Transportation
Thermal Systems Engineering Design and Analysis of a High Usability Host Spacecraft
Recent efforts in space exploration have focused on budget solutions for monitoring Earth’s climate and astrophysics. Implementing such a satellite requires thermal design in order to maintain the scientific instruments and bus components within their ideal operating temperatures. This paper outlines the thermal system’s engineering design and thermal analysis for a High Usability Host Spacecraft. Preliminary thermal engineering results suggest that the High Usability Host Spacecraft concept proposed herein is viable for low-cost scientific instrumentation satellite based missions.
Space-borne Passive Microwave Remote Sensing of Soil Moisture: A Review
Soil moisture (SM) plays an important role in groundwater recharge runoff air moisture atmospheric temperature land degradation geo-chemical process surface and sub-surface biota including agriculture etc. Several studies have reported comparable results of space-borne passive microwaves remote sensing of surface (2 to 5 cm) SM using relationship between volumetric SM and brightness temperature dielectric constant polarimetry roughness parameter mathematical inferences etc. However reported success studies are very site- image - overpass time- model- and situation specific and insufficient to reach at global conclusions. Therefore reported methods techniques and algorithms should thoroughly be tested in different biophysical environments to assess applicability in SM retrievals using microwave data captured at different frequencies polarization angle time etc.
Robust Aligned Carbon Nanotube Tape with Excellent Piezoelectric Properties
We report a highly aligned multiwalled carbon nanotube (MWCNT) tape with a P(VDF-TrFE) matrix that is mechanically robust and has excellent piezoelectric properties for sensor applications including but not limited to vibration gyroscopes and accelerometers. The tapes were tested for piezoelectric response via hysteresis measurements and d33 measurements. It was found that 10 weight percent P(VDF-TrFE) in a solution of DMSO resulted in increased values of dielectric constant piezoelectric coefficient and mechanical properties. The d33 value for the CNT/P(VDF-TrFE) was 70 pm/V which is approximately twice that for pure P(VDF-TrFE) film. Adding 10 weight percent BaTiO3 nanoparticles (100nm) increased the piezoelectric d33 value to 81 pm/V. These results are attributed to Maxwell-Wagner-Sillars polarization. This material has a tensile strength of 120 MPa and a Young’s modulus of 17.8 GPa.
High Energy Particle Generation in Cosmic Rays and Solar Particle Events
It is assumed that cosmic rays and other high-energy particles of extraterrestrial origin can be produced by first-order Fermi diffusive shock acceleration in plasma up to 5x1019 eV the point where they interact with the cosmic microwave background (CMB). First-order Fermi shock acceleration is due to a supersonic shock with a Mach number dependent on the index (or logarithmic slope) of the shock-induced power-law spectrum. The local all-particle interstellar cosmic-ray spectrum can be obtained from the solution of a Fredholm integral equation in rigidity yielding both the “knee” and the “ankle” of the primary spectrum. The effect of the maximum galactic acceleration mechanism at high energies near the ankle is to increase the relative number of heavy nuclei relative to protons. Multiple cutoffs of heavier nuclei due to interactions with the CMB have the opposite effect just below the Greisen-Zatsepin-Kuz’min (GZK) cutoff resulting in fluxes enriched in protons. Earthward-directed supersonic coronal mass ejections are responsible for the great bulk of high-energy solarparticle events because of diffusive shock acceleration in the heliosphere.
Lorentz Invariance and the Global Positioning System
An example is considered (clock riddle) which demonstrates that opposite results are obtained for the length of an object depending on whether FitzGerald-Lorentz contraction (FLC) is assumed or instead the determination is based on the elapsed time required for a light pulse to traverse between its endpoints. This lack of internal consistency in relativity theory is traced to an undeclared assumption Einstein made regarding a normalization factor appearing in his original derivation of the Lorentz transformation (LT). If the empirical relationship between clock rates employed in the methodology of the Global Positioning System (GPS) is used to fix the value of this factor an alternative Lorentz transformation (ALT) is shown to result that removes the above inconsistency while still satisfying Einstein’s two postulates of relativity and remaining compatible with Einstein’s relativistic velocity transformation (VT) as well.
The Possibility to Construct a Graser – High Sensitivity Gravitational Wave Detector by Using the Electrogravitic Property of Dielectric Materials
Astronomers tried to detect gravitational waves which are generated by the movement of massive astronomical bodies. However it is very difficult to detect gravity waves by using conventional devices. Leon Brillouin proposed a concept of Graser that is a powerful amplifying device for gravity waves which can enable us to measure gravity waves their frequencies their velocities and how they propagate. According to the theory by Boyko Ivanov the gravitational field can be induced by an external electric field for a dielectric material. By studying Ivanov’s formulas the author has obtained the result that a gravitational wave detector consisting of a dielectric material which has a higher sensitivity and a smaller size compared with the conventional gravitational detector can be constructed.
