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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 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Stability and control of the Gossamer human powered aircraft by analysis and flight test

The slow flight speed, very light wing loading, and neutral stability of the Gossamer Condor and the Gossamer Albatross emphasized apparent-mass aerodynamic effects and unusual modes of motion response. These are analyzed, approximated, and discussed, and the resulting transfer functions and dynamic properties are summarized and compared. To verify these analytical models, flight tests were conducted with and electrically powered Gossamer Albatross II. Sensors were installed and their outputs were telemetered to records on the ground. Frequency sweeps of the various controls were made and the data were reduced to frequency domain measures. Results are given for the response of: pitch rate, airspeed and normal acceleration from canard-elevator deflection; roll rate and yaw rate from canard-rudder tilt; and roll rate and yaw rate from wing warp. The reliable data are compared with the analytical predictions.

Jex, H. R.↗
NASA NTRS1982

Development of a rotary instrumentation system, phase 2

A rotary instrumentation system which consists of ruggedized miniature telemetry transmitters installed on the rotating shaft of a gas turbine engine to telemeter the outputs of sensors (strain gages, thermocouples, etc.) on rotating engine components was designed. A small prototype system, which demonstrates the capabilities of performing in the intended environment and demonstrates that the system is expandable to handle about 100 data channels was developed.

Adler, A.↗
NASA NTRS1982

Telemetry system

The means of telemetering digital data from a spacecraft to the Deep Space Network is addressed. Phase shift keying and uncoded quadriphase shift keying modulations are discussed along with demodulation and decoding systems. Telemetry system losses and noisy reference performance for suppressed carrier receivers are also examined.

Yuen, J. H.↗
NASA NTRS1982

Spectroscopic imaging of the thermosphere from the Space Shuttle

The design features, performance characteristics, and intended missions for the Imaging Spectrometric Observatory scheduled to fly on the first Spacelab Shuttle mission in 1983 are described. The instrument comprises an array of five imaging spectrometers covering the spectral range 300-1200 A. The spectrometers operate simultaneously, using CCDs as collector elements. Resolution on the first flight will be limited to 3 A, with coverage to containing the dynamic range from nocturnal signals to the bright earth. A minicomputer in the Spacelab will permit crewmember interaction with the measurements, while data will be telemetered in real-time to a ground station. Initial mission objectives include observations of dayglow, nightglow, and twilightglow over the full wavelength range capability.

Torr, M. R.↗
NASA NTRS1984

Use of DBMS in Multi-step Information Systems for LANDSAT

Data are obtained by the thematic mapper on LANDSAT 4 in seven bands and are telemetered and electronically recorded at ground station where the data must be geometrically and rediometrically corrected before a photographic image is produced. Current system characteristics for processing this information are described including the menu for data products reports. The tracking system provides up-to-date and complete information and requires that production stages adhere to the inherent DBMS structure. The concept can be applied to any procedures requiring status information.

Noll, C. E.↗
NASA NTRS1984

Flight investigation of various control inputs intended for parameter estimation

An experiment assessing the stability and control derivatives resulting from various control inputs was undertaken using the F-8 digital fly by wire aircraft. Improved control inputs have been proposed as a means of making stability and contol derivative estimation more efficient, thus reducing the cost of flight testing and data analysis. The subject inputs were either generated by the pilot or preprogrammed in a remote ground computer and telemetered to the aircraft. Nine preprogrammed inputs and three pilot generated inputs were assessed at subsonic and supersonic flight conditions, and both unaugmented and highly augmented flight control systems were used. Effects of input amplitude were also assessed. The inputs were divided into two general types - sinusoidal or with corners (a rapid and distinct change in slope). The inputs with corners, performed in the unaugmented mode, produced the best sets of stability and control derivatives. The simplest of these inputs, the pilot generated doublet, produced sets of derivatives as good as those produced by the more complex inputs. Small inputs produced worse derivatives than the unaugmented mode, and sinusoidal inputs produced worse derivatives than corner containing inputs.

Shafer, M. F.↗
NASA NTRS1984

Spin dynamics and horizon sensor performance for the Solar Mesosphere Explorer

Numerical techniques for obtaining the trigger altitude of the Solar Mesosphere Explorer (SME) are detailed. The SME has a pair of fixed horizon sensors for attitude determination and initiation of the data acquisition procedures for measuring ozone concentrations at the limb. The spacecraft spin rate is calculated as each of the horizon sensors marks the limb with a pulse telemetered to the ground. A best fit spin dynamics model that takes into account the history of the satellite spin angle and all disturbances to the spin is described. Analyses show that the trigger altitude is calculated to an accuracy of 1.5-2.0 km. A significant indicator of the limb altitude is the stratospheric temperature at the 5 mb pressure level.

