System-on-Chip for Real-Time Satellite Photovoltaic Curves Telemetry

This paper presents a System-on-Chip design for real-time satellites photovoltaic curves telemetry. In these applications, the limitation of memory and communication bandwidth makes quite difficult to store and to transmit the whole characteristic current-voltage (I–V) curve of any solar section in real-time. The proposed solution is based on the real-time calculation of the equivalent singlediode model of the solar section. The single-diode model fits accurately the behavior of any solar panel, so once the parameters are calculated, saved, and transmitted, at any working conditions, that specific curve could be later reproduced. The system is based on a LEON3 32-bit microprocessor core implemented in a Field Programmable Gate Array. The LEON microprocessors were originally designed by the European Space Agency, Paris, France, to be used in space projects where high reliability is required. In addition, in order to design the system as simple and reliable as possible, from all the methods available in the literature to extract the five parameters of the equivalent model, the Oblique Asymptote Method has been chosen for its simplicity and precision. Finally, some experimental results are presented to demonstrate the accuracy of the final system

SEDSAT 1 Advanced Photovoltaic Power System Technology Demonstration Flight

The University of Alabama in Huntsville Students for the Exploration and Development of Space, in cooperation with the NASA Marshall Space Flight Center, Boeing Defense & Space, and the Kopin Corporation, are designing an advanced electrical power system for a small satellite. This system incorporates recent advances in three areas: photovoltaic cell design, battery energy storage design, and DC·DC power conversion technology. Introducing these advances into a flight power system will produce a satellite power system with double the capability of similar systems utilizing current technology

Mass and power modeling of communication satellites

Analytic estimating relationships for the mass and power requirements for major satellite subsystems are described. The model for each subsystem is keyed to the performance drivers and system requirements that influence their selection and use. Guidelines are also given for choosing among alternative technologies which accounts for other significant variables such as cost, risk, schedule, operations, heritage, and life requirements. These models are intended for application to first order systems analyses, where resources do not warrant detailed development of a communications system scenario. Given this ground rule, the models are simplified to 'smoothed' representation of reality. Therefore, the user is cautioned that cost, schedule, and risk may be significantly impacted where interpolations are sufficiently different from existing hardware as to warrant development of new devices

ESTCube-1 electrical power system - design, implementation and testing

http://tartu.ester.ee/record=b2656616~S1*es

Multiprocessing techniques for unmanned multifunctional satellites Final report,

Simulation of on-board multiprocessor for long lived unmanned space satellite contro

Satellite on-board processing for earth resources data

Results of a survey of earth resources user applications and their data requirements, earth resources multispectral scanner sensor technology, and preprocessing algorithms for correcting the sensor outputs and for data bulk reduction are presented along with a candidate data format. Computational requirements required to implement the data analysis algorithms are included along with a review of computer architectures and organizations. Computer architectures capable of handling the algorithm computational requirements are suggested and the environmental effects of an on-board processor discussed. By relating performance parameters to the system requirements of each of the user requirements the feasibility of on-board processing is determined for each user. A tradeoff analysis is performed to determine the sensitivity of results to each of the system parameters. Significant results and conclusions are discussed, and recommendations are presented

Study of spin-scan imaging for outer planets missions

The constraints that are imposed on the Outer Planet Missions (OPM) imager design are of critical importance. Imager system modeling analyses define important parameters and systematic means for trade-offs applied to specific Jupiter orbiter missions. Possible image sequence plans for Jupiter missions are discussed in detail. Considered is a series of orbits that allow repeated near encounters with three of the Jovian satellites. The data handling involved in the image processing is discussed, and it is shown that only minimal processing is required for the majority of images for a Jupiter orbiter mission

SUNSAT, Stellenbosch University and SA-AMSAT\u27s Remote Sensing and Packet Communications Microsatellite

The Engineering Model of SUNSAT, a 50 kg, 45 cm, Ariane ASAP-compatible microsatellite is scheduled for assembly in December 1993, permitting flight model completion early in 1995. Fifteen M.Eng. students, led by Computer & Control System lecturers at Stellenbosch University, began detail design in January 1992. Most prototype hardware was operating by July 1993, and assembly of the first final-sized PCB\u27s started. A packet radio service, a 2m parrot speech transponder, and Mode A and S transponders, all defined and endorsed by SA-AMSAT, comprise the Amateur Radio communications payload. Verification of the 15-20 m pixel spacing, 3-color, 3456 pixel pushbroom imager capable of stereo imaging, is a major research goal. Data will be downlinked in S-band, or single images stored in a 64Mbyte RAM. Coarse attitude stabilization by gravity gradient and magnetorquing is improved by small reaction wheels during imaging. Continuous attitude sensing is by magnetometers. Sun sensors, visible band horizon sensors, and star sensor provide 1 mrad accuracy when imaging from the sun-synchronous orbit. Average power of 30 W enables images of South Africa to be taken on a daily basis for real time downlinking. Satisfaction of SA electronics companies on our Advisory Board with the engineering model will lead to continued student funding. Demonstration of a working engineering model will then hopefully provide the credibility we need to finalize a launch opportunity. The satellite\u27s layout, block diagram, and expected performance of the imager, downlink, and Amateur packet communications payload are described

NASA Innovative Advanced Concepts (NIAC) Phase 1 Final Report: Venus Landsailer Zephyr

Imagine sailing across the hot plains of Venus! A design for a craft to do just this was completed by the COncurrent Multidisciplinary Preliminary Assessment of Space Systems (COMPASS) Team for the NASA Innovative Advanced Concepts (NIAC) project. The robotic craft could explore over 30 km of surface of Venus, driven by the power of the wind

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs