Search Results

14151–14200 of 16378 results (0.015 seconds)

Data Sets and Information
• instrument : Phoenix Lander Robotic Arm
  The Phoenix Lander Robotic Arm (RA) was a 2.4-m long arm mounted on the lander. It had three joints. The shoulder joint, where the RA was attached to the lander deck, had two degrees of freedom: motion in azimuth and elevation. The elbow and wrist joints each had one degree of freedom allowing further motions in elevation. Attached to the RA were: a scoop, a Thermal and Electrical Conductivity Probe (TECP), and the Robotic Arm Camera (RAC). The RA was designed to acquire samples of martian soil, dig trenches to uncover subsurface ice, modify the terrain close to the lander, and serve as a means to insert the TECP into the soil. The scoop had a drill bit on its back; after rasping icy soil, a series of RA motions was often used to send the material to the front of the scoop. Both the scoop and TECP were mounted on the wrist joint of the arm. Motor currents, link lengths, and joint positions of the RA were used to determine the force the RA exerted during its motions and the position of the scoop during these motions. This information was useful in monitoring the safety of the instrument and had the science return of allowing analysis of soil properties at the landing site.
• instrument : Phoenix Lander Robotic Arm Camera
  The Phoenix Lander Robotic Arm Camera (RAC) was a variable-focus color camera mounted to the Robotic Arm (RA). It was designed to acquire both close-up images of the Martian surface and microscopic images (down to a scale of 23 micron/px) of material collected in the RA scoop. The mounting position at the end of the robotic arm allowed the RAC to be actively positioned for imaging of targets not easily seen by the Stereo Surface Imager (SSI), such as excavated trench walls and targets under the lander structure. Color information was acquired by illuminating the target with red, green and blue light emitting diodes. Digital terrain models (DTM) were generated from RAC images acquired from different view points. This could, e.g., provide high-resolution stereo information about fine details of the trench walls.
• instrument : Phoenix Lander Surface Stereo Imager
  The Phoenix Lander Surface Stereo Imager (SSI) was a camera system designed to capture detailed images of the Martian surface. It took high-resolution color photos of the lander's surroundings, including the polar region's ice and soil. The SSI also provided key data for analyzing the terrain, weather patterns, and potential landing sites for future missions. Its images helped scientists understand Mars' geology and climate.
• instrument : Phoenix Lander Thermal and Evolved Gas Analyzer
  The Phoenix Lander Thermal and Evolved Gas Analyzer (TEGA) was composed of two separate components which were closely coupled: a Scanning Calorimeter (SC) and a mass spectrometer as an Evolved Gas Analyzer (EGA). TEGA had the capability of performing scanning calorimetry on eight small soil samples selected in the vicinity of the lander. The samples were heated in ovens to temperatures up to 1000C, and the volatile compounds (e.g., water and carbon dioxide), which were released during the heating, were analyzed in the EGA. The power required by the sample oven was continuously monitored during the heating, allowing analysis of both endothermic and exothermic phase transitions, which could be used to identify the phases present. By correlating the gas release with the calorimetry, the abundance and composition of the volatile compounds associated with the different phases could be determined. The EGA mass spectrometer was sensitive to detection levels down to 10 parts per billion, a level that might detect minute quantities of organic molecules potentially existing in the ice and soil.
• instrument : Phoenix Lander Telltale
  The Phoenix Lander Telltale wind indicator was a mechanical anemometer designed to operate on the Martian surface as part of the meteorological package on the NASA Phoenix lander. It consisted of a lightweight cylinder suspended by Kevlar fibers and was deflected under the action of wind. Imaging of the Telltale deflection with the Surface Stereo Imager (SSI) allowed the wind speed and direction to be quantified. Wind measurements were made with a frequency determined by how frequently the SSI could take images (down to once every 50 seconds).
• instrument : C-Tape Planetary Spectrophotometer Facility Analytical Spectral Devices LabSpec 4
  The Analytical Spectral Devices LabSpec 4 is located at the C-Tape Planetary Spectrophotometer Facility in Manitoba, Canada. It is an advanced, portable spectrometer designed for high-precision field spectroscopic measurements. It covers a wide spectral range of 350 to 2500 nm, spanning the visible, near-infrared (NIR), and shortwave infrared (SWIR) regions. The FieldSpec 4 is used in a variety of applications, including environmental monitoring, agriculture, mineralogy, and remote sensing, to analyze the composition of materials and surfaces. It features improved signal-to-noise ratios and enhanced data accuracy, making it suitable for demanding field environments.
• instrument : DLR Planetary Spectroscopy Laboratory Bruker VERTEX 80v
  The Bruker VERTEX 80v is located at the DLR Planetary Spectroscopy Laboratory in Berlin, Germany. It is a high-performance Fourier Transform Infrared (FTIR) spectrometer designed for advanced chemical analysis and material characterization. It offers exceptional spectral resolution, sensitivity, and accuracy, operating in a broad range from the far infrared to the mid-infrared (4000 to 50 cm⁻¹). The VERTEX 80v is used in research and industrial applications, including chemical and pharmaceutical analysis, environmental monitoring, and materials science. Its robust design and customizable configurations allow for both routine and cutting-edge analysis with high flexibility and precision.
• instrument : The Psyche Gamma Ray Spectrometer (GRS) aboard the Psyche spacecraft
  The Gamma Ray Spectrometer (GRS) will detect, measure, and map the asteroid (16) Psyche's elemental composition. The instrument is mounted on a 6-foot (2-meter) boom to distance the sensors from background radiation created by energetic particles interacting with the spacecraft and to provide an unobstructed field of view.
