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Creating Small Satellite Constellations Around The Sun, C. Mclain, M. Martinez-Sanchez, G.R. Ricker
Creating Small Satellite Constellations Around The Sun, C. Mclain, M. Martinez-Sanchez, G.R. Ricker
Small Satellite Conference
This paper deals with the propulsion and trajectory issues of creating a small satellite constellation around the Sun. The possible uses for such a constellation, including stereoscopic imaging of the Sun and gamma ray burst localization, are briefly discussed. The focus of the paper is then narrowed to a range of orbits and payload masses. Spread rate, the most important parameter for creating a sun orbiting constellation, is explained and defined. Next, it is shown that impulsive chemical propulsion is better than low thrust electric propulsion for this mission class. Finally, a full discussion of the propulsion and trajectory options …
Microprocessor Technology And Single Event Upset Susceptibility , L.D. Akers
Microprocessor Technology And Single Event Upset Susceptibility , L.D. Akers
Small Satellite Conference
Today's small satellites employ powerful microcircuits to control virtually every aspect of the spacecraft. While these small devices are very capable, they are increasingly vulnerable to heavy ion induced Single Event Upset (SEU). Current technology is not very susceptible to SEUs. The evolution of microdevices is toward lower power and higher speed while spacecraft evolve toward smaller and lighter structures. This combination, along with the increased heavy ion particle fluence associated with large solar flares, will cause tomorrow's microdevices to experience SEU at rates approaching 100 upsets per device per day! To ensure mission success, these small satellites must consider …
Using Atmospheric Drag For Constellation Control Of Low Earth Orbit Micro-Satellites, Daniel Du-Toit, J.J. Du Plessis, W.H. Steyn
Using Atmospheric Drag For Constellation Control Of Low Earth Orbit Micro-Satellites, Daniel Du-Toit, J.J. Du Plessis, W.H. Steyn
Small Satellite Conference
In certain low Earth orbit (LEO) satellite missions it is required that two or more satellites must operate in a certain spacial configuration relative to each other. This paper introduces a simple concept of utilising aerodynamic drag to achieve this type of constellation control. A necessary structural requirement for the satellites is that a change in projected area on a plane perpendicular to the velocity vector of the satellite can be brought about by means of an orientation adjustment. The aerodynamic force acting on the satellite can thus be controlled through a simple eigenaxis slew of a three-axis stabilized satellite. …
A Multi-Channel Direct Conversion Digital Uplink Receiver, Ron Huebner, Nick Pappageorge, Lee Atkinson, Tom Seay, Erik Odeen, Ron Manherz, Stuart Golden
A Multi-Channel Direct Conversion Digital Uplink Receiver, Ron Huebner, Nick Pappageorge, Lee Atkinson, Tom Seay, Erik Odeen, Ron Manherz, Stuart Golden
Small Satellite Conference
The design details of a direct block-down converting receiver which provides simultaneous demodulation of up to seven uplink channels is presented. The overall architecture is that of a block down converting receiver utilizing a fixed tuned RF front end and a single conversion. The bandwidth of interest is complex down-converted to baseband into I and Q channels, and sampled by a high speed analog-to-digital converter. The digitized I and Q data is then input to a Fast Fourier Transform (FFT) processor to perform coarse channelization. Finally, filtering, channelization, and demodulation is performed within a digital signal processor (DSP) dedicated to …
Near Costing As A Template For Future Small Spacecraft Missions, J.T. Hemmings
Near Costing As A Template For Future Small Spacecraft Missions, J.T. Hemmings
Small Satellite Conference
On February 17, 1996, NASA solidified its "faster, better, cheaper" guidelines for low cost planetary missions with the successful launch of the Near Earth Asteroid Rendezvous (NEAR) spacecraft. A guide for future small spacecraft missions has now been established. NEAR, the first mission in NASA's Discovery Program for "faster, better, cheaper" planetary exploration and the first asteroid orbiter ever was designed and built at The Johns Hopkins University Applied Physics Laboratory (JHU/APL). The design emphasizes simplicity, reliability, and low cost. Discovery Program criteria include a cost ceiling of $150 million (FY 92 dollars) on spacecraft development to launch plus 30 …
