Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 25 of 25
Full-Text Articles in Entire DC Network
Hete Telemetry Ranging Subsystem, Greg Huffman
Hete Telemetry Ranging Subsystem, Greg Huffman
Small Satellite Conference
The HETE (High Energy Transient Experiment) satellite, a joint project between MIT Center for Space Research and AeroAstro, is a high energy gamma ray burst/X-ray/UV observatory platform. In order to provide accurate time stamping of gamma ray burst events, a clock accurate to within 100 Ils of Universal Time (UT) is required on the satellite. This paper presents a clock setting/ranging subsystem that is incorporated into the HETE telemetry system at no additional weight or power consumption. This method makes use of augmenting the data scrambler with a PN ranging code with unique words which allows accurate ranging and clock …
International Activities In Small Satellites; Comparisons With U.S. Programs, Brian Horais
International Activities In Small Satellites; Comparisons With U.S. Programs, Brian Horais
Small Satellite Conference
Despite relatively low levels of Government funding when compared with U.S. small satellite activities, the international small satellite community has achieved a number of impressive successes. These range from the impressive imagery transmitted from the University of Surrey's UoSAT-5 to the demonstrated small satellite launch system versatility and affordability of the Ariane Auxiliary Structure for Space Payloads (ASAP). Capabilities exist in a growing number of countries outside of the United States to design, fabricate, and in some cases launch small satellites into low earth orbit. Activities in India and Israel are being joined by emerging space programs in such countries …
Recent Status Of Small Satellite Study In Japan, Takashi Iida, Ryutaro Suzuki, Atsushi Nakajima
Recent Status Of Small Satellite Study In Japan, Takashi Iida, Ryutaro Suzuki, Atsushi Nakajima
Small Satellite Conference
This paper describes the recent status of small satellite study in Japan focusing on the activities of the Small Payload WorkShop (SPWS) which was established in January, 1990. The objectives of SPWS are to review the development of small satellite and its launching system, to study the possible mission, to exchange information, to pick up and study the issues to be solved and to contribute to the good and efficient development of the future plan of small satellite utilization in Japan. The discussion to initiate the SPWS is reviewed briefly. The paper describes the recent studies of small satellites missions …
Launch Vehicle Options For Small Satellite Systems , Robert Cullen
Launch Vehicle Options For Small Satellite Systems , Robert Cullen
Small Satellite Conference
The small satellite industry faces a special challenge when it comes to the selection of a launch vehicle. Given the limited number of dedicated lifters and a disadvantageous payload weight/cost ratio, the launch planner must often compromise satellite system performance to remain within the profiles of throw weight, altitude, inclination, and cost associated with the obvious choices of launch vehicles. This paper provides a detailed look at the world's inventory of launch vehicles, particularly those that are appropriate for use as dedicated lifters of small satellites and those that can accommodate small satellites as non-primary payloads. The term small satellite …
Increasing Space Access Availability For Small Payloads: The Pacastro Launch Vehicle , Rick Fleeter, Frank Mcloughlin, Ray Millst
Increasing Space Access Availability For Small Payloads: The Pacastro Launch Vehicle , Rick Fleeter, Frank Mcloughlin, Ray Millst
Small Satellite Conference
This paper familiarizes the Small Satellite community with the capabilities and advantages offered by the PacAstro launch vehicle and its applications to low-cost launch needs. At a projected cost of $5M per launch, the 2-stage, pressure-fed liquid fueled vehicle is designed to transport 225 kg (500 Ibm) to a 750 km (405 nm) altitude circular polar orbit, or to a 1200 km (650 nm) altitude circular equatorial orbit. The smooth burning engine provides a gentle vibration environment and can be throttled, shut-down, and restarted to accommodate accurate orbit insertion. The large 1.5 m 10 and 2.4 m long payload volume …
Missions Of Small Satellites Launched By The J-I Launch Vehicle , Atsuo Tsuiki, Toshio Doura, Yoshiaki Suzuki
Missions Of Small Satellites Launched By The J-I Launch Vehicle , Atsuo Tsuiki, Toshio Doura, Yoshiaki Suzuki
Small Satellite Conference
This paper presents the concept of the small satellites launched by the 1-1 launch vehicle of the National Space Development Agency of JAPAN (NASDA). On this concept, the missions of the small satellites are for the experiment and the validation of the earth observation. The satellite communications, and the others on orbit. For efficient achievements of these missions, the common satellite bus will be adopted for the solid launch vehicle J-I, in order to develop the each small satellite system quickly by low-cost.