• instrument : Deep Space Climate Observatory Earth Polychromatic Imaging Camera
  EPIC (Earth Polychromatic Imaging Camera) is a 10-channel spectroradiometer (317 – 780 nm) onboard NOAA’s DSCOVR (Deep Space Climate Observatory) spacecraft. EPIC provides 10 narrow band spectral images of the entire sunlit face of Earth using a 2048x2048 pixel CCD (Charge Coupled Device) detector coupled to a 30-cm aperture Cassegrain telescope. The EPIC camera also captures images of solar eclipses and images of the Moon as it passes between DSCOVR and Earth.
• instrument : The Psyche Magnetometer (MAG) aboard the Psyche spacecraft
  The Psyche Magnetometer (MAG) is designed to detect and measure the remanent magnetic field of the asteroid (16) Psyche. It is composed of two identical high-sensitivity magnetic field sensors located at the middle and outer end of a 6-foot (2-meter) boom.
• instrument : The Psyche Neutron Spectrometer (NS) aboard the Psyche spacecraft
  The Neutron Spectrometer (NS) will detect, measure, and map the elemental composition of asteroid (16) Psyche. The instrument is mounted on a 6-foot (2-meter) boom to distance the sensors from background radiation created by energetic particles interacting with the spacecraft and to provide an unobstructed field of view.
• instrument : The Psyche Radio Science Subsystem (RSS) aboard the Psyche spacecraft
  The Psyche Radio Science Investigation uses the spacecraft’s X-band telecommunication system to measure the Doppler shift of the spacecraft. The mass of 16 Psyche imparts a deltav on the spacecraft. The concept of operations to support the Doppler-shift measurements entails measuring the Doppler signature of the spacecraft before and after the flyby to determine the change in velocity.
• instrument : Ion Mass Spectrometer for Pioneer Venus Probe Bus
  The Probe Bus Ion Mass Spectrometer (BIMS) of Pioneer Venus was an ion mass spectrometer experiment that obtained measurements to provide information on the solar wind interaction with Venus, upper atmosphere photochemistry, and the mass and heat transport characteristics of the atmosphere. A Bennett ion spectrometer, similar to units flown on many earth satellites and rockets, measured Venus' upper atmosphere ion concentrations in the mass range from 1 to 60 atomic mass units (u) from the time of crossing Venus' bowshock to bus burnup. The spectrometer consisted of an analyzer tube and electronics package, which contained low- and high-gain pre-amplifiers, amplifiers, a log A/D converted, and RF generator, voltage regulator, command and control, and data handling. The analyzer tube had the ability to produce simulated ion currents for calibration. BIMS operated with repeated explore/adapt cycles, each with a duration of 6.3 seconds.
• instrument : Neutral Mass Spectrometer for Pioneer Venus Probe Bus
  The Probe Bus Neutral Mass Spectrometer (BNMS) of Pioneer Venus was a neutral particle mass spectrometer experiment that obtained measurements to provide information on the origin and evolution of Venus' atmosphere, the present energy balance and dynamics of the upper atmosphere, and the interaction of the upper atmosphere with solar radiation and the interplanetary medium. A magnetic deflection, double-focusing mass spectrometer was flown to measure the upper atmosphere neutral molecules in the mass range 1 to 46 atomic mass units (u). Particles were ionized by an electron beam of 56-eV electrons at 100 microamps, and then first passed through focusing electrodes, followed by passage through an electrostatic analyzer and into the magnetic analyzer, which is a permanent magnet of Alnico 700 with a flux density of 0.5T. The data rate was fixed at 512 bits/sec, while measurements were obtained from about 700 km altitude to 130 km, at which point the probe stopped operating.
• instrument : Differential Long Base Line Interferometer for PIONEER VENUS LARGE PROBE
  This experiment involved applying differential long-baseline interferometry techniques to the radio signals from the entry probes and bus in order to infer or place upper limits on wind speeds in the lower atmosphere. These results were used in modeling the circulation patterns of Venus' atmosphere. As the four probes descended, the Pioneer Venus Probe Bus followed a well-defined ballistic trajectory above the atmosphere that was accurately known with respect to the planet's surface. Probe velocities were measured relative to the Bus. Additionally, four ground stations on Earth simultaneously tracked the four probes. These were the 64-meter dish Goldstone and Canberra Deep Space Network (DSN) stations, and the 9-meter dish Santiago (Chile) and Guam Spaceflight Tracking And Data Network (STDN) stations. They covered passbands of 2291 to 2293 MHz to receive signals from all four probes and the bus simultaneously. The Doppler frequency shifts of the received 13 cm (S-band) signals gave the component of the velocity vector along the Earth-spacecraft line of sight. The differential long-baseline interferometry was used to find the other two components of the velocity vector of each probe. Measurements of the temperature and pressure taken by other instruments as the probes descended were used with the interferometry results. Data taken prior to probe entry were used, where feasible, to infer characteristics of Venus' gravity field for use with probe entry operations as well as in later scientific evaluation. Deviations of the probe trajectories from the mathematical model of their trajectories in a still atmosphere were attributed to winds. Overall uncertainties were estimated at 10 cm/s. The magnitude of the wind velocity was found to be about 1 meter/s or less near the surface of the planet and about 100 meters/s near 65-km altitude at all four probe locations. High wind shear was measured centered at altitudes of 15, 45, and 60 km. The wind velocity was uniformly directed very close to due west, except within a few km of the surface.
• instrument : Atmospheric Structure Experiment for Pioneer Venus Large Probe
  The Large Probe Atmospheric Structure Experiment (LAS) of Pioneer Venus had instruments that included a three-axis accelerometer, pressure sensors, and temperature sensors. They were based on the technology demonstrated by the PAET rocket vehicle (Planetary Atmosphere Experiment Test R7106-2001). The measurements were used to construct a profile of atmosphere state properties for the large probe trajectory from the surface to approximately 140 km altitude. They were also used to determine vertical wind velocity, horizontal wind velocity, and turbulence. By comparing atmospheric conditions along the large probe trajectory with those measured by the small probes, circulation models of the atmosphere were determined. The instruments weighed about 2.3 kg and consumed about 4.9 W of power.