Optical Design And Performance Of The Odin Uv/Visible Spectrograph And Infrared Imager Instrument, Gabriel Warshaw, Donna-Lee Desaulniers, Douglas Degenstein
Optical Design And Performance Of The Odin Uv/Visible Spectrograph And Infrared Imager Instrument, Gabriel Warshaw, Donna-Lee Desaulniers, Douglas Degenstein
Small Satellite Conference
Sweden's Odin international scientific small satellite is planned for launch into a sun synchronous low earth orbit in 1998. Odin's mission will be both astronomy and atmospheric science (aeronomy). Its principle aeronomy payload is a high performance, lightweight (12 kilograms) ultraviolet/visible imaging spectrograph and infrared imager, that will point at the limb of the earth's upper atmosphere and measure molecular species associated with ozone chemistry, detect aerosols and tomographically measure and map ozone. The Canadian Space Agency is funding this payload, which has the acronym "OSIRIS", and Routes Inc. is currently building the flight model. OSIRIS is effectively two optical …
A Meo-Geo Combined Earth Sensor/Sun Sensor, James Fallon, Gerald Falbel
A Meo-Geo Combined Earth Sensor/Sun Sensor, James Fallon, Gerald Falbel
Small Satellite Conference
This paper discusses the design and performance characteristics of a combined earth sensor/sun sensor for use in the MEO (13,000 km) to GEO orbital altitude range, including super GEO altitudes up to 77,000 km. This combined sensor has been developed for use on a current GEO spacecraft series, and has been delivered. The earth sensor provides a ±30° x ±15° acquisition range, an accuracy ±0.02°, and a highly linear readout range of ±6° x ±3°, over which this accuracy applies. The integral sun sensor, which is coaligned with the earth sensor, provides a ±60° azimuth x ±30° elevation sun readout …
Pyramid Coarse Sun Sensing For Nasa Ssti "Clark" Safe-Hold Mode, Jeff Benton
Pyramid Coarse Sun Sensing For Nasa Ssti "Clark" Safe-Hold Mode, Jeff Benton
Small Satellite Conference
This paper describes an innovative approach to solving the Sun-pointing problem using a pyramid configuration of Coarse Sun Sensor (CSS) cells. In safe-hold mode, the Small Spacecraft Technology Initiative (SSTI) Clark spacecraft must keep its solar arrays towards the Sun using only CSS cells to sense the Sun. Unfortunately, Earth albedo degrades the accuracy of the Sun vector from these cells. Two CSS configurations are considered. A traditional configuration has cells mounted flat on each spacecraft face, with their normals along the spacecraft body axes. An alternative configuration has cells on the face of a shielded pyramid as well as …
Streamlining Satellite Development, Testing, And Operations Using A Cots Command And Telemetry Package , Andrew Lewin
Streamlining Satellite Development, Testing, And Operations Using A Cots Command And Telemetry Package , Andrew Lewin
Small Satellite Conference
This paper discusses how modern, commercial off-the-shelf (COTS) command and telemetry packages and data analysis tools can reduce cost and tighten schedules. By including the ground station from the start of the program life cycle, organizations can improve efficiency through the parallelization of activities, reuse of program resources, improvement of processes, and elimination of development tasks. The benefits of this approach are substantial for a single program. However, corporations can realize even greater productivity when subsequent programs build upon the strong foundation created by their predecessors. The methods introduced in this paper are brought to life through the example of …
Progress Of The Development Of Whale Ecology Observation Satellite System, T. Hayasahi, H. Tomita
Progress Of The Development Of Whale Ecology Observation Satellite System, T. Hayasahi, H. Tomita
Small Satellite Conference
To reveal the ecology of some of the species of whales a Whale Ecology Observation Satellite (WOES) System are being developed, in which several ideas are exploited to realize a system with high cost performance.