Achieving Performance Taliorability In The Castor 120 Solid Rocket Motor, David Buhaly
Achieving Performance Taliorability In The Castor 120 Solid Rocket Motor, David Buhaly
Small Satellite Conference
The methods used by Thiokol Corporation to achieve unprecedented performance tailorability in the Castor 120™ solid rocket motor will be discussed.. This motor is a 120,000-pound class motor designed for use on expendable launch vehicle systems. It employs a carbon-epoxy composite case, Class 1.3 HTPB propellant, and a vectorable nozzle. A key objective was to build a motor that could be used in fast stage, strap-on, and second stage applications. Each application has differing thrust, action time, nozzle vector duty cycle. and structural capability requirements. In contrast, most existing large solid rocket motors are designed for a single application. With …
The Development Of The Northern Satellite Service, Rolf Skatteboe
The Development Of The Northern Satellite Service, Rolf Skatteboe
Small Satellite Conference
Launch- and operational cost have been prohibiting factors for small satellite systems. and it is becoming clearer that a new philosophy must be adopted to accommodate the reduced budgets of such systems. This paper discusses the design of an integrated launch facility for small polar orbiting satellites and sounding rockets. It focuses on the development of a cost-effective total service for integration, launch, operation and TT&C for micro-satellites, called the Northern Satellite Service (NSS). The goal is to create a flexible service, and offer this service to the international market The proposed launch facility is based on the existing infrastructure …
Launch Vehicle Technology And The Impact Upon Lightsat Design, Jason O'Neil
Launch Vehicle Technology And The Impact Upon Lightsat Design, Jason O'Neil
Small Satellite Conference
Low cost satellites require low cost access to space. Today, several companies are attempting to provide competitive launch services for small satellites. DSI, which has launched 18 lightweight satellites, has extensive experience in the areas of satellite design, launch planning, integration and test. The selection of an ELV has important impacts upon the design of the satellite. This paper focuses on 2 areas: 1.) the environments of the small ELVs and 2.) The corresponding impacts upon the satellite design. The author uses recent flight experiences to create a template which the designer can use to better understand the engineering constraints …
Single Event Upset And Latchup Sensitive Devices In Satellite Systems , Richard Maurer, James Kinnison
Single Event Upset And Latchup Sensitive Devices In Satellite Systems , Richard Maurer, James Kinnison
Small Satellite Conference
We present a decision tree to systematically evaluate the potential use of single event sensitive devices in spacecraft systems. We present several concrete examples of branches on the tree.
Resistance To Satellite Failures Of Leo Communication Systems , Thomas Wolf, Jean-Jacques De Ridder
Resistance To Satellite Failures Of Leo Communication Systems , Thomas Wolf, Jean-Jacques De Ridder
Small Satellite Conference
This paper presents a satellite failure analysis for Low Earth Orbit (LEO) constellations with continuous global coverage. Worst case failure configurations are identified for polar orbit constellations and the coverage performance deterioration 'is evaluated by computer simulations. Then, the probability of having a number of satellite failures in a given constellation is evaluated as a function of satellite reliability. It is shown that the probability of occurrence of a worst case failure configuration is very low, and that the most probable configuration is a uniform distribution of the defective satellites. As a consequence, the maximum tolerable number of satellite failures …
Low-Cost Quick-Look Radiation Testing Of Electronic Components For The Mars Observer Camera , S.M. Brylow, T.A. Soulanille
Low-Cost Quick-Look Radiation Testing Of Electronic Components For The Mars Observer Camera , S.M. Brylow, T.A. Soulanille
Small Satellite Conference
The development of modern electronics has far outstripped the inventory of components for which radiation tolerance has been determined and published. New component characteristics require a more integrated approach to radiation tolerance in system design. The Mars Observer Camera performance requirements could not be met with a design restricted to components of established radiation hardness. A balanced approach that intimately involved radiation effects in the system design process was required. This included low-cost, quick turnaround testing of total ionizing dose and heavy ion induced single event phenomena of upset and latchup. The results were used to inform the system design, …
Using Digital Signal Processors On Small Satellites, Don Lefevre, Daniel Mulally, Mark Heiberger
Using Digital Signal Processors On Small Satellites, Don Lefevre, Daniel Mulally, Mark Heiberger
Small Satellite Conference
Digital Signal Processing integrated circuits (DSPs) have improved terrestrial communications systems by allowing the implementation of greatly improved transmitters and receivers. In applications from dial-up modems, to echo-free conference phones, to customer-specific hearing aids, DSPs have allowed the implementation of functions that would be impractical without them. However, DSPs have had limited use in small satellites due to lower available data rates and relatively high power consumption. Also, most of the existing DSPs have not been space qualified. Improvements in semiconductor processes are allowing the construction of integrated circuits (ICs) with much smaller features. In fact, 0.6 micron processes are …
A Laser Downlink For Small Satellites Using An Optically Modulating Retroreflector, Gary Jensen, Charles Swenson
A Laser Downlink For Small Satellites Using An Optically Modulating Retroreflector, Gary Jensen, Charles Swenson
Small Satellite Conference
This paper presents an earthsatellite-earth laser downlink system which is compact, simple, and low-power enough to be considered for use on very small satellites. Presented here is the design, feasibility study, and results from preliminary "proof of concept" testing of the critical components.