• instrument : Cloud Particle Size Spectrometer for Pioneer Venus Large Probe
  The Large Probe Cloud Particle Size Spectrometer (LCPS) of Pioneer Venus was an instrument with the objective to measure Venus' cloud particle sizes and concentrations. The LCPS comprised of a laser, spectrometers, a sapphire window, a system of prisms and lenses, array detectors, and electronics. The 2 mW He-Ne ruggedized Coherent 80-2T laser was used to illuminate cloud particles. The spectrometers are an Optical Array Spectrometer (OAS) that covers 5 to 500 microns particle range, and a Scattering Subrange Spectrometer (SSR), which covers a particle size range from 0.5 to 5 microns. Optical lenses imaged the particle shadows on arrays of detectors. The particle shadows were used to determine particle size and concentration. For low-rate channels, output data were registered to an 8-bit counter, while for high-rate channels it was a log compressed counter. The flight sensor was similar to those flown in aircraft and balloons.
• instrument : Gas Chromatograph for Pioneer Venus Large Probe
  The Large Probe Gas Chromatograph (LGC) of Pioneer Venus was an instrument with the objective to determine the composition of Venus' lower atmosphere. From these measurements, deductions were made of the gaseous sources of infrared opacity, the degree of differentiation of Venus' interior, the degree of similarity between the solid bodies of earth and Venus, and evolution of Venus' atmosphere. Gases the LGC was designed to detect and measure included oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2), nitrogen (N2), water vapor (H2O), and sulfur dioxide (SO2). Two gas chromatograph columns were used to analyze samples of the atmosphere during probe descent. The long column, which was used for gases with mass range from neon to carbon dioxide, was kept at a temperature of 18.3 degrees C, and was made up of two 1585 cm long packed bifilarly wound columns, with 1.1 mm internal diameter. The short column, used for gases with masses between carbon dioxide and sulfur dioxide, was made up of two 213 cm long bifilarly wound columns (as well as an internal diameter of 1.1 mm), and operated at a temperature of 62.0 degrees C.
• instrument : Infrared Radiometer for Pioneer Venus Large Probe
  The Large Probe Infrared Radiometer (LIR) of Pioneer Venus was used to measure the atmosphere thermal flux profile, detect cloud layers and infer their composition, and estimate the atmospheric water vapor content. The instrument, comprised of a six-channel calibrated radiometer, measured the radiance difference at plus/minus 45 degrees to the horizontal. It operated in the wavelength range from 3 to 50 microns. Two internal blackbodies were used to allow absolute measurements of the flux in each channel. The instrument weighed about 2 kg and used about 3 W of power.
• instrument : Nephelometer for Pioneer Venus Large Probe
  The Large Probe Nephelometer (LN) of Pioneer Venus was an instrument that measured the energy backscattered from cloud particles, at around a wavelength of 900 nm. It used a solid-state pulsed gallium arsenide laser light emitting diode (LED) and detectors to illuminate the clouds. These detectors were made of three solid state photodiodes to allow the detection of the backscattering, ultraviolet background, and visible background. The altitude history of the backscattered signal indicated the presence and vertical extent of clouds along the trajectory. Comparisons with the measurements from the small probes indicated the spatial variability of the cloud structure. The experiment weighed about 0.5 kg and used about 1.3 W of power.
• instrument : Neutral Mass Spectrometer for Pioneer Venus Large Probe
  The Large Probe Neutral Mass Spectrometer (LNMS) of Pioneer Venus has a mass of 10.9 kg, a volume of 10650 cubic cm, and uses 14 W power. The instrument comprises a miniature magnetic sector-field mass analyzer, a gas inlet and pumping system, and an electronics (microprocessor) package all mounted on a 31 x 36 cm baseplate. It also had a noble gas enrichment cell, the Isotope Ratio Measurement Cell (IRMC), which collected an atmospheric sample at the beginning of instrument operation at around 62 km altitude. This sample was purged of carbon dioxide using sorption and getter pumping during the descent to enrich the inert gases in the cell, and then introduced the into the mass spectrometer just before parachute jettison. The inlet system consisted of a primary microleak (conductance of 0.0001 cubic mm per second) and a secondary microleak (0.001 cubic mm per second), which was only used in the upper atmosphere where the pressure was lower. The single focusing magnetic sector-field mass spectrometer consisted of the electron bombardment ion source, with selectable electron energies of 70 eV, 30 eV, or 22 eV, a magnetic momentum analyzer and a detector system, which had two electron multiplier-counter channels, one covering 1 - 16 amu and the other covering 15 - 208 amu. It also had two calibration gases containing 136Xe+, 136Xe++, and CH3+ producing peaks at 135.907, 67.954, and 15.035 amu.
• instrument : Solar Flux Radiometer for Pioneer Venus Large Probe
  The Large Probe Solar Flux Radiometer (LSFR) of Pioneer Venus was used to determine the regions in Venus' atmosphere where solar energy is deposited. To measure the intensity of scattered solar light, narrow-field-of-view detectors were used, covering the spectral range from 0.4 to 1.8 microns. As the probe descended through the atmosphere, the LSFR continuously measured the difference in atmospheric radiance above and below the horizon of the probe as a function of altitude, which allows the determination of how much sunlight was absorbed by the clouds and how much reached the surface. This approach provides more accurate radiation balance modeling of the atmosphere and will provide information on the role of the greenhouse effect on the heating of the Venus atmosphere. The instrument consisted of five 3-mm diameter fused silica lenses, with focal length of 11.45 mm and focal ratio of F/3.8, pointing in different directions: zenith (27 degrees), nadir (142 degrees), and 3 lenses at roughly azimuthally (60, 83, and 102 degrees).
