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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.

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

Fast Attitude Maneuvers for the Lunar Reconnaissance Orbiter

This paper describes a new operational capability for fast attitude maneuvering that is being developed for the Lunar Reconnaissance Orbiter (LRO). The LRO hosts seven scientific instruments. For some instruments, it is necessary to per-form large off-nadir slews to collect scientific data. The accessibility of off-nadir science targets has been limited by slew rates and/or occultation, thermal and power constraints along the standard slew path. The new fast maneuver (FastMan) algorithm employs a slew path that autonomously avoids constraint violations while simultaneously minimizing the slew time. The FastMan algo-rithm will open regions of observation that were not previously feasible and improve the overall science return for LRO's extended mission. The design of an example fast maneuver for LRO's Lunar Orbiter Laser Altimeter that reduc-es the slew time by nearly 40% is presented. Pre-flight, ground-test, end-to-end tests are also presented to demonstrate the readiness of FastMan. This pioneer-ing work is extensible and has potential to improve the science data collection return of other NASA spacecraft, especially those observatories in extended mission phases where new applications are proposed to expand their utility.

Karpenko, Mark↗
NASA NTRS2016

A Proposed Ascent Abort Flight Test for the Max Launch Abort System

The NASA Engineering and Safety Center initiated the Max Launch Abort System (MLAS) Project to investigate alternate crew escape system concepts that eliminate the conventional launch escape tower by integrating the escape system into an aerodynamic fairing that fully encapsulates the crew capsule and smoothly integrates with the launch vehicle. This paper proposes an ascent abort flight test for an all-propulsive towerless escape system concept that is actively controlled and sized to accommodate the Orion Crew Module. The goal of the flight test is to demonstrate a high dynamic pressure escape and to characterize jet interaction effects during operation of the attitude control thrusters at transonic and supersonic conditions. The flight-test vehicle is delivered to the required test conditions by a booster configuration selected to meet cost, manufacturability, and operability objectives. Data return is augmented through judicious design of the boost trajectory, which is optimized to obtain data at a range of relevant points, rather than just a single flight condition. Secondary flight objectives are included after the escape to obtain aerodynamic damping data for the crew module and to perform a high-altitude contingency deployment of the drogue parachutes. Both 3- and 6-degree-of-freedom trajectory simulation results are presented that establish concept feasibility, and a Monte Carlo uncertainty assessment is performed to provide confidence that test objectives can be met.

Tartabini, Paul V.↗
NASA NTRS1987

Independent Orbiter Assessment (IOA): Analysis of the reaction control system, volume 1

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results for the Reaction Control System (RCS). The purpose of the RCS is to provide thrust in and about the X, Y, Z axes for External Tank (ET) separation; orbit insertion maneuvers; orbit translation maneuvers; on-orbit attitude control; rendezvous; proximity operations (payload deploy and capture); deorbit maneuvers; and abort attitude control. The RCS is situated in three independent modules, one forward in the orbiter nose and one in each OMS/RCS pod. Each RCS module consists of the following subsystems: Helium Pressurization Subsystem; Propellant Storage and Distribution Subsystem; Thruster Subsystem; and Electrical Power Distribution and Control Subsystem. Of the failure modes analyzed, 307 could potentially result in a loss of life and/or loss of vehicle.

Burkemper, V. J.↗
NASA NTRS2018

Stationkeeping, Orbit Determination, and Attitude Control for Spacecraft in Near Rectilinear Halo Orbits

Final document is attached. From a Near Rectilinear Halo Orbit (NRHO), NASA's Gateway at the Moon is planned to serve as a proving ground and a staging location for human missions beyond Earth. Stationkeeping, Orbit Determination (OD), and attitude control are examined for uncrewed and crewed Gateway configurations. Orbit maintenance costs are investigated using finite maneuvers, considering skipped maneuvers and perturbations. OD analysis assesses DSN tracking and identifies OD challenges associated with the NRHO and crewed operations. The Gateway attitude profile is simulated to determine an effective equilibrium attitude. Attitude control propellant use and sizing of the required passive attitude control system are assessed.

