Human Development Report 2001: making new technologies work for human development

1: Introduction.- 2: Charged-Particle Motion in Magnetic and Electric Fields.- 3: Trapping Region and Currents Due to Trapped Particles.- 4: Electric Fields.- 5: Wave-Particle Interactions.

Quantitative aspects of magnetospheric physics

The high-energy particles of the Van Allen belts coming from cosmic rays, solar storms, and man-made processes pose a risk to humans and spacecraft operating in those regions These high-energy fluxes rapidly damage electronics, optics, and other systems The radiation belt remediation (RBR) concept has been proposed as a way to solve this problem through ULF/VLF transmissions in the magnetosphere capable of precipitating these energetic particles into the atmosphere This paper analyzes the effect of an RBR in-situ transmitter on inner belt energetic protons and outer belt electrons This interaction requires the radiation of the left-hand polarized electromagnetic ion cyclotron (EMIC) band from space-borne antennas The transmitter driving frequency and radiation pattern characteristics needed to drive the interaction are analyzed and applied to the calculation of individual test particles' scattering for different radiated power levels The results show that the effect of the transmitter on individual loss cone particles is up to three orders of magnitude smaller for inner belt protons than outer belt electrons While protons' scattering scales linearly with the wave field amplitude, electrons' scattering rapidly saturates because particles are being lost into the atmosphere A radiated power flux of 10-9 W/m2 at the source would require three days of continuous interaction to scatter near loss cone inner belt protons by 1°, and 02 s in the case of outer belt electrons If we increase the radiated power flux to 10-5 W/m2, this interaction is reduced to 30 s for protons and 35 milliseconds for electrons The engineering feasibility of EMIC transmitters is finally discussed; plasma contactors at both ends of a linear dipole antenna and magnetic loop arrangements are identified as possible EMIC in-situ transmitter solutions

Electromagnetic Ion Cyclotron Waves for Radiation Belt Remediation Applications

The Loss Cone Imager (LCI) instrument is part of the US Air Force Demonstration and Science Experiments (DSX) satellite and is comprised of three components: the Fixed Sensor Head (FSH), the High Sensitivity Telescope (HST), and the Central Electronics Unit (CEU). The emphasis of this paper is on the FSH, which is comprised of three Si solid state detectors (SSD) each comprised of six pixels capable of measuring incident particle energies (~ 30 keV - 500 keV) and their respective pitch angles. The FSH is mounted onto the exterior of the DSX Payload Module and covers a 180° by
10° view of the sky. Each pixel has a 10° by 10° field of view. Due to a small geometric factor, the FSH is able to operate
in the high particle flux areas of the Earth's magnetosphere. The Readout Electronics for Nuclear Application 3 (RENA3) chip, developed by NOVA R&D, contains 36 analog channels used for detection of nuclear events. Each of the 18 Si pixels is connected to a corresponding RENA3 channel for event detection and analog energy readout. The output of the chip is digitized and the digital value of each event, along with its corresponding RENA channel, is recorded by the Data Processing Unit housed in the CEU.

Overview of the Loss Cone Imager Fixed Sensor Head Instrument

The rapid deployment of satellites for responsive space surveillance applications is hindered by the need to flight-qualify their components and the resulting mechanical assembly. Conventional methods for qualification testing of satellite components are costly and time consuming. Furthermore, full-scale vehicles must be subjected to simulated launch loads during testing, and this harsh testing environment increases the risk of damage to satellite components during qualification. This work focuses on replacing this potentially destructive testing procedure with a non-destructive structural health monitoring (SHM)-based technique while maintaining the same level of confidence in the testing procedure's ability to qualify the satellite for flight. We focus on assessing the performance of SHM techniques to replace the high-cost qualification procedure and to localize faults introduced by improper assembly. The goal of this work is to create a dual-use system that can both assist in the process of qualifying the satellite for launch, as well as provide continuous structural integrity monitoring during manufacture, transport, launch and deployment. SHM techniques were applied on a small-scale structure representative of a responsive satellite. The test structure consisted of an extruded aluminum space-frame covered with aluminum shear plates assembled using bolted joints. Multiple piezoelectric transducers were bonded to the test structure and acted as combined actuators and sensors. Piezoelectric active-sensing based techniques, including measurements of low-frequency global frequency response functions and high-frequency wave propagation techniques, were employed. Using these methods in conjunction with finite element modeling, the dynamic properties of the test structure were established and areas of potential damage could be identified and localized. A procedure for guiding the effective placement of the sensors and actuators is also outlined.