• instrument : Differential Long Base Line Interferometer for PIONEER VENUS SMALL PROBE (DAY)
  This experiment involved applying differential long-baseline interferometry techniques to the radio signals from the entry probes and bus in order to infer or place upper limits on wind speeds in the lower atmosphere. These results were used in modeling the circulation patterns of Venus' atmosphere. As the four probes descended, the Pioneer Venus Probe Bus followed a well-defined ballistic trajectory above the atmosphere that was accurately known with respect to the planet's surface. Probe velocities were measured relative to the Bus. Additionally, four ground stations on Earth simultaneously tracked the four probes. These were the 64-meter dish Goldstone and Canberra Deep Space Network (DSN) stations, and the 9-meter dish Santiago (Chile) and Guam Spaceflight Tracking And Data Network (STDN) stations. They covered passbands of 2291 to 2293 MHz to receive signals from all four probes and the bus simultaneously. The Doppler frequency shifts of the received 13 cm (S-band) signals gave the component of the velocity vector along the Earth-spacecraft line of sight. The differential long-baseline interferometry was used to find the other two components of the velocity vector of each probe. Measurements of the temperature and pressure taken by other instruments as the probes descended were used with the interferometry results. Data taken prior to probe entry were used, where feasible, to infer characteristics of Venus' gravity field for use with probe entry operations as well as in later scientific evaluation. Deviations of the probe trajectories from the mathematical model of their trajectories in a still atmosphere were attributed to winds. Overall uncertainties were estimated at 10 cm/s. The magnitude of the wind velocity was found to be about 1 meter/s or less near the surface of the planet and about 100 meters/s near 65-km altitude at all four probe locations. High wind shear was measured centered at altitudes of 15, 45, and 60 km. The wind velocity was uniformly directed very close to due west, except within a few km of the surface.
• instrument : Atmosphere Structure Experiment for Pioneer Venus Small Probe (Day)
  The Small Probe (Day) Atmosphere Structure Experiment (SAS) of Pioneer Venus included a single-axis accelerometer, pressure sensors, and temperature sensors. They were based on the technology demonstrated by the PAET rocket vehicle (Planetary Atmosphere Experiment Test R 7106-2001). The measurements were used to construct a profile of atmospheric state properties for the trajectory from the surface to approximately 140 km altitude. They were also used to determine vertical wind velocity, horizontal wind velocity, and turbulence. By comparing atmospheric conditions along this trajectory with those measured by the other Probes, circulation models of the atmosphere were determined. The instruments weighed about 1.2 kg and consumed about 4.8 W of power.
• instrument : Nephelometer for Pioneer Venus Small Probe (Day)
  The Small Probe (Day) Nephelometer (SN) of Pioneer Venus was an instrument with the objectives to measure the energy backscattered from cloud particles, at around a wavelength of 900 nm. To illuminate the clouds, it used a solid-state pulsed gallium arsenide laser light emitting diode (LED) and detectors. These detectors were made of three solid state photodiodes to allow the detection of the backscattering, ultraviolet background, and visible background. The altitude history of the backscattered signal indicated the presence and vertical extent of clouds along the trajectory. When comparing the measurements from other probes, indications of the spatial variability of the cloud structure were found. The experiment weighed about 0.6 kg and used about 1.3 W of power.
• instrument : Net Flux Radiometer for Pioneer Venus Small Probe (Day)
  The Small Probe (Day) Net Flux Radiometer (SNFR) of Pioneer Venus was an instrument with the objectives to locate regions of radiative convergence and divergence as a function of altitude and to indicate the height at which solar energy is absorbed by the atmosphere of Venus, measured within the spectral range of 0.2 to 50 microns with a resolution of 1km. This experiment used a small net flux radiometer on the Probe targeted to the dayside of Venus to measure the net solar flux in the 0.2 to 4 micron region. The two probes targeted to the nightside of the planet carried net infrared flux sensors covering the 1 to 25 micron region. The SNFR was made of two modules, with the electronics module comprised of five circuit boards inside a gold plated titanium box. The modules contained amplifier, voltage controlled oscillator, max/min electronics, digital electronics, heater and solenoid drivers, power conversion unit, and temperature monitors. Two measurement periods were used by SNFR. When the probe’s altitude was roughly above 30 km, it used 8 second measurements, while below this altitude, it obtained maximum, minimum, and average flux difference measurements.
• instrument : Differential Long Base Line Interferometer for PIONEER VENUS SMALL PROBE (NIGHT)
  This experiment involved applying differential long-baseline interferometry techniques to the radio signals from the entry probes and bus in order to infer or place upper limits on wind speeds in the lower atmosphere. These results were used in modeling the circulation patterns of Venus' atmosphere. As the four probes descended, the Pioneer Venus Probe Bus followed a well-defined ballistic trajectory above the atmosphere that was accurately known with respect to the planet's surface. Probe velocities were measured relative to the Bus. Additionally, four ground stations on Earth simultaneously tracked the four probes. These were the 64-meter dish Goldstone and Canberra Deep Space Network (DSN) stations, and the 9-meter dish Santiago (Chile) and Guam Spaceflight Tracking And Data Network (STDN) stations. They covered passbands of 2291 to 2293 MHz to receive signals from all four probes and the bus simultaneously. The Doppler frequency shifts of the received 13 cm (S-band) signals gave the component of the velocity vector along the Earth-spacecraft line of sight. The differential long-baseline interferometry was used to find the other two components of the velocity vector of each probe. Measurements of the temperature and pressure taken by other instruments as the probes descended were used with the interferometry results. Data taken prior to probe entry were used, where feasible, to infer characteristics of Venus' gravity field for use with probe entry operations as well as in later scientific evaluation. Deviations of the probe trajectories from the mathematical model of their trajectories in a still atmosphere were attributed to winds. Overall uncertainties were estimated at 10 cm/s. The magnitude of the wind velocity was found to be about 1 meter/s or less near the surface of the planet and about 100 meters/s near 65-km altitude at all four probe locations. High wind shear was measured centered at altitudes of 15, 45, and 60 km. The wind velocity was uniformly directed very close to due west, except within a few km of the surface.