Newman, Clark P.↗
NASA NTRS2018

Stationkeeping, Orbit Determination, and Attitude Control for Spacecraft in Near Rectilinear Halo Orbits

From a Near Rectilinear Halo Orbit (NRHO), NASA’s Gateway at the Moon is planned to serve as a proving ground and a staging location for human missions beyond Earth. Stationkeeping, Orbit Determination (OD), and attitude control are examined for uncrewed and crewed Gateway configurations. Orbit maintenance costs are investigated using finite maneuvers, considering skipped maneuvers and perturbations. OD analysis assesses DSN tracking and identifies OD challenges associated with the NRHO and crewed operations. The Gateway attitude profile is simulated to determine an effective equilibrium attitude. Attitude control propellant use and sizing of the required passive attitude control system are assessed.

Ryne, Mark S.↗
NASA NTRS1976

Multi-Satellite Attitude Prediction program/Orbiting Solar Observatory-8 (MSAP/OSO-8) operating guide

The sun's lower corona and chromosphere and their interaction in the X-ray and ultraviolet (UV) spectral regions were investigated to better understand the transport of energy from the photosphere to the corona. The interaction between the solar electromagnetic and particle radiation and the earth's environment was studied and the background component of cosmic X-rays was discussed.

Tate, V. H.↗
NASA NTRS1975

Mission operations and data systems

A communications system for performing the basic functions of mission operations, orbit and attitude determination, and data processing is described. A block diagram is provided to show the relationships of these functions with the spacecraft in orbit and the experiments to be conducted on board the spacecraft. Specific areas of application are discussed as follows: (1) software operating systems for the ATS-F satellite testing and ground support, (2) inversion of the RAE-1 satellite (Explorer 38 satellite) in orbit, (3) ALSEP differential Doppler tracking, (4) minitrack calibration using satellite data, (5) angles-only orbit extraction, and (6) image processing system performance prediction and product quality evaluation techniques. Block diagrams of the various systems are provided to show the steps involved in the operations.

Source record↗
NASA NTRS2013

DAWN'S Operations in Cruise from Vesta to Ceres

On 5 September 2012, Dawn concluded its successful exploration of Vesta, the second most massive object in the main asteroid belt. The spacecraft departed after 14 months in orbit and is now using its ion propulsion system to travel to dwarf planet Ceres, the most massive main-belt asteroid. The principal activity now is thrusting with the ion propulsion system to provide the 3.4 km/s required to rendezvous with Ceres early in 2015. Because two of the four reaction wheels have experienced faults and are likely unrecoverable, a substantial effort has been invested in preparing for Ceres operations with alternate attitude control methods. The project has engaged in an intensive campaign to reduce hydrazine expenditures, which has resulted in a significant increase in the hydrazine expected to be available for Ceres. Based on this work, studies provide good confidence that the required activities at Ceres can be completed. This paper describes post-Vesta operations, including measures taken to conserve hydrazine as well as other preparations for Ceres.

Dawn↗
NASA NTRS2013

Dawn's operations in cruise from Vesta to Ceres

On 5 September 2012, Dawn concluded its successful exploration of Vesta, the second most massive object in the main asteroid belt. The spacecraft departed after 14 months in orbit and is now using its ion propulsion system to travel to dwarf planet Ceres, the most massive main-belt asteroid. The principal activity now is thrusting with the ion propulsion system to provide the 3.3 km/s required to rendezvous with Ceres early in 2015. Because two of the four reaction wheels have experienced faults and are likely unrecoverable, a substantial effort has been invested in preparing for Ceres operations with alternate attitude control methods. The project has engaged in an intensive campaign to reduce hydrazine expenditures, which has resulted in a significant increase in the hydrazine expected to be available for Ceres. Based on this work, studies provide good confidence that the required activities at Ceres can be completed. This paper describes post-Vesta operations, including measures taken to conserve hydrazine as well as other preparations for Ceres.