The Ssti Lewis Better, Faster, And Cheaper Guidance, Navigation, And Control Subsystem , Paul Parry
The Ssti Lewis Better, Faster, And Cheaper Guidance, Navigation, And Control Subsystem , Paul Parry
Small Satellite Conference
The NASA Small Spacecraft Technology Initiative was among the first of the high performance, low cost spacecraft programs. It was NASA's postulate that by leveraging U.S. technology investments and minimizing customer management oversight, significant reductions in cost and schedule could be realized, while advancing the state of the art in spacecraft performance. Use of the latest in sensor, processor, and structures technology enabled the SSTI Lewis Guidance, Navigation and Control Subsystem to significantly improve its pointing capabilities over most lightsat programs. The combination of vastly reduced customer oversight, extensive subsystem heritage from previous programs, and the flexibility to use in-house, …
Local Vertical/Local Horizontal Attitude Control For Spartan Spacecraft, James Morrissey, David Olney
Local Vertical/Local Horizontal Attitude Control For Spartan Spacecraft, James Morrissey, David Olney
Small Satellite Conference
A Spartan spacecraft attitude control system was reconfigured to provide attitude pointing with respect to a Local Vertical/Local Horizontal reference frame even though the baseline system uses only an initial start attitude, sun sensors, and star tracker/gyros for defining the spacecraft attitude. No earth sensors of any kind are used. Deployed from the orbiter for two days, usually for solar and stellar inertial pointing, Spartan missions use pointing programs that must be written months prior to launch with bit-level changes possible only in the on-orbit period prior to deployment. With these limitations, Spartan missions 206 and 207, flown in 1996, …
A New Attitude Control Mechanism For Leo Satellites, Mark Krebs
A New Attitude Control Mechanism For Leo Satellites, Mark Krebs
Small Satellite Conference
ORBCOMM is a LEO communications spacecraft, providing global point to point packet messaging. Two are in operation now, and the rest of the (eventually 36) constellation design spacecraft are currently in integration and test. The ORBCOMM ACS mission is to point a communications antenna to nadir, while maintaining continuous Sun tracking via spacecraft yaw maneuvers. This mission is achieved using almost entirely magnetic control, providing a new standard of performance for this type of system. OSC's new design includes substantially improved attitude determination and control relative to the first two spacecraft. Using knowledge gained from the on orbit performance of …
Low-Cost Attitude Determination And Control For Small Satellites, J.L. Smith, C. Wood, K. Reister, D.J. Forrest, K. Levenson, W.T. Vestrand, C. Whitford, D. Watson, A. Owens
Low-Cost Attitude Determination And Control For Small Satellites, J.L. Smith, C. Wood, K. Reister, D.J. Forrest, K. Levenson, W.T. Vestrand, C. Whitford, D. Watson, A. Owens
Small Satellite Conference
This paper addresses the need to develop small satellite technology which will enable small satellites to perform large satellite missions. The Center for Aerospace Technology (CAST) at Weber State University (WSU) has an 18 year history of small satellite innovation. Previous satellites include: NUSAT, WEBERSAT, and PHASE 3d. CAST is currently fabricating two new small satellites with advanced capabilities. CATSAT, a USRA program, will determine the origin of gamma-ray bursts and is a joint project with the University of New Hampshire and the University of Leicister in England. JAWSAT, a joint project with the U.S. Air Force Academy, will be …
The Near Ground System: Efficient Mission Command And Control, Gary Whitworth, Anthony Somers, William Stratton
The Near Ground System: Efficient Mission Command And Control, Gary Whitworth, Anthony Somers, William Stratton
Small Satellite Conference
The Near Earth Asteroid Rendezvous (NEAR) mission is designed to place a spacecraft in orbit about the near-Earth asteroid Eros in January 1999. The February 17, 1996 launch was the first in the Discovery series of small planetary spacecraft missions. Designed in keeping with the intent of the Discovery program to reduce development and mission operations costs for planetary missions. The ground system command and control architecture consists of a single, flexible network, used commonly and simultaneously for Integration and Test (I&T) operations, launch operations, and Mission Operations. After a 27 month mission development program, NEAR Spacecraft Operations are conducted …