• instrument : Atmosphere Structure Experiment for Pioneer Venus Small Probe (Night)
  The Small Probe (Night) Atmosphere Structure Experiment (SAS) of Pioneer Venus included a single-axis accelerometer, pressure sensors, and temperature sensors. They were based on the technology demonstrated by the PAET rocket vehicle (Planetary Atmosphere Experiment Test R 7106-2001). The measurements were used to construct a profile of atmospheric state properties for the trajectory from the surface to approximately 140 km altitude. They were also used to determine vertical wind velocity, horizontal wind velocity, and turbulence. By comparing atmospheric conditions along this trajectory with those measured by the other Probes, circulation models of the atmosphere were determined. The instruments weighed about 1.2 kg and consumed about 4.8 W of power.
• instrument : Nephelometer for Pioneer Venus Small Probe (Night)
  The Small Probe (Night) Nephelometer (SN) of Pioneer Venus was an instrument with the objectives to measure the energy backscattered from cloud particles, at around a wavelength of 900 nm. To illuminate the clouds, it used a solid-state pulsed gallium arsenide laser light emitting diode (LED) and detectors. These detectors were made of three solid state photodiodes to allow the detection of the backscattering, ultraviolet background, and visible background. The altitude history of the backscattered signal indicated the presence and vertical extent of clouds along the trajectory. When comparing the measurements from other probes, indications of the spatial variability of the cloud structure were found. The experiment weighed about 0.6 kg and used about 1.3 W of power.
• instrument : Net Flux Radiometer for Pioneer Venus Small Probe (Night)
  The Small Probe (Night) Net Flux Radiometer (SNFR) of Pioneer Venus was an instrument with the objectives to locate regions of radiative convergence and divergence as a function of altitude and to indicate the height at which solar energy is absorbed by the atmosphere of Venus, measured within the spectral range of 0.2 to 50 microns with a resolution of 1km. This experiment used a small net flux radiometer on the Probe targeted to the dayside of Venus to measure the net solar flux in the 0.2 to 4 micron region. The two probes targeted to the nightside of the planet carried net infrared flux sensors covering the 1 to 25 micron region. The SNFR was made of two modules, with the electronics module comprised of five circuit boards inside a gold plated titanium box. The modules contained amplifier, voltage controlled oscillator, max/min electronics, digital electronics, heater and solenoid drivers, power conversion unit, and temperature monitors. Two measurement periods were used by SNFR. When the probe’s altitude was roughly above 30 km, it used 8 second measurements, while below this altitude, it obtained maximum, minimum, and average flux difference measurements. The instrument weighed about 0.4 kg and used 2.2 W of power.
• instrument : Differential Long Base Line Interferometer for PIONEER VENUS SMALL PROBE (NORTH)
  This experiment involved applying differential long-baseline interferometry techniques to the radio signals from the entry probes and bus in order to infer or place upper limits on wind speeds in the lower atmosphere. These results were used in modeling the circulation patterns of Venus' atmosphere. As the four probes descended, the Pioneer Venus Probe Bus followed a well-defined ballistic trajectory above the atmosphere that was accurately known with respect to the planet's surface. Probe velocities were measured relative to the Bus. Additionally, four ground stations on Earth simultaneously tracked the four probes. These were the 64-meter dish Goldstone and Canberra Deep Space Network (DSN) stations, and the 9-meter dish Santiago (Chile) and Guam Spaceflight Tracking And Data Network (STDN) stations. They covered passbands of 2291 to 2293 MHz to receive signals from all four probes and the bus simultaneously. The Doppler frequency shifts of the received 13 cm (S-band) signals gave the component of the velocity vector along the Earth-spacecraft line of sight. The differential long-baseline interferometry was used to find the other two components of the velocity vector of each probe. Measurements of the temperature and pressure taken by other instruments as the probes descended were used with the interferometry results. Data taken prior to probe entry were used, where feasible, to infer characteristics of Venus' gravity field for use with probe entry operations as well as in later scientific evaluation. Deviations of the probe trajectories from the mathematical model of their trajectories in a still atmosphere were attributed to winds. Overall uncertainties were estimated at 10 cm/s. The magnitude of the wind velocity was found to be about 1 meter/s or less near the surface of the planet and about 100 meters/s near 65-km altitude at all four probe locations. High wind shear was measured centered at altitudes of 15, 45, and 60 km. The wind velocity was uniformly directed very close to due west, except within a few km of the surface.
• instrument : Atmosphere Structure Experiment for Pioneer Venus Small Probe (North)
  The Small Probe (North) Atmosphere Structure Experiment (SAS) of Pioneer Venus included a single-axis accelerometer, pressure sensors, and temperature sensors. They were based on the technology demonstrated by the PAET rocket vehicle (Planetary Atmosphere Experiment Test R 7106-2001). The measurements were used to construct a profile of atmospheric state properties for the trajectory from the surface to approximately 140 km altitude. They were also used to determine vertical wind velocity, horizontal wind velocity, and turbulence. By comparing atmospheric conditions along this trajectory with those measured by the other Probes, circulation models of the atmosphere were determined. The instruments weighed about 1.2 kg and consumed about 4.8 W of power.