Mase, Robert A.↗
NASA NTRS1973

Simulation of an experiment pointing system for the space shuttle

The pointing and control of experiments during sortie missions are examined from the standpoint of accuracy and performance. The effect of gimbal characteristics, pallet stiffness, and variation in the servo control loop are described. Simulation results are shown for a number of pointing options under the disturbing influences of man motion, thruster firings, and experiment operations. One option of particular interest is the suspended pallet which offers the possibility of high accuracy pointing of very large payloads without using conventional gimbals. The pallet is suspended within the payload bay by nonrigid attachments such as springs, thereby isolating experiments from most shuttle disturbances. Control moment gyros apply torques directly to the pallet to maintain pointing accuracy within the arc second range. Spring torques constrain shuttle attitude so thruster operation is not required. The suspended pallet approach will meet the base stability requirements of any sortie experiment and offers the possibility of a standardized low weight, low cost alternative to gimbaled mounts.

Nicaise, P. D.↗
NASA NTRS2003

Autonomous Telemetry Collection for Single-Processor Small Satellites

For the Space Technology 5 mission, which is being developed under NASA's New Millennium Program, a single spacecraft processor will be required to do on-board real-time computations and operations associated with attitude control, up-link and down-link communications, science data processing, solid-state recorder management, power switching and battery charge management, experiment data collection, health and status data collection, etc. Much of the health and status information is in analog form, and each of the analog signals must be routed to the input of an analog-to-digital converter, converted to digital form, and then stored in memory. If the micro-operations of the analog data collection process are implemented in software, the processor may use up a lot of time either waiting for the analog signal to settle, waiting for the analog-to-digital conversion to complete, or servicing a large number of high frequency interrupts. In order to off-load a very busy processor, the collection and digitization of all analog spacecraft health and status data will be done autonomously by a field-programmable gate array that can configure the analog signal chain, control the analog-to-digital converter, and store the converted data in memory.

Speer, Dave↗
NASA NTRS1987

Exploring flight crew behaviour

A programme of research into the determinants of flight crew performance in commercial and military aviation is described, along with limitations and advantages associated with the conduct of research in such settings. Preliminary results indicate significant relationships among personality factors, attitudes regarding flight operations, and crew performance. The potential theoretical and applied utility of the research and directions for further research are discussed.

NASA Discipline Space Human Factors↗
NASA NTRS1973

The evolution of the SEP stage /SEPS/ concept

The features of a solar electric propulsion (SEP) stage are examined. An SEP stage (SEPS) contains all of the subsystems required to deliver separable payloads to the desired target and to support its own operations. These include attitude control, communications, data handling, and computer subsystems in addition to the solar array and thrust subsystems required for electric propulsion. SEPS can provide subsystem support to attached payloads for comet flyby and asteroid rendezvous. It can accommodate both planetary and geosynchronous missions by the use of mission-peculiar modules. In addition SEPS can assist the shuttle tug transportation system in earth-orbital applications. Aspects of mission analysis are discussed together with details of the electric propulsion system including solar array considerations.

Gilbert, J.↗
NASA NTRS1977

V/STOL Conference, Palo Alto, Calif., June 6-8, 1977, Technical Papers

Papers are presented on practical aspects of commercial STOL operations, a Vertical Attitude Takeoff and Landing (VATOL) program, powered-lift STOL ground effects, conceptual design studies of Navy Type A V/STOL aircraft, and a V/STOL shaft propulsion system analytical performance model. Also considered are the management of swirling flows with application to wind tunnel design and V/STOL testing, flight control testing of the VAK-191B, and surface fluctuating pressure measurements on a 1/4-scale YC-14 boilerplate model.

Source record↗
NASA NTRS1987

Exploring flightcrew behaviour

A program of research into the determinants of flightcrew performance in commercial and military aviation is described, along with limitations and advantages associated with the conduct of research in such settings. Preliminary results indicate significant relationships among personality factors, attitudes regarding flight operations, and crew performance. The potential theoretical and applied utility of the research and directions for further research are discussed.

Helmreich, Robert L.↗