Lawrence, G. M.↗
NASA NTRS1986

CID-720 aircraft Langley Research Center preflight hardware tests: Development, flight acceptance and qualification

The testing conducted on LaRC-developed hardware for the controlled impact demonstration transport aircraft is discussed. To properly develop flight qualified crash systems, two environments were considered: the aircraft flight environment with the focus on vibration and temperature effects, and the crash environment with the long pulse shock effects. Also with the large quantity of fuel in the wing tanks the possibility of fire was considered to be a threat to data retrieval and thus fire tests were included in the development test process. The aircraft test successfully demonstrated the performance of the LaRC developed heat shields. Good telemetered data (S-band) was received during the impact and slide-out phase, and even after the aircraft came to rest. The two onboard DAS tape recorders were protected from the intense fire and high quality tape data was recovered. The complete photographic system performed as planned throughout the 40.0 sec of film supply. The four photo power distribution pallets remained in good condition and all ten onboard 16 mm high speed (400 frames/sec) cameras produced good film data.

Pride, J. D.↗
NASA NTRS1986

Lightning at Kennedy Space Center

Kennedy Space Center (KSC) is situated in an area that experiences one of the world's highest rates of cloud-ground lightning strikes, about 600-2000 strikes per summer. Two lightning detection systems have been implemented, the Launch Pad Lightning Warning System (LPLWS) and the Lightning Location and Protection system (LLP). The LPLWS consists of field mills of eight vertically oriented stator sections mounted 10 in. above ground and alternately covered and uncovered as the rotor turns. Differential voltages between covered and uncovered sections furnish electric field amplitude and polarity data. Ten samples per second are telemetered to a central processing facility. The system is used during launch and landing. The LLP has high and low gain components, the former being two direction finder antennas with 100 m strike position finding accuracy, the latter featuring medium gain antennas for 500 m accuracy in locating strikes. The LLP system is used primarily to warn personnel of strike conditions and to lift warnings to avoid lost work time. Several experimental programs have been initiated for triggering lightning strikes and controlling their locations.

Gibbons, W. C.↗
NASA NTRS1986

The necessity for a new parameterization of an empirical model for wind/ocean scatterometry

Difficulties related to the paucity of weather observation data regarding oceans were potentially alleviated for three summer months in 1978 when NASA's Seasat telemetered data from three wind-measuring instruments. The present study is concerned with one of these instruments, the Seasat A Scatterometer System (SASS). Attention is given to an internal consistency check of the SASS 1 model, comparisons of SASS 1 and other model-predicted winds with in situ winds, and a brief summary of the principal findings. It is found that a new wind retrieval system is required if SASS wind data are to be globally applicable and, at the same time, are to meet the required performance specifications. The sum-of-squares (SOS) technique for inverting SASS NRCS (normalized radar cross section) measurements results in the discarding of valuable data in low-speed areas and for higher incidence angles.

Woiceshyn, P. M.↗
NASA NTRS1985

Flight tests and preliminary aerodynamic parameter extraction of an externally piloted vehicle aircraft model

Model aircraft flight test investigations have been undertaken to develop a low cost flight data acquisition system and to evaluate aerodynamic parameter estimation techniques. The externally piloted vehicles (EPVs) used are instrumented with sensors measuring acceleration, angular rates, angles of attack and sideslip, flight path velocity, and control deflections. Measured state variables are downlink telemetered to a ground-based real time flight data acquisition system; the data thus recorded are used by flight test engineers and EPV pilots to monitor conditions and aid in piloting tasks. Attention is given to comparisons of F-16 EPV data with wind tunnel data.

White, E. R.↗
NASA NTRS1987

NASA Facts: How We Get Pictures from Space

The past 25 years of space travel and exploration has generated an unprecedented quantity of data from planetary systems. Images taken in space and telemetered back to Earth have greatly aided scientists in formulating better and more accurate theories about the nature and origin of out solar system. The procedures and spacecraft systems used to gather data are explained.