A Small Re-Entry Capsule - Brem-Sat 2, Matthias Wiegand, Hans Konigsmann
A Small Re-Entry Capsule - Brem-Sat 2, Matthias Wiegand, Hans Konigsmann
Small Satellite Conference
Following the successful end of the first BREM-SAT mission, BREM-SAT 2 will return back to Earth with a deployable heat-shield and a small solid rocket motor after its mission. A parachute and a small radio beacon are then used to find the satellite with the scientific data of its re-entry and the material samples of a microgravity solidification experiment. Most subsystems are taken from the flight-proven first BREM-SAT mission with minor adaptations to the new mission profile. Attitude control, power supply and onboard data handling will essentially remain unchanged, whereas the structural design incorporates most of the changes. The results …
Gps Navigation For Use In Orbits Higher Than Semisynchronous: A Look At The Possibilities And A Proposed Flight Experiment, M.D. Lester
Small Satellite Conference
The Global Positioning System (GPS) was originally designed for positioning and navigation uses on and near the Earth. Recent experiments have expanded the use of the GPS for orbit and attitude determination in low-Earth orbits. All of these uses are logical since GPS satellite broadcasts are always nadir pointing and the GPS orbit is higher than the receivers. This paper investigates using GPS signals for estimating satellite orbit parameters at altitudes above the GPS constellation of approximately 20,200km. Focus is given to the applicability of this technique to the United States Air Force Academy's (USAFA) lunar mission as a test …
Report On Alternative Devices To Pyrotechnics On Spacecraft, M. Lucy, R. Hardy, E. Kist, J. Watson, S. Wise
Report On Alternative Devices To Pyrotechnics On Spacecraft, M. Lucy, R. Hardy, E. Kist, J. Watson, S. Wise
Small Satellite Conference
Pyrotechnics accomplish many functions on today's spacecraft, possessing minimum volume/weight, providing instantaneous operation on demand, and requiring little input energy. However, functional shock, safety, and overall system cost issues, combined with emergence and availability of new technologies question their continued use on space missions. Upon request from the National Aeronautics and Space Administration's (NASA) Program Management Council (PMC) , Langley Research Center (LaRC) conducted a survey to identify and evaluate state-of-the-art nonexplosively actuated (NEA) alternatives to pyrotechnics, identify NEA devices planned for NASA use, and investigate potential interagency cooperative efforts. In this study, over 135 organizations were contacted, including NASA …
Smallsat Launch Options: Choices And Challenges, Matthew Bille, Erika Lishock
Smallsat Launch Options: Choices And Challenges, Matthew Bille, Erika Lishock
Small Satellite Conference
Affordable, reliable, and responsive launch is critical to the survival and growth of small satellite systems. Unfortunately, no small launch vehicle now on the U.S. market offers a perfect solution: low cost, proven reliability, and the flexibility to meet all user requirements. There are several small launchers on the market, and choosing the best launcher for a given mission is a difficult challenge for the smallsat developer. Using the launch of three sample smallsats as a mission model, this paper surveys launch vehicle options currently available or in advanced development. Those launch vehicles capable of launching the mission model satellites …
Results Of Low-Cost Electric Propulsion System Research For Small Satellite Application, T.J. Lawrence, J.J. Sellers, J.W. Ward, M. Paul
Results Of Low-Cost Electric Propulsion System Research For Small Satellite Application, T.J. Lawrence, J.J. Sellers, J.W. Ward, M. Paul
Small Satellite Conference
The paper summarises on-going research into lowcost electric propulsion system options for small satellite stationkeeping missions. An overview of system cost drivers, electric propulsion system trade-offs, and initial water resistojet experimental results is given. The propulsion system for the forthcoming UoSAT-12 minisatellite system is described. Future water resistojet research work is summarised.