A Power Budget Model for Highly Adaptive Small Satellites
Small satellite power is a critical space segment resource that is at a premium. This is especially obvious when considering highly adaptive small satellites (HASSs) that exhibit static and active (dynamic) power regimes. Reconfigurable spacecraft modules and subsystems have been patented spanning core bus payload propulsion and deployment interface. The majority depends on static power margins for specific mission requirements. This paper reports a system-level power budget (PB) model for the HASS system. It beacons on the power-to-mass ratio payload power requirement adaptive device technology used power contingency factor and core bus subsystem power consumption. Spacecraft power estimating relationships (PERs) that satisfy the next-generation small satellite system engineering requirements have been developed based on past missions. A case study of a meteorological mission in low earth orbit is presented. Furthermore field programmable gate array power regimes measurements were done to assess the power requirements of the active device. 90 mW of differential dynamic power was observed to represent 2.8 % of a 5-kg highly adaptive small nanosatellite power margins in low earth orbit (LEO). The presented results reveal that the HASS power margin must be at least equal to the designed maximum baseline power margin. A space mission can be stalled if the inorbit dynamic power increases beyond the designed maximum allowable power margin. The proposed HASS PB model enhances the design of reliable and high performance solar panels at first sight for deterministic space operations.
Printed Thermoelectric Generator for Hybrid Tandem Photovoltaic/ Thermoelectric Device
An analysis of the patented technology related to the use of conventional sources of energy is presented and the benefits offered by renewable energy systems are outlined. Current trends of patents on energy conversion technology show that the combination of two or more different forms of energy could surpass the limits of each individual conversion cycle. Photovoltaic solar cell tandem with thermoelectric generator is one of the examples. Thermal portion of the solar energy can be also extracted with a thermoelectric device to generate electricity. In the paper two types of solar thermal collectors (thermoelectric layer under the photovoltaic solar cell layer and thermoelectric tandem system under parabolic thermal energy collector) with thermoelectric ink and applications are presented. The solar thermal energy systems can be used for a wide range of applications including space mission.
Towards Space ‘Vacuum Technology’ in Virtually Open Space: Ultra- Low-Pressure (ULP) Inflatable Structures
Effective self-sustaining ‘vacuum technologies’ such as magnetron-enhanced plasma deposition processes may be realized in virtually open space separated from the cosmos by a flexible gas barrier inflated by the functional gas pressure required by those processes. The key challenging aspects of the design and functioning of Ultra-low-pressure (ULP) inflatable structures as well as their structural integrity in space environment including micrometeoroid attacks are addressed on a quantitative level and the main parameters are defined. It is shown that the transition from argon to xenon as a functional gas of vacuum technology would improve the gas barrier functionality of the ULP inflatable structures by one to three orders of magnitude. In conjunction with the recent advances in technology of elastomers this makes the ULP inflatable structures already realizable and practical. The article includes brief analytical reviews of the recent research and patent publications in the relevant fields from the aspect of ULP inflatable structures.
Doppler Asymmetric Spatial Heterodyne (DASH) Light Detection and Ranging (LIDAR) Receiver
The Doppler Asymmetric Spatial Heterodyne (DASH) spectrometer concept was first proposed in 2006 for measuring Doppler shifts of single or multiple near monochromatic signals and specifically for the passive measurement of atmospheric winds in planetary atmospheres. DASH interferometers have since been proposed built and used for the passive remote sensing of Doppler shifts of naturally occurring telluric airglow lines to infer thermospheric winds. In particular ground based measurements have been conducted and a space based DASH instrument payload for measuring thermospheric winds from low earth orbit is currently part of a NASA Explorer mission Phase A study. Up to now DASH interferometers have only been implemented and proposed for instruments that perform passive detection of naturally occurring thermospheric airglow. Using DASH interferometers within the active detection system of a Doppler wind Light Detection and Ranging (LIDAR) system was recently patented in the United States of America. This paper briefly explains this concept and its potential advantages.
Use of Remote Sensing Techniques for Robust Detection and Estimations of Soil Organic Carbon: A Review
Soil Organic Carbon (SOC) plays an important role in soil fertility complex water and nutrient exchange processes in plant root zone land degradation and global carbon cycle. Space technology is an efficient tool to: 1) estimate and map the SOC stocks and 2) rectify the stakeholders for enough food production and climate change management. Several studies and patents have reported complimentary results and successful applications of remotely sensed data for estimations of SOC at different resolutions techniques and approaches. However the results are susceptible to: 1) remotely sensed data quality and technical efficiency 2) sufficient number of samples representing variability of soils and land use 3) suitable methods and techniques selected for laboratory analyses of sampled soils and 4) selected methods and techniques for calibrations of spectra. Therefore reported success studies are very site- image- and situation-specific and insufficient to reach at global conclusions. The field is new active attractive challenging and interesting area of research for soil fertility and climate change management.