SEARCH · Engineering Papers
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.
Instrumentation system for nuclear experiments on scientific satellites allowing highest priority event selection during telemetry sequence and periodic change of priority order
Scientific satellites evolution during past decade and future development possibilities in conjunction with space shuttles and stations
Quality control and nondestructive testing for prevention of failures in scientific satellites
Objectives of investigators associated with multiple experiment scientific satellites
A reprogrammable data system aboard a small scientific satellite is described that samples and processes magnetospheric measurements for transmission to the ground. The lightweight configuration of the data system is made up of the program memory, data storage, input/output module, and a central processing unit. The system is designed for multiple missions.
The project and the missions of the Argentine scientific satellite, SAC-B, are summarized. SAC-B is an international cooperative project between NASA and the Secretariat of State of Science and Technology of the Argentine Republic. The objective of SAC-B is to advance the study of solar physics and astrophysics through the examination of solar flares, gamma ray burst sources and the diffuse soft X-ray cosmic background. The scientific payload comprises an instrument to measure the temporal evolution of X-ray emissions from solar flares as well as nonsolar gamma ray bursts, a combined soft X-ray and gamma ray burst detector, a diffuse X-ray background detector, and an energetic neutral atoms detector.
Design, development, integration, and testing of Small Scientific Satellites
Small Scientific Satellite program and first payload considerations
Magnetic attitude and spin control of small scientific satellite
Control of unmanned scientific satellites and unified tracking/command/telemetry at lunar distances
Principal investigator task evaluation, discussing responsibility for instruments, prelaunch operation, operational program establishment, processing, analyzing and publishing of results
An improved fast low-power-drain logic system has been developed for use in nuclear experiments on scientific satellites. The basic unit of the system is an AND-NAND gate which has a response in the 10-nsec range, a power drain of 2.0 mw and operates over the temperature range of -40 to +80 C. In addition to providing the AND-NAND logic functions, one or more of the basic units may be connected to yield a monostable pulse generator, a pulse generator proceeding an output pulse at the leading edge of the input pulse, a delay, a threshold detector, and a bistable circuit. The system requires relatively simple circuitry for interfacing at its outputs and inputs.
Closed loop, feedback verification techniques for command system of unmanned scientific satellite
This paper presents the capabilities implemented in the SAX system for an efficient operations management during its in-flight mission. SAX is an Italian scientific satellite for x-ray astronomy whose major mission objectives impose quite tight constraints on the implementation of both the space and ground segment. The most relevant mission characteristics require an operative lifetime of two years, performing scientific observations both in contact and in noncontact periods, with a low equatorial orbit supported by one ground station, so that only a few minutes of communications are available each orbit. This operational scenario determines the need to have a satellite capable of performing the scheduled mission automatically and reacting autonomously to contingency situations. The implementation approach of the on-board operations management, through which the necessary automation and autonomy are achieved, follows a hierarchical structure. This has been achieved adopting a distributed avionic architecture. Nine different on-board computers, in fact, constitute the on-board data management system. Each of them performs the local control and monitors its own functions while the system level control is performed at a higher level by the data handling applications software. The SAX on-board architecture provides the ground operators with different options of intervention by three classes of telecommands. The management of the scientific operations will be scheduled by the operation control center via dedicated operating plans. The SAX satellite flight mode is presently being integrated at Alenia Spazio premises in Turin for a launch scheduled for the end of 1995. Once in orbit, the SAX satellite will be subject to intensive check-out activities in order to verify the required mission performances. An overview of the envisaged procedure and of the necessary on-ground activities is therefore depicted as well.
Effects of CW and modulated interference on baseband of AM and FM demodulators used for control of unmanned scientific satellites
The following research work was accomplished: 1. We operated high throughput spectrophotometers and interferometers at eight observatories in the Arctic, Antarctic and mid-latitude regions to record relatively high-resolution spectra of very low light level airglow and auroral line as well as band emissions. 2. Our Polar observations of auroral emissions from N2 and O emissions have been analyzed to derive the O/N2 ratios around 110 km height in the Polar thermosphere during different auroral events triggered by the precipitation of auroral electrons with average energy of about 10 keV. These results have been compared with similar ratios derived from TIMED satellite s GUVI measurements of N2 LBH and 01 1356A emissions. 3. Our airglow measurements show MLT density and temperature modulations by Planetary, Tidal and Gravity Waves. They also indicate Mesopause cooling preceding a Stratospheric Warming Event (SWE).
Solar power system for the ariel satellite /uk-1/
Design of the united kingdom s-51 /uk-1/ ariel satellite solar power system