https://iopscience.iop.org/article/10.1088/0957-0233/24/7/075101/pdf

Dynamic characterization of satellite assembly for responsive space applications

The High Sensitivity Telescope (HST) is a sensor comprising part of the Loss Cone Imager (LCI) on the DSXmission. The primary objective of the HST is to observe uxes of energetic electrons as small as 100 e cm 2 sr 1 s 1 within the Earths atmospheric loss cone. This is accomplished via a geometrical factor of 0 .1cm 2 sr combinedwith a collimator limiting the eld of view t o a 7 degree half-cone angle. The sensors are shielded to in order toreduce the background to levels permitting the detection of the stated ux. The HST will be looking for changesin this ux caused by events precipitating electrons into the atmosphere. Of primary interest are electronswith energies between 20 and 500 keV. The HST utilizes two fully depleted solid state detectors and threeanalog measurement chains. The primary detector is 1500 um thick and uses two measurement chains. A fastermeasurement chain for counting events at rates of 300k/sec and a slower measurement chain for measuring theenergy deposited by an event more accurately. The secondary detector is 1000 um thick and is used to detectevents that completely penetrate the primary detector. The analog electronics are built from discreet ampliers.Events on the faster primary chain are sorted into 5 energy bins. Events from the slow chain are digitized to8-bits of resolution.Keywords: Loss cone, magnetosphere, particle physics, solid state detectors, spacecraft instrumentation, wave-particle interaction

A high sensitivity telescope for measurements of energetic particles in the Earth's radiation belts

The Loss Cone Imager (LCI) will sample the energetic-particle pitch-angle distributions relative to the local geomagnetic field vector in the magnetosphere as a part of the Demonstration and Science Experiment (DSX) satellite. A description of the LCI electrical interfaces and data flow will be presented. The pitch angle and energy of energetic particles are recorded by the FSH (Fixed Sensor Head) and HST (High Sensitivity Telescope) sensor electronics using
solid state detectors. Energetic particle data must be extracted from the FSH and HST by the DPU (Data Processing Unit) and stored in a format that is practical for ground data analysis. The DPU must generate a data packet that is sent to the experiment computer containing science and housekeeping data, as well as receive ground and time commands from the experiment computer. The commands are used to configure the sensor electronics and change the data
acquisition periods of the science data. The instrument works in conjunction with the WIPER (Wave-Induced Precipitation of Electron Radiation) VLF (Very Low Frequency) transmitter on the DSX satellite to view the effects of VLF waves injected in the Earth's magnetic field on the precipitation of electrons into the Loss Cone. The system is designed to operate autonomously with the changing state of the transmitter to provide more appropriate data for examining the effects of the VLF transmitter.

Loss cone imager digital system design

A truly modular satellite design must be approached from a systems perspective in order to meet the Operationally Responsive Space (ORS) community's goal of a rapidly responsive spacecraft. In such a design approach, the modular mechanical bus system must complement a modular data bus system. Through the University Nanosatellite 5 competition, Boston University and Taylor University have built a comprehensive nanosatellite bus where each subsystem has followed a standardized electrical and mechanical interface. This standard is based on the CubeSat concept, but expanded to nanosatellites. It allows for instrument and subsystem designers to know the mechanical and electrical interfaces their instruments or subsystem must conform to prior to a mission, providing for ease of reuse for subsequent missions. Examples from the recently constructed Boston University Student Satellite for Application and Training (BUSAT) are given to illustrate the proposed standard and its capability for a rapid response.

A novel spacecraft standard for a modular nanosatellite bus in an operationally responsive space environment

A powerfully instrumented, reliable, low -cost, and 3 -axis stabilized nanosatellite is being developed as part of the Air Force University Nanosatellite -3 Program. The Thunderstorm Effects in Space: Technology (TEST) nanosatellite imple ments a new, highly modular satellite bus structure and common electrical interface that is conducive to satellite modeling, development, testing, and integration flow. TEST is a low -cost ($0.2 M) nanosatellite (30kg) in final development by Taylor Univer sity and the University of Illinois. TEST implements a variety of plasma, energetic particle, and remote sensing instrumentation with the objective of understanding how lightning and thunderstorms influence the upper atmosphere and the near -space environme nt. The TEST modular design and instrumentation challenges portions of satellite systems (such as future DOD DMSP and NASA LWS Geospace Missions), while complementing large multi -probe and remote sensing programs. TEST includes a variety of proven instrume ntation: two 1m Electric Field (EP) probes, a thermal plasma density Langmuir Probe (LP), a 5 to 100 kHz Very Low Frequency (VLF) Receiver, two large geometric factor cooled ( -60 ° C) Solid State Detector (SSD) spectrometers for energetic electrons and ions (10 keV< E <1 MeV), a 3 -axis Magnetometer (MAG), a O 2 Hertzberg UV Photometer, a 391.4 nm Transient Photometer and a 630 nm Imager for airglow and lightning measurements. In addition, the satellite is three -axis stabilized using CO 2 band horizon sensors, as well as a two -stage passive radiator for instrument cooling. TEST instrumentation and satellite subsystems are packaged in modular cubes of 10 cm increments. A common modular electrical interface board is used to standardize each of the subsystems for data flow, ground support, and data analysis.

David L. Voss

Papers

Overview of the Loss Cone Imager Fixed Sensor Head Instrument

A high sensitivity telescope for measurements of energetic particles in the Earth's radiation belts

Loss cone imager digital system design

A novel spacecraft standard for a modular nanosatellite bus in an operationally responsive space environment

TEST: A modular scientific nanosatellite