• instrument : Nephelometer for Pioneer Venus Small Probe (North)
  The Small Probe (North) Nephelometer (SN) of Pioneer Venus was an instrument with the objectives to measure the energy backscattered from cloud particles, at around a wavelength of 900 nm. To illuminate the clouds, it used a solid-state pulsed gallium arsenide laser light emitting diode (LED) and detectors. These detectors were made of three solid state photodiodes to allow the detection of the backscattering, ultraviolet background, and visible background. The altitude history of the backscattered signal indicated the presence and vertical extent of clouds along the trajectory. When comparing the measurements from other probes, indications of the spatial variability of the cloud structure were found. The experiment weighed about 0.6 kg and used about 1.3 W of power.
• instrument : Net Flux Radiometer for Pioneer Venus Small Probe (North)
  The Small Probe (North) Net Flux Radiometer (SNFR) of Pioneer Venus was an instrument with the objectives to locate regions of radiative convergence and divergence as a function of altitude and to indicate the height at which solar energy is absorbed by the atmosphere of Venus, measured within the spectral range of 0.2 to 50 microns with a resolution of 1km. This experiment used a small net flux radiometer on the Probe targeted to the dayside of Venus to measure the net solar flux in the 0.2 to 4 micron region. The two probes targeted to the nightside of the planet carried net infrared flux sensors covering the 1 to 25 micron region. The SNFR was made of two modules, with the electronics module comprised of five circuit boards inside a gold plated titanium box. The modules contained amplifier, voltage controlled oscillator, max/min electronics, digital electronics, heater and solenoid drivers, power conversion unit, and temperature monitors. Two measurement periods were used by SNFR. When the probe’s altitude was roughly above 30 km, it used 8 second measurements, while below this altitude, it obtained maximum, minimum, and average flux difference measurements. The instrument weighed about 0.4 kg and used 2.2 W of power.
• instrument : Orbiter Atmospheric Drag (OAD) for Pioneer Venus
  The Orbiter Atmospheric Drag (OAD) experiment utilized S-band and X-band radio signals from a spacecraft to gather data on the Venusian atmosphere. Its objectives included measuring the diurnal variation of thermospheric density, understanding the impact of solar wind on atmospheric density, examining the effects of solar extreme UV radiation, and investigating phenomena like semi-annual variations and super-rotation. The experiment analyzed Doppler shifts in radio transmissions to calculate spacecraft acceleration and drag coefficients, which, when combined with atmospheric models, helped estimate atmospheric density. The changing periapsis altitude allowed for sampling different atmospheric depths, contributing to studies on atmospheric variations and dynamics.
• instrument : Pioneer Venus Cloud Photopolarimeter
  The Cloud Photopolarimeter (OCPP) used a simplified version of the Imaging Photopolarimeter (IPP) flown on Pioneers 10 and 11 to provide low-resolution, four-color maps of the Venusian cloud cover with a high-resolution imaging capability near apocenter. The principal objective of this investigation was to determine the properties of the clouds and haze (both vertical and horizontal particle distribution), cloud particle size and refractive index, the cloud-top height, and the number density of particles. The instrument consists of a 3.7 cm Cassegrain telescope with a 15.7 cm focal length, backed by a 16 position filter wheel. The imaging mode has a 365-nm filter, a 0.4 x 0.45 mrad aperture field of view, and a single detector that feeds into the imaging channel. It can provide scan lines containing 1016 8-bit measurements of intensity (radiance), with a resolution of 30 km at the subspacecraft point. Approximately 3.5 hours are required to image the full planetary disk, or five full images in the roughly 18 hours of the orbit centered on apoapsis. The channel is sampled every 0.488 ms (0.610 ms low sample rate), absolute radiometric accuracy is 5%. The photopolarimetry mode uses four passband filters centered at 270 nm (far ultraviolet), 365 nm (ultraviolet), 550 nm (visible), and 935 nm (near infrared), with three half-wave retarder positions on the filter wheel for each of these. The field of view is 6.5 x 8 mrad, giving a resolution of 250 - 500 km at the subsatellite point. A Wollaston prism splits the output into two detectors, which are sampled simultaneously every 9.52 ms (28.6 ms low sample rate), with 11 bit a/d conversion, and an absolute radiometric accuracy of 5%. The limb-scan mode, used at the orbiter’s periapsis, uses a 690 nm filter with a 0.3 x 0.35 mrad field of view aperture and a single detector that feeds into the limb-scan channel, with a sampling every 0.310 ms (0.397 ms low sample rate) with 8 bit conversion, absolute radiometric accuracy is 5%. There is a calibration lamp for periodic calibration checks, which can view 0 to 145 degrees from the spacecraft spin axis by using the 5 rpm spin of the spacecraft. It uses a first in/first out 8192 bit memory (3072 bit section for photopolarimetry mode). The data format is 56 bits of status information followed by 8136 bits of data.
• instrument : Electric Field Detector (OEFD) for Pioneer Venus
  The Electric Field Detector (OEFD) for Pioneer Venus plasma wave instrument is a modified version of the Pioneer 8 and 9 experiments, designed to measure VLF electric fields at Venus across four narrow-band channels centered at 100, 730, 7350, and 30,000 Hz. Its goal is to analyze electric field interactions between the solar wind and Venus's plasma, as well as investigate plasma instabilities affecting heat flux and ion behavior. The instrument features a self-contained balanced V-type antenna and a 4-channel spectrum analyzer, with a total mass of 0.55 kg, and is capable of conducting spectral scans based on varying telemetry rates. The report outlines its design and in-flight performance.