Haynes, Robert↗
NASA NTRS1986

Balloon gondola diagnostics package

In order to define a new gondola structural specification and to quantify the balloon termination environment, NASA developed a balloon gondola diagnostics package (GDP). This addition to the balloon flight train is comprised of a large array of electronic sensors employed to define the forces and accelerations imposed on a gondola during the termination event. These sensors include the following: a load cell, a three-axis accelerometer, two three-axis rate gyros, two magnetometers, and a two axis inclinometer. A transceiver couple allows the data to be telemetered across any in-line rotator to the gondola-mounted memory system. The GDP is commanded 'ON' just prior to parachute deployment in order to record the entire event.

Cantor, K. M.↗
NASA NTRS1986

Wright Brothers Lectureship in Aeronautics: Experience with HiMAT remotely piloted research vehicle - An alternate flight test approach

The highly maneuverable aircraft technology (HiMAT) program explored the various and complex interactions of advanced technologies, such as aeroelastic tailoring, close-coupled canard, and relaxed static stability. A 0.44-subscale remotely piloted research vehicle (RPRV) of a hypothetical fighter airplane was designed and flight-tested to determine the effects of these interactions and to define the design techniques appropriate for advanced fighter technologies. Flexibility and high maneuverability were provided by flight control laws implemented in ground-based computers and telemetered to the vehicle control system during flight tests. The high quality of the flight-measured data and their close correlation with the analytical design modeling proved that the RPRV is a viable and cost-effective tool for developing aerodynamic, structure, and control law requirements for highly maneuverable fighter airplanes of the future.

Deets, D. A.↗
NASA NTRS1987

Application of low-power, high-rate PCM telemetry in a helicopter instrumentation system

The use of low-power, high-rate pulse code modulation (PCM) in a helicopter instrumentation system is examined. A Helicopter Instrumentation and Recording System (HIARS) was developed to obtain main rotor blade measurements and fuselage performance measurements. The HIARS consists of a low-power PCM telemeter, a digital PCM system, an optical rotor position sensor, and a PCM decommutation unit; the components and functions of these subsystems are described. Flight tests were conducted to evaluate the ability of the HIARS to measure aircraft parameters. The test data reveal that the PCM telemetry is applicable to helicopter instrumentation systems.

Thomas, Mitchel E.↗
NASA NTRS1987

A high-resolution local network study of the Nazca plate Wadati-Benioff zone under western Argentina

Seismic data, recorded by INPRES telemetered network located above one of the subhorizontal segments of the subducted Nazca plate Wadati-Benioff zone beneath western Argentina, were analyzed to determine the zone's fine structure. The depth of the center and the thickness of the subhorizontal Wadati-Benioff zone beneath the network were calculated to be about 107 km and about 20 km, respectively, with most of the seismogenic zone concentrated in a region about 12 km thick. The Nazca plate is interpreted to be in a state of down-dip tension and to be decoupled from the overriding South American plate by a weak zone of asthenospheric or shear-heated material. The South American plate is estimated to be 80 km thick, based on the location of the subducted Nazca plate and an inferred decoupling zone between the plates.

Smalley, Robert F., Jr.↗
NASA NTRS1987

Strain-gage balance calibration of a magnetic suspension and balance system

A load calibration of the NASA 13-in magnetic suspension and balance system (MSBS) is described. The calibration procedure was originally intended to establish the empirical relationship between the coil currents and the external loads (forces and moments) applied to a magnetically suspended calibrator. However, it was discovered that the performance of a strain-gage balance is not affected when subjected to the magnetic environment of the MSBS. The use of strain-gage balances greatly reduces the effort required to perform a current-vs.-load calibration as external loads can be directly inferred from the balance outputs while a calibrator is suspended in MSBS. It is conceivable that in the future such a calibration could become unnecessary, since an even more important application for the use of a strain-gage balance in MSBS environment is the acquisition of precision aerodynamic force and moment data by telemetering the balance outputs from a suspended model/core/balance during wind tunnel tests.

Roberts, Paul W.↗
NASA NTRS1988

Acquisition and analysis of primate physiologic data for the Space Shuttle

This paper describes the design and prototypes of the Physiologic Acquisition and Telemetry System (PATS), which is a multichannel system, designed for large primates, for the data acquisition, telemetry, storage, and analysis of physiological data. PATS is expected to acquire data from units implanted in the abdominal cavities of rhesus monkeys that will be flown aboard the Spacelab. The system will telemeter both stored and real-time internal physiologic measurements to an external Flight Support Station (FSS) computer system. The implanted Data Acquition and Telemetry Subsystem subunit will be externally activated, controlled and reprogrammed from the FSS.

Eberhart, Russell C.↗