Asusat 1 Communications, Laura Knauth
Asusat 1 Communications, Laura Knauth
Small Satellite Conference
An overview of the communications components involved in the ASUSat 1 mission is discussed. The ASUSat 1 satellite will communicate with the Arizona State University ground station via an RF link in both a digital and analog mode in two amateur radio bands. In this way, ASUSat 1 will function as a voice repeater for the AMSAT community as well as to provide digital packet communications for the purpose of transferring data between the satellite and the ground station.
The Data-Chaser Hitchhiker Project As A Demonstration Of Distributed Operations For Small Satellites, Ryan Shepperd, Jason Willis
The Data-Chaser Hitchhiker Project As A Demonstration Of Distributed Operations For Small Satellites, Ryan Shepperd, Jason Willis
Small Satellite Conference
DATA-CHASER consists of two synergetic projects, DATA and CHASER, which will fly as a Hitchhiker payload aboard the Space Shuttle in 1997. A technology experiment, DATA (Distribution and Automation Technology Advancement) seeks to advance human support technology. CHASER (Colorado Hitchhiker and Student Experiment of Solar Radiation) is a solar science experiment that serves to test DATA. The DATA technologies support cooperative operations distributed between different geographic sites as well as between humans and machines. Though demonstrated with a small Shuttle payload, such technologies apply equally well to small satellites.
Eor: A University Small Satellite For Low Cost Remote Sensing Of Ozone , Ellen Riddle
Eor: A University Small Satellite For Low Cost Remote Sensing Of Ozone , Ellen Riddle
Small Satellite Conference
The Educational Ozone Researcher (EOR) is a small scientific spacecraft designed by students of the Colorado Space Grant College (CSGC) at the University of Colorado at Boulder. EOR was a finalist in the Universities Space Research Association (USRA) Student Explorer Demonstration Initiative (STEDI) program and received Phase 1 funding in the amount of $160K during late 1994 and early 1995. This paper provides a description of the scientific rationale and the design of the EOR mission.
Design Of A Low-Cost Single-Board Computer System For Use In Low-Earth Orbit Small Satellite Missions, Dino Milani
Design Of A Low-Cost Single-Board Computer System For Use In Low-Earth Orbit Small Satellite Missions, Dino Milani
Small Satellite Conference
A single-board computer system created specifically to meet the demands of a new generation of small satellite missions is being designed, built and tested by students at the University of New Hampshire. The Satellite Single-Board Computer (SSBC) is an Intel 80C186 based system that is qualified for explicit use in low-earth orbit missions. The SSBC serves as a low-cost, high-quality alternative to commercially available systems which are usually very costly and designed for much harsher space environments. These "off-the-shelf' systems are normally out of price range for most very low-cost satellite projects. At the other end of the spectrum, however, …
Near Mission Operations: Demonstrated Strengths And Weaknesses Of A "Faster, Better, Cheaper" Program, R.C. Weir, R.L. Nelson, A.S. Posner, K.E. Williams, C.E. Williams, W.P. Knopf, W.A. Sellers, R.B. Dickey, J.A. Landshof, A.R. Molloy, B.J. Geldzahler, T. Leoutsakos
Near Mission Operations: Demonstrated Strengths And Weaknesses Of A "Faster, Better, Cheaper" Program, R.C. Weir, R.L. Nelson, A.S. Posner, K.E. Williams, C.E. Williams, W.P. Knopf, W.A. Sellers, R.B. Dickey, J.A. Landshof, A.R. Molloy, B.J. Geldzahler, T. Leoutsakos
Small Satellite Conference
