Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “TRACKING STATION”

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 1,153 records · Page 64
All sourcesNASA NTRSDOE OSTI
NASA NTRS2014

Comparing On-Orbit and Ground Performance for an S-Band Software-Defined Radio

NASA's Space Communications and Navigation Testbed was installed on an external truss of the International Space Station in 2012. The testbed contains several software-defined radios (SDRs), including the Jet Propulsion Laboratory (JPL) SDR, which underwent performance testing throughout 2013 with NASA's Tracking and Data Relay Satellite System (TDRSS). On-orbit testing of the JPL SDR was conducted at S-band with the Glenn Goddard TDRSS waveform and compared against an extensive dataset collected on the ground prior to launch. This paper will focus on the development of a waveform power estimator on the ground post-launch and discuss the performance challenges associated with operating the power estimator in space.

waveforms↗
NASA NTRS2012

Teleoperation of Robonaut Using Finger Tracking

With the advent of new finger tracking systems, the idea of a more expressive and intuitive user interface is being explored and implemented. One practical application for this new kind of interface is that of teleoperating a robot. For humanoid robots, a finger tracking interface is required due to the level of complexity in a human-like hand, where a joystick isn't accurate. Moreover, for some tasks, using one's own hands allows the user to communicate their intentions more effectively than other input. The purpose of this project was to develop a natural user interface for someone to teleoperate a robot that is elsewhere. Specifically, this was designed to control Robonaut on the international space station to do tasks too dangerous and/or too trivial for human astronauts. This interface was developed by integrating and modifying 3Gear's software, which includes a library of gestures and the ability to track hands. The end result is an interface in which the user can manipulate objects in real time in the user interface. then, the information is relayed to a simulator, the stand in for Robonaut, at a slight delay.

robotics↗
NASA NTRS1979

A preliminary assessment of small steam Rankine and Brayton point-focusing solar modules

A preliminary assessment of three conceptual point-focusing distributed solar modules is presented. The basic power conversion units consist of small Brayton or Rankine engines individually coupled to two-axis, tracking, point-focusing solar collectors. An array of such modules can be linked together, via electric transport, to form a small power station. Each module also can be utilized on a stand-alone basis, as an individual power source.

Roschke, E. J.↗
NASA NTRS1992

Precise Applications Of The Global Positioning System

Report represents overview of Global Positioning System (GPS). Emphasizes those aspects of theory, history, and status of GPS pertaining to potential utility for highly precise scientific measurements. Current and anticipated applications include measurements of crustal motions in seismically active regions of Earth, measurements of rate of rotation of Earth and orientation of poles, tracking of non-GPS spacecraft in orbit around Earth, surveying, measurements of radio-signal-propagation delays, determinations of coordinates of ground stations, and transfer of precise time signals worldwide.

Lichten, Stephen M.↗
NASA NTRS1993

Network command processing system overview

The Network Command Processing System (NCPS) developed for the National Aeronautics and Space Administration (NASA) Ground Network (GN) stations is a spacecraft command system utilizing a MULTIBUS I/68030 microprocessor. This system was developed and implemented at ground stations worldwide to provide a Project Operations Control Center (POCC) with command capability for support of spacecraft operations such as the LANDSAT, Shuttle, Tracking and Data Relay Satellite, and Nimbus-7. The NCPS consolidates multiple modulation schemes for supporting various manned/unmanned orbital platforms. The NCPS interacts with the POCC and a local operator to process configuration requests, generate modulated uplink sequences, and inform users of the ground command link status. This paper presents the system functional description, hardware description, and the software design.

Nam, Yon-Woo↗
NASA NTRS2000

Delta 2 Explosion Plume Analysis Report

A Delta II rocket exploded seconds after liftoff from Cape Canaveral Air Force Station (CCAFS) on 17 January 1997. The cloud produced by the explosion provided an opportunity to evaluate the models which are used to track potentially toxic dispersing plumes and clouds at CCAFS. The primary goal of this project was to conduct a case study of the dispersing cloud and the models used to predict the dispersion resulting from the explosion. The case study was conducted by comparing mesoscale and dispersion model results with available meteorological and plume observations. This study was funded by KSC under Applied Meteorology Unit (AMU) option hours. The models used in the study are part of the Eastern Range Dispersion Assessment System (ERDAS) and include the Regional Atmospheric Modeling System (RAMS), HYbrid Particle And Concentration Transport (HYPACT), and Rocket Exhaust Effluent Dispersion Model (REEDM). The primary observations used for explosion cloud verification of the study were from the National Weather Service's Weather Surveillance Radar 1988-Doppler (WSR-88D). Radar reflectivity measurements of the resulting cloud provided good estimates of the location and dimensions of the cloud over a four-hour period after the explosion. The results indicated that RAMS and HYPACT models performed reasonably well. Future upgrades to ERDAS are recommended.

Evans, Randolph J.↗
NASA NTRS2010

Low Earth Orbit Space Environment Testing of Extreme Temperature 6H-SiC JFETs on the International Space Station

This paper reports long-term electrical results from two 6H-SiC junction field effect transistors (JFETs) presently being tested in Low Earth Orbit (LEO) space environment on the outside of the International Space Station (ISS). The JFETs have demonstrated excellent functionality and stability through 4600 hours of LEO space deployment. Observed changes in measured device characteristics tracked changes in measured temperature, consistent with wellknown JFET temperature-dependent device physics.

Neudeck, Philip G.↗
NASA NTRS2016

High Bandwidth Optical Links for Micro-Satellite Support

A method, systems, apparatus and device enable high bandwidth satellite communications. An onboard tracking detector, installed in a low-earth orbit satellite, detects a position of an incoming optical beam received/transmitted from a first ground station of one or more ground stations. Tracker electronics determine orientation information of the incoming optical beam based on the position. Control electronics receive the orientation information from the tracker electronics, and control a waveguide drive electronics. The waveguide drive electronics control a voltage that is provided to an electro-optic waveguide beam steering device. The electro-optic waveguide beam steering device steers an outgoing optical beam to one of the one or more ground stations based on the voltage.

Chao, Tien-Hsin↗
NASA NTRS1974

Spaceflight tracking and data network operational reliability computer output for MTBF and availability. Appendix V to CSC-1-395

Tables of data are provided to show the availability of Skylab data to selected ground stations during the phases of Skylab preflight, Skylab unmanned condition, and Skylab manned condition. The mean time between failure (MTBF) of the same Skylab functions is tabulated for the selected ground stations. All reliability data are based on a 90 percent confidence interval.

Seneca, V. I.↗
NASA NTRS1996

Autonomous Navigation With Ground Station One-Way Forward-Link Doppler Data

The National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) has spent several years developing operational onboard navigation systems (ONS's) to provide real time autonomous, highly accurate navigation products for spacecraft using NASA's space and ground communication systems. The highly successful Tracking and Data Relay Satellite (TDRSS) ONS (TONS) experiment on the Explorer Platform/Extreme Ultraviolet (EP/EUV) spacecraft, launched on June 7, 1992, flight demonstrated the ONS for high accuracy navigation using TDRSS forward link communication services. In late 1994, a similar ONS experiment was performed using EP/EUV flight hardware (the ultrastable oscillator and Doppler extractor card in one of the TDRSS transponders) and ground system software to demonstrate the feasibility of using an ONS with ground station forward link communication services. This paper provides a detailed evaluation of ground station-based ONS performance of data collected over a 20 day period. The ground station ONS (GONS) experiment results are used to project the expected performance of an operational system. The GONS processes Doppler data derived from scheduled ground station forward link services using a sequential estimation algorithm enhanced by a sophisticated process noise model to provide onboard orbit and frequency determination. Analysis of the GONS experiment performance indicates that real time onboard position accuracies of better than 125 meters (1 sigma) are achievable with two or more 5-minute contacts per day for the EP/EUV 525 kilometer altitude, 28.5 degree inclination orbit. GONS accuracy is shown to be a function of the fidelity of the onboard propagation model, the frequency/geometry of the tracking contacts, and the quality of the tracking measurements. GONS provides a viable option for using autonomous navigation to reduce operational costs for upcoming spacecraft missions with moderate position accuracy requirements.

Horstkamp, G. M.↗
NASA NTRS1994

Software-Implemented Fault Tolerance in Communications Systems

Software-implemented fault tolerance (SIFT) is used in many computer-based command, control, and communications (C(3)) systems to provide the nearly continuous availability that they require. In the communications subsystem of Space Station Alpha, SIFT algorithms are used to detect and recover from failures in the data and command link between the Station and its ground support. The paper presents a review of these algorithms and discusses how such techniques can be applied to similar systems found in applications such as manufacturing control, military communications, and programmable devices such as pacemakers. With support from the Tracking and Communication Division of NASA's Johnson Space Center, researchers at the University of Wyoming are developing a testbed for evaluating the effectiveness of these algorithms prior to their deployment. This testbed will be capable of simulating a variety of C(3) system failures and recording the response of the Space Station SIFT algorithms to these failures. The design of this testbed and the applicability of the approach in other environments is described.