• instrument : Electron Temperature Probe (OETP) for Pioneer Venus
  The Pioneer Venus Orbiter Electron Temperature Probe (OETP) is an instrument designed for in-situ measurements of electron temperature and plasma density in Venus' ionosphere. Utilizing cylindrical Langmuir probes, the OETP features adaptive voltage circuitry that continuously adjusts to changing conditions, enabling the collection of high-resolution data despite limited telemetry rates. The system includes independent amplifiers for each probe, adaptive sweep voltage circuits, and onboard data storage, facilitating the transmission of key ionospheric parameters to Earth. The probe has completed over 250 successful passes through Venus' nightside ionosphere, demonstrating robust performance in capturing crucial plasma characteristics.
• instrument : Gamma Ray Burst Detector (OGBD) for Pioneer Venus
  The Gamma Ray Burst Detector (OGBD) was an omnidirectional gamma-ray detector designed to observe high-energy gamma-ray bursts from astronomical sources, operating from 1978 to 1992. It utilized two Phoswich scintillation spectrometers sensitive to photon energies ranging from 0.1 to 2.0 MeV, enabling rapid data collection upon detecting gamma events. The instrument featured a full sky field of view and was capable of achieving source location accuracy of under one arc minute by leveraging long-distance data from Earth to Venus. With a total mass of 2.8 kg and power consumption of 1.3 W, the OGBD included multiple energy channels and utilized a pretrigger memory to capture transient data. Its data was compared with other satellite experiments for valid event confirmation.
• instrument : Ion Mass Spectrometer (OIMS) for Pioneer Venus
  The Pioneer Venus Orbiter Ion Mass Spectrometer (OIMS) was used to analyze the composition and concentration of thermal positive ions in Venus's ionosphere. This data helped interpret solar wind interactions with Venus, upper atmosphere photochemistry, and atmospheric mass and heat transport. The OIMS, designed similarly to instruments on previous missions, operates within a mass range of 1-56 amu and utilizes a Bennett radio-frequency mass spectrometer. Comprising an analyzer tube and an electronics package, the instrument weighs 3.0 kg and functions using 1.5 W of power for data processing and telemetry. The analyzer tube includes tungsten mesh grids and can measure 16 common ion masses. The instrument operates in 6.3-second cycles, alternating between an explore phase (measuring the selected masses) and an adapt phase (repeated measurements of detected ions).
• instrument : Infrared Radiometer (OIR) for Pioneer Venus
  The Orbiter Infrared Radiometer (OIR) was an advanced instrument designed for vertical temperature sounding of the atmosphere from cloud tops to 150 km on Venus, as well as for cloud morphology studies, including water vapor mapping. Based on Nimbus satellite technologies, the OIR operated for only 72 orbits before failing on February 14, 1979. The instrument featured eight channels, each focused on different wavelengths, which helped measure temperatures, cloud structures, total solar reflected intensity, and water vapor distribution. The OIR had dimensions of 24.8 x 17.5 x 25.1 cm, weighed 5.9 kg, and consumed 5.2 W of power, achieving a temperature sensitivity of better than 0.5 K. During its operation, it collected around 800,000 temperature profiles of the upper atmosphere.
• instrument : Fluxgate Magnetometer (OMAG) for Pioneer Venus
  The Fluxgate Magnetometer (OMAG) for Pioneer Venus operates with two ring-core sensors at the end of a 4.7-meter magnetometer boom and an additional sensor oriented at 45 degrees, is built upon the successful engineering principles utilized in previous Apollo missions. The primary objectives are to elucidate the presence of planetary and remnant magnetic fields, investigate the configuration and intensity of the ionospheric current system, analyze the energy and mass distribution in Venus's upper atmosphere, and explore solar wind interactions. Additionally, the instrument aims to characterize the Venusian near-wake region and the structure of the bow shock, as well as to assess the solar wind perturbations in the vicinity of Venus at different astronomical units (AU). The magnetometer architecture integrates three units: an electronics unit, an inboard sensor assembly, and an outboard sensor assembly, achieving a total mass of 2 kg with advanced operational capabilities. The magnetometers leverage a feedback-controlled triaxial fluxgate mechanism, enabling measurement resolution down to 1/16 gamma and accommodating varying sampling rates—critical during different mission phases. This research yields essential data, contributing to the fundamental understanding of Venus's space environment and the broader dynamics of solar system interactions, culminating in significant findings up to the last full orbital data collection on October 16, 1988.
• instrument : Orbiter Neutral Mass Spectrometer (ONMS) for Pioneer Venus
  The Neutral Mass Spectrometer (ONMS) is designed to measure the concentration of neutral atoms and molecules in Venus's upper atmosphere, ranging from 150 km to 500 km in altitude. The instrument is housed in a compact tube and includes a cylindrical chamber for ion source operations. It employs a quadrupole mass spectrometer with multiple ion-source modes to measure both noble gases in open mode and chemically active gases in closed mode, as well as a "flip-flop" mode for alternate measurements. The instrument can accurately analyze gas particles based on their mass, with a resolution of 0.0001 for mass readings from 1 to 46 amu. After being activated, the ONMS successfully detected and measured density variations of key atmospheric constituents including helium, oxygen, carbon dioxide, and nitrogen, contributing to a better understanding of Venus's atmospheric dynamics, chemistry, and thermal state.
• instrument : Solar Wind Plasma Analyzer (OPA) for Pioneer Venus
  The Solar Wind Plasma Analyzer (OPA) is a quadrispherical electrostatic analyzer designed to measure solar wind conditions such as velocity, density, flow direction, and temperature in various locations around Venus. It weighs 3.9 kg and operates on 5 W of power. The instrument features a pair of spherical plates with an entrance aperture that allows charged particles to pass through, eventually striking one of five current collectors. It can vary the voltage between the plates from 50 V to 8000 V for ions and from 3 V to 250 V for electrons, covering an extensive energy/charge range. It has a detection capability of particle flux in a 360-degree azimuth range and +/-85 degrees in elevation. The OPA operates in two modes: a command able scan mode to identify peak particle fluxes and a step mode for specific flux measurements.
