Engineering topics
Narvaez, P.
Publications and source records attributed to Narvaez, P..
System level EMC testing of spacecraft
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An overview of results from the ion diagnostics sensors flown on DS1
The Deep Space 1 (DS1) mission has successfully validated the use of ion propulsion technology for interplanetary spacecraft. The NASA Solar Electric Propulsion (SEP) Technology Applications Readiness (NSTAR) Project developed the Ion Propulsion Subsystem (IPS) for DS1. As part of the NSTAR validation effort, the NSTAR Project included a diagnostics element to characterize the local environment produced during IPS operations and its effects on spacecraft subsystems and science instruments. An integrated, comprehensive set of diagnostics, the NSTAR Diagnostics Package (NPD) was developed and operated on DS1 to characterize the IPS environment. The DS1 Spacecraft Team officially assigned the name “IPS Diagnostics Subsystems (IDS)” to the NDP for the DS1 mission. During the technology validation phase of the DS1 mission, a large amount of data was collected from the IDS under a variety of IPS operating conditions. IDS was able to characterize the contamination environment, charge-exchange xenon ion and electron population and energies, plasma noise and electromagnetic noise, and magnetic fields associated with IPS. The results presented here describe the charge-exchange plasma, contamination, plasma wave/EMI, and DC magnetic environments critical to designers of future space missions using ion propulsion
First-Generation Jet Propulsion Laboratory "Hockey-Puck" Free-Flying Magnetometers for Distributed In-Situ Multiprobe Measurement of Current Density Filamentation in the Northern Auroral Zone: Enstrophy Mission
The sub-orbital rocket mission was a collaborative project between the University of New Hampshire, Cornell University, and the Jet Propulsion Laboratory (JPL) to study filamentation phenomena in the northern Auroral zone. The Enstrophy mission test flies the JPL Free-Flying Magnetometer (FFM) concept. The FFM technology development task has been funded by NASA develop miniaturized, low-power, integrated "sensorcrafts". JPL's role was to design, integrate, test, and deliver four FFMs for deployment from the sounding rocket, allowing a unique determination of curl-B. This provides a direct measurement of magnetic-field-aligned current density along the rocket trajectory. A miniaturized three-axis fluxgate magnetometer was integrated with a 4-channel 22-bit sigma-delta Analog to Digital Converter (ADC), four temperature sensors, digital control electronics, seven (Li-SOCl2) batteries, two (4 deg x 170 deg field of view) sun-sensors, a fan-shaped-beam laser diode beacon, a (16 MHz) stable Temperature Compensated Crystal Oscillator (TCXO) clock, Radio Frequency (RF) communication subsystem, and an antenna for approximately 15 minutes of operation where data was collected continuously and transmitted in three (3) bursts (approximately 26 seconds each) to ground station antennas at Poker Flat, Alaska. FFMs were stowed within two trays onboard the rocket during the rocket launch and were released simultaneously using the spinning action of the rocket at approximately 300 km altitude (approximately 100 sec. into the flight). FFMs were deployed with spin rate of approximately 17 Hz and approximately 3 m/sec linear velocity with respect to the rocket. For testing purposes while the rocket was in the launch pad and during flight prior to release of FFMs from the rocket, commands (such as "power on", "test", "flight", "power off', and clock "Reset" signal) were transmitted via a infrared Light Emitting Diode to an infrared detector in the FFM. Special attention was paid to low magnetic signature electronic design and choice of materials in packaging. The miniaturized fluxgate magnetometers had a range of 1-60000 nT with 0.1% full-scale linearity. The frequency range of interest for magnetic measurement was 10 mHz - 50 Hz. Digital data from the magnetometer's three axes were placed in a 4MB Static Random Access Memory (SRAM) in data packages (frames) formatted together with time tags and frame ID. After a specified time was elapsed, the data were Viterbi encoded and transmitted at a rate of 100 kbps (BPSK). Each of the four FFMs transmitted at different frequency. These carrier frequencies were in the range of 2200-2300 MHz. The antenna was a single patch on a high dielectric constant substrate covering one end-plate of the hockey-puck-sized unit. The local clocks aboard the FFMs were reset at the start of the mission and stayed synchronized within 3 msec during the mission. Position of each FFM with respect to the rocket is calculated by the knowledge of its release velocity (measured at exit point of the FFM launcher tract) providing an accuracy of 1 m over the maximum range of 3 km. Spatial and temporal nature of observants can be separated to within 3 m in space or 3 msec time interval.
Magnetostatic Cleanliness of the Radioistope Thermoelectric
This paper describes the field-mapping technique, the numerical modeling and the compensation approach used for the RTGs with the goal of minimizing its magnetic field interference with Cassini's DC magnetic field science instruments.
First Generation Jet Propulsion Laboratory *Hockey-Puck* Free-Flying Magnetometers for Distributed In-Situ Multiprobe Measurement of Current Density Filamentation in the Northern Auroral Zone: Enstrophy Mission
The sub-orbital rocket mission was a collaborative project between the University of New Hampshire, Cornell University, and the Jet Propulsion Laboratory to study filamentation phenomenon in the northern Auroral zone.
Multiprobe In-situ Measurement of Magnetic Field in a Minefield via a Distributed Network of Miniaturized Low-Power Integrated Sensor System for Detection of Magnetic Field Anomalies
Based on technologies developed for the Jet Propulsion Laboratory (JPL) Free-Flying-Magnetometer (FFM) concept, we propose to modify the present design of FFMs for detection of mines and arsenals with large magnetic signature.
Jet Propulsion Laboratory Free-Flying Magnetometers for Distributed In-Situ Multiprobe Measurement of Current Density Filamentation in the Northern Auroral Zone: Enstrophy Mission
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Cryocooler Electromagnetic Compatibility
Jet Propulsion Laboratory, under joint Ballistic Missile and Defense Organization/Air Force and NASA/Eos Atmospheric Infrared Sounder sponsorship is conducting extensive space cryocooler characterization to provide a reliable and accurate data base on cryocooler performance for use by the space community.