and 4.3 m away from the window sill, providing workplane illuminance enhancement of 6 and 2 times more than in the case of the control room with regular windows. Furthermore, we illustrate a reduction of potential heating loads at locations close to the window from the combination of infrared absorption in the water volume and the redirection of the incoming solar radiation, leading to a reduction of the workplane temperature by an average of 7–10 °C.

14 SOLAR ENERGY↗
NASA NTRS1975

Attention and its role in the operator's work

A complex attentiometer investigation of the distribution, redirection, and concentration of attention during an operator's work notes the following stages: (1) General attentiveness is still not adequately expressed in the beginning; and (2) operator self-control of actions develops and gradually decreases errors in redirecting and distributing attention. A definite relationship is found between the improvement of concentration, distribution and redirection of attention and automation of sensorimotor performance. Excercises prove less effective in redirection of attention.

Shvetsov, O. P.↗
NASA NTRS2010

Fine alignment of a large segmented mirror

A system for aligning a segmented mirror includes a source of radiation directed along a first axis to the segmented mirror and a beamsplitter removably inserted along the first axis for redirecting radiation from the first axis to a second axis, substantially perpendicular to the first axis. An imaging array is positioned along the second axis for imaging the redirected radiation, and a knife-edge configured for cutting the redirected radiation is serially positioned to occlude and not occlude the redirected radiation, effectively providing a variable radiation pattern detected by the imaging array for aligning the segmented mirror.

Dey, Thomas William↗