• instrument : Surface Radar Mapper (ORAD) for Pioneer Venus
  The Pioneer Venus Orbiter's radar altimeter (ORAD) was designed to gather data on Venus's altitude, surface temperature, and radar properties to infer its topography and geological characteristics. Operating with a 38 cm antenna, ORAD emitted low-power S-band pulses to measure surface heights with an accuracy of 150 meters and derived data on electrical conductivity and surface roughness. The instrument weighed 9.7 kg and required 18 W of power, functioning when the spacecraft was below 4700 km altitude. ORAD conducted various measurements during each 12-second rotation of the spacecraft, including multiple altimetry measurements, radiometric assessments, and calibrations, aiming for high signal-to-noise ratios. The data collected ranged from December 5, 1978, to March 23, 1981, allowing detailed profiling of the Venusian surface.
• instrument : Orbiter Retarding Potential Analyzer (ORPA) for Pioneer Venus
  The Retarding Potential Analyzer (ORPA) is a Langmuir-probe retarding-potential analyzer designed to measure various characteristics of the ionosphere, including electron concentration, temperature, major ion concentrations, and ion drift velocities. An adaptation from an instrument flown on the German Aeros satellite in 1972, it has two sensor heads and operates in electron, ion, or photoelectron modes. The investigation aims to enhance understanding of ionic reactions in the Venusian ionosphere, plasma transport processes, and the interaction between the ionosphere and solar wind.The ORPA weighs 2.8 kg and operates on 2.4 W of power. It features an offset axis for alignment with the spacecraft's velocity vector and utilizes multiple collector grids to selectively funnel ionospheric particles. It operates in three modes: Langmuir probe, ion, and photoelectron, with varying voltage settings for different measurements. Scans are performed every 12 seconds while the spacecraft is in the ionosphere, allowing for numerous measurements and sampling data on concentrations, temperatures, and drift velocities of ions and electrons at specified intervals. A specific operational mode can measure total ion concentration over a 1-meter sampling distance along the spacecraft's trajectory.
• instrument : Pioneer Venus Orbiter Radio Science Experiment
  The Pioneer Venus Orbiter Radio Science Experiment was designed to use the spacecraft’s radio signal to study Venus’s atmosphere, ionosphere, gravity field, and surface properties. By analyzing changes in the frequency and phase of the spacecraft’s radio waves as they passed through the Venusian atmosphere, scientists could infer temperature, pressure, and density profiles. The experiment also provided data on the planet’s gravitational field by measuring tiny shifts in the spacecraft’s trajectory, helping to improve models of Venus’s internal structure. Additionally, the radio signals were used to study the solar corona when the spacecraft was in line with the Sun.
• instrument : Turbulence Experiment for Pioneer Venus Orbiter
  The Pioneer Venus Orbiter Turbulence Experiment (OTUR) used S- and X-band radio signals to measure turbulence intensity variations with altitude; planetary latitude and longitude; and atmospheric scale size distribution. It was designed to observe turbulence of scale sizes smaller than 10 km in the Venus atmosphere above 34 km for studying global patterns, and to measure ionospheric electron density variations.
• instrument : Pioneer Venus Orbiter Ultraviolet Spectrometer
  The Orbiter Ultraviolet Spectrometer (OUVS), or Airglow Ultraviolet Spectrometer, on Pioneer Venus was designed to map and make spectroscopic analyses of ultraviolet light scattered and emitted by the clouds and gases in the Venus atmosphere, in order to detect and measure airglow, scattered sunlight, and hydrogen Lyman-alpha emissions in the thermosphere, mesosphere, and exosphere of Venus. These measurements are used to establish and map the composition, temperature, and photochemistry of the thermosphere and ionosphere, to determine the pressure at and above the visible cloud tops, and to establish the distribution and escape rate of atomic hydrogen. The OUVS used a 250 mm Cassegrain telescope on a 125 mm focal length Ebert-Fastie monochromator with a programmable grating drive. The instrument operated in the 1100-3400 A region. The telescope had a lightshade assembly and a 5 cm aperture. It had a 1.83 x 0.16 degree field of view, 60 degrees from the spin axis. and focused the incoming light onto the Ebert-Fastie monochromator had a 3600 line/mm diffraction grating, with 15 Angstrom spectral resolution and 4.4 angstrom grating steps. It had two exit slits, which passed the dispersed light to two photomultiplier tubes, to convert the light into electrical impulses. One tube was sensitive to UV wavelengths from 1100 to 1900 Angstroms, while the other one covered wavelengths from 1900 to 3600 angstroms. Counting could be done up to 2 Hz, it could store up to 256 words of data, and an integration period of 4, 8, 16, or 32 ms, determined by ground command. The instrument had three primary modes of operation: spectral, wavelength, and, Lyman-Alpha.
• instrument : Butterfield Wind Tunnel, Whitehead Aeronautical Laboratory, Queen Mary University of London, UK
  The Butterfield Wind Tunnel is an open circulation, suction-style wind tunnel with length of 3 m and cross-sectional area of 0.16 by 0.16 m. Graeme Butterfield was associated with the Department of Geography and with Aerospace Engineering at Queen Mary and Westfield College, University of London, merged in 1989 to be Queen Mary University of London, UK.

Result pages:  274  275  276  277  278  279  280  281  282  283  284  285  286  287  288  289  290  291  292  293