Precision Quartz Oscillators And Their Use In Small Satellites, J.R. Norton, J.M. Cloeren
Precision Quartz Oscillators And Their Use In Small Satellites, J.R. Norton, J.M. Cloeren
Small Satellite Conference
Space-qualified precision quartz oscillators are ideal instruments for use aboard small satellites as the heart of the spacecraft navigation system as well as for other applications such as radio science experiments, pseudorandom communications, and altimetry. This paper provides information on the history of precision quartz oscillator use aboard small satellites and discusses potential applications and design tradeoffs. The Johns Hopkins University Applied Physics Laboratory pioneered the use of precision quartz oscillators in small satellites in 1958. Current performance parameters of oscillators designed by the Applied Physics Laboratory will be presented along with mass and power considerations.
Magnetic And Momentum Bias Attitude Control Design For The Hete Small Satellite , Daniel Chang
Magnetic And Momentum Bias Attitude Control Design For The Hete Small Satellite , Daniel Chang
Small Satellite Conference
A design study of the attitude control system for the High Energy Transient Experiment (RETE) small satellite is presented. The satellite is 3-axis stabilized and sun pointing, with stringent pointing stability requirements. For actuation, magnetic torquers and a momentum wheel are chosen for their technological maturity and lack of consumables. One science instrument (CCD UV camera) and sun sensors provide attitude measurement. Two complimentary control strategies are implemented to maximize controllability given the expected wide variation in Earth field direction. As this actuator complement is particularly suitable for a variety of small satellite missions, the design guidelines presented here should …
Populating The Abyss-Investigating More Efficient Orbits -Or- "Getting More Miles To The Gallon For Your (Space) Vehicle" , John Draim, Thomas Kacena
Populating The Abyss-Investigating More Efficient Orbits -Or- "Getting More Miles To The Gallon For Your (Space) Vehicle" , John Draim, Thomas Kacena
Small Satellite Conference
Most satellites operating in orbit are spatially distributed in one of the following regions: LEO (below 600 nm and below), MEO (Molniya and GPS), and GEO (synchronous circular). Other than Molniya and a few similar systems, little use has been made of either elliptic orbits or the 'middle-ground' orbits lying between 600 nm and synchronous altitude. This paper explores the potential for exploiting these less populated regions and demonstrates that analyzing system optimization parametrically may in fact, also dictate an increasing interest in this new territory. A non-dimensional coverage parameter is presented which indicates that the 'efficiency' of an orbit …
The Space Test Program Apex Mission Satellite , Frank Knight
The Space Test Program Apex Mission Satellite , Frank Knight
Small Satellite Conference
An overview is presented of the Air Force Space Test Program's Advanced Photovoltaic and Electronic Experiments (APEX) Mission. APEX will provide spaceflight for three military experiments on the fourth flight of the Pegasus Air-Launched Vehicle in ready 1993. The APEX spacecraft is Orbital Sciences Corporation's "PegaStar" integrated third stage, in which components of the final stage of the launch vehicle are augmented to provide a fully-functional, 3-axis stabilized experiment platform. The spacecraft configuration and capabilities are described. The mission development history to date is outlined, as is the vehicle processing prior to launch. Finally, plans for the distribution of experiment …
Near Earth Asteroid Rendezvous, Edward Reynolds, Robert Farquhar
Near Earth Asteroid Rendezvous, Edward Reynolds, Robert Farquhar
Small Satellite Conference
The Johns Hopkins University Applied Physics Laboratory recently completed a pre-Phase A study to design a spacecraft to rendezvous and go into orbit around a near earth asteroid. The spacecraft would map the asteroid's surface and collect other science data for a one year period. The primary mission would be a rendezvous with either asteroid Anteros or with asteroid 1982XB. Presently, the APL NEAR spacecraft is beginning Phase A study. This paper identifies the science objectives and mission goals, outlines the mission scenario, and concludes with a description of the APL NEAR pre-Phase A spacecraft.