Gantenbein, Rex E.↗
NASA NTRS1986

Budget availability

A forecast of the total NASA budget required to achieve a manned mission to Mars at around the end of this century is described. A methodology is presented for projecting the major components of the NASA budget, including the NASA base, space flight, space station, Shuttle Derived Launch Vehicle, and the Manned Mars Mission. The NASA base, including administrative expenses, construction of facilities and research and development other than manned flight, is assumed to level off at the present (1985) level and remain constant at approximately $3.5 billion (constant fiscal year 1985 dollars). The budget for space flight, which consists of Shuttle research and development, operations, and tracking and data acquisition costs, is projected to decrease from approximately $4 billion in 1985 to just under $2.5 billion by 1989 and then level off. Planning profiles for three major programs are constructed: a permanently manned space station; a Shuttle Derived Vehicle; and a Manned Mars Mission. It is concluded that all of the programs can be conducted by the year 2002 with a 3 percent real growth rate in the NASA budget.

Cyr, Kelley J.↗
NASA NTRS1987

Space Network mission support in the Space Station era

The Mission Model for user support and NASA's plans to provide the necessary support resources are discussed. Particular attention is given to considerations which imply operation of up to two additional Tracking and Data Relay Satellites (TDRS), as well as potential interoperability with data relay satellite systems planned for launch in the mid-1990s by the ESA and by the NASDA of Japan. NASA activities related to the development of an Advanced TDRS system for the support of missions flying in the 21st century are also discussed.

Harris, David W.↗
NASA NTRS1958

Microlock- a minimum weight radio instrumentation system for a satellite

The design, construction and laboratory testing of a satellite tracking system are described. The tracking mechanism employs a low power, lightweight flight transmitter in conjunction with a receiving system of advanced design. The flight transmitter will radiate 3 mw for three months and will provide two narrow hand telemetering channels in a unit having a total weight of 2 lb. The ground receiving equipment is capable of acquiring and tracking the beacon signal at a line-of-sight distance of 3000 miles and at any azimuth and elevation angle. Interferometer antennas could he used to determine the angular position of the satellite with an accuracy of one milliradian, which is equivalent to approximately ±0.04 sec in the determination of the period.

Earth Satellites↗
NASA NTRS1974

Earth Observatory Satellite system definition study. Report no. 3: Design/cost tradeoff studies. Appendix E: EOS program supporting system trade data. Part 2: System trade studies no. 9 - 19

The relative merits of several international data acquisition (IDA) alternatives for the Earth Observatory Satellite (EOS) are established and rated on a cost effectiveness basis. The primary alternatives under consideration are: (1) direct transmission to foreign ground stations, (2) a wideband video tape recorder system for collection of foreign data and processing and distribution from the United States, and (3) a tracking and data relay satellite (TDRS) system for the relay of foreign data to the United States for processing and distribution. A requirements model is established for the analysis on the basis of the heaviest concentration of agricultural areas around the world. The model, the orbit path and the constraints of EOS and data volume summaries are presented. Alternative system descriptions and costs are given in addition to cost-performance summaries.

Source record↗
NASA NTRS1975

Viking

The Viking program, its characteristics, goals, and investigations are described. The program consists of launching two spacecraft to Mars in 1975 to soft-land on the surface and test for signs of life. Topics discussed include the launch, the journey through space, tracking, Mars orbit and landing, experiments on the search for life, imaging systems, lander camera, water detection experiments, thermal mapping, and a possible weather station on Mars.

Source record↗
NASA NTRS1981

A multiple access communication network based on adaptive arrays

A single frequency communication system is considered consisting of K possibly moving users distributed in space simultaneously communicating with a central station equipped with a computationally adapted array of n = or K antennas. Such a configuration could result if K spacecraft were to be simultaneously tracked by a single DSN complex consisting of an n antennas array. The array employs K sets of n weights to segregate the signals received from the K users. The weights are determined by direct computation based on known position information of the K users. Currently known techniques require (for n = K) about (4/3)K to the 4th power computer operations (multiply and add) to perform such computations. A technique that accomplishes this same goal in 8 K to the 3rd power operations, yielding a reduction by a factor K/6, was developed.

Zohar, S.↗
NASA NTRS1988

Block Oriented Simulation System (BOSS)

Computer simulation is assuming greater importance as a flexible and expedient approach to modeling system and subsystem behavior. Simulation has played a key role in the growth of complex, multiple access space communications such as those used by the space shuttle and the TRW-built Tracking and Data Relay Satellites (TDRS). A powerful new simulator for use in designing and modeling the communication system of NASA's planned Space Station is being developed. Progress to date on the Block (Diagram) Oriented Simulation System (BOSS) is described.

Ratcliffe, Jaimie↗