Exploration Of Fuel Objects In Space Very Near Earth, Anthony Zuppero, Michael Jacox
Exploration Of Fuel Objects In Space Very Near Earth, Anthony Zuppero, Michael Jacox
Small Satellite Conference
A prospecting plan is presented to assay near Earth objects (NEO) for their potential to yield rocket fuel. The plan calls out small satellites as the near-term means to achieve low cost surveys and deep subsurface sampling of NEO composition. The water bearing classes of NEO to be considered are limited to those accessible in short time and with small thrusters. These include the water bearing clay objects (phylosilicates) at nearly trivial distances from Earth, and the recently identified water ice objects such as comet (#4015) 1979 VA. These objects are evaluated as small satellite prospecting and assay vehicle targets.
Exploration Of Pluto: Search For Applicable Small Satellite Technology, Robert Staehle, John Carraway, Christopher Salvo, Richard Terrile, Stacy Weinstein, Elaine Hansen
Exploration Of Pluto: Search For Applicable Small Satellite Technology, Robert Staehle, John Carraway, Christopher Salvo, Richard Terrile, Stacy Weinstein, Elaine Hansen
Small Satellite Conference
Pluto is the last known planet in our Solar System awaiting spacecraft reconnaissance. In its eccentric orbit taking it 50 AU from the Sun, Pluto presently has a thin atmosphere containing methane, which is projected to "collapse" back to the icy planet's surface in about three decades, following Pluto's 1989 perihelion pass at 30 AU. Based on ground and Earth-orbit-based observing capabilities limited by Pluto's small size and extreme distance, present top-priority scientific questions for the first mission concern Pluto and Charon's surface geology, morphology and composition, and Pluto's neutral atmosphere composition. Budgetary realities preclude a large, many-instrument flyby spacecraft, …
Copernicus - Lunar Surface Mapper, Frank Redd, Shaun Anderson
Copernicus - Lunar Surface Mapper, Frank Redd, Shaun Anderson
Small Satellite Conference
The Utah State University (USU) 1991-92 Space Systems Design Team has designed a Lunar Surface Mapper (LSM) to parallel the development of the NASA Office of Exploration lunar initiatives. USU students named the LSM "Copernicus" after the 16th Century Polish astronomer, for whom the large lunar crater on the face of the moon was also named. The top level requirements for the Copernicus LSM are to produce a digital map of the lunar surface with an overall resolution of 12 meters (39.4 ft). It will also identify specified local surface features/areas to be mapped at higher resolutions by follow-on missions. …
The Space System For The High Energy Transient Experiment, Bob Dill, Rick Fleeter, Richard Warner, Francois Martel, George Ricker
The Space System For The High Energy Transient Experiment, Bob Dill, Rick Fleeter, Richard Warner, Francois Martel, George Ricker
Small Satellite Conference
The High Energy Transient Experiment (HETE) is an astrophysics project funded by NASA and led by the Center for Space Research (CSR) at the Massachusetts Institute of Technology (MIT). It has for principal goal the detection and precise localization of the still mysterious sources of gamma ray bursts. The project is original in many respects. HETE will provide simultaneous observations of bursts in the gamma, X-ray and UV ranges from the same small (250 Ibms) space platform. A network of ground stations around the world will diffuse in real time key information derived from HETE observations to many ground observatories, …
Mapping Of Earth's Magnetic Field With The Ørsted Satellite, W.R. Baron, K. Leschly, P.L. Thomsen
Mapping Of Earth's Magnetic Field With The Ørsted Satellite, W.R. Baron, K. Leschly, P.L. Thomsen
Small Satellite Conference
The Danish Ørsted satellite will carry three science experiments with the objectives of mapping the Earth's magnetic field and measuring the charged particle environment from a 7801an altitude sun-synchronous polar orbit. The science data generated during the planned one year mission will be used to improve geomagnetic models and study the auroral phenomena. Comprehensive and accurate mapping of the geomagnetic field every 5 to 10 years is of particular interest to geophysical studies. As such, the Ørsted science data return will complement the Magsat (1979-80) and Aristoteles (=2000) mission objectives. Two magnetometers will be mounted on an 8 meter long …
The Development Of A Small Satellite Attitude Control Simulator, Rees Fullmer, Glen Peterson, Walter Holmans, Jay Smith, Jim Nottingham, Shaun Anderson, Tanya Olsen, Frank Redd
The Development Of A Small Satellite Attitude Control Simulator, Rees Fullmer, Glen Peterson, Walter Holmans, Jay Smith, Jim Nottingham, Shaun Anderson, Tanya Olsen, Frank Redd
Small Satellite Conference
Utah State University has developed an air bearing table to simulate the attitude dynamics of a small satellite. The Small Satellite Attitude Control Simulator (SSACS) table includes attitude sensors, a control computer, movable mass units and gas jet thrusters. This paper describes the design of the SSACS table and provides preliminary experimental results from 3 axis control tests.