The Near Earth Asteroid Rendezvous (NEAR) Mission was successfully launched on February 17, 1996 from Cape Canaveral Air Force Base. A small mission operations team of 8 to 12 people have controlled the NEAR spacecraft from the JHU/APL campus in Maryland since then, using Deep Space Network ground stations and NASCOM circuitry, a Commercial Off The Shelf (COTS) ground computer system, and a unique streamlined concept of operations. The primary science data gathering portion of the mission will not begin until rendezvous with the asteroid EROS in January 1999, but 3 exciting "bonus" science observations have already occurred: visible images …
Tradeoffs In Functional Allocation Between Spacecraft Autonomy And Ground Operations: The Near (Near Earth Asteroid Rendezvous) Experience, S.C. Lee, A.G. Santo
Tradeoffs In Functional Allocation Between Spacecraft Autonomy And Ground Operations: The Near (Near Earth Asteroid Rendezvous) Experience, S.C. Lee, A.G. Santo
Small Satellite Conference
Today's modem spacecraft often fly a computing power equivalent, or nearly equivalent, to the computing power available to the ground operations team. This enables the spacecraft to perform many functions autonomously that previously could only be planned and carried out from the ground. In some cases, this increased computing power is required to perform functions that must be carried out on the spacecraft. For example, fault detection and correction must be carried out on the spacecraft when the time scale of critical faults is shorter than the time between ground contacts. In many given function. In implementing these functions, tradeoffs …
Automating The Operations Of The Orbcomm Constellation, John Tandler
Automating The Operations Of The Orbcomm Constellation, John Tandler
Small Satellite Conference
The ORBCOMM system is the world's first commercial LEO two-way data communications system. The ORBCOMM system, when fully deployed, will use a constellation of small satellites to provide users with low-cost near-continuous data relay and position determination services on a seamless worldwide basis. Due to the large number of spacecraft, and the need to keep operational costs low, automation will play a significant role in the operation of the ORBCOMM constellation. This paper discusses the principle operational functions needed to maintain the ORBCOMM satellites, and the design process for detennining the degree of automation for each.
A Fully Implemented Semi-Automated Ground-Control System For The Terriers Satellite, Nicolas Groleau, Larry Kiser, Forrest Girouard, Allen Hopkins, Tom Morgan, Supriya Chakrabarti, Timothy Cook, Daniel Cotton, Paul Dell
A Fully Implemented Semi-Automated Ground-Control System For The Terriers Satellite, Nicolas Groleau, Larry Kiser, Forrest Girouard, Allen Hopkins, Tom Morgan, Supriya Chakrabarti, Timothy Cook, Daniel Cotton, Paul Dell
Small Satellite Conference
In a collaborative effort, NASA Ames Research Center, the University of California Berkeley, and Boston University have developed ground software for a small satellite. This paper describes the ground communication software, the data archiving and serving system, and the data display and satellite scheduling in sufficient detail to allow prospective small satellite operators to explore its possible use or extension.
A Low-Cost Wireless Power Transmission Experiment, Steven Deal, V. Coverstone-Carroll
A Low-Cost Wireless Power Transmission Experiment, Steven Deal, V. Coverstone-Carroll
Small Satellite Conference
A solar power satellite (SPS) is a satellite dedicated to collecting solar energy on orbit, transforming it into microwave or laser energy, and beaming it to a receiving station on the ground. The transmitted energy is converted into DC or AC power for consumer use. Even a test version of the SPS would be a challenging and expensive undertaking due to the amounts of energy which need to be collected. Satellites measured in hundreds of meters and hundreds of millions of dollars are required for an accurate demonstration. It has been suggested that useful measurements can be made for substantially …
Integrated Reentry And Penetrator Vehicle (Irpv) For Subsurface Soil Collection And Analysis On Mars, David Keese, Ron. Lundgren
Integrated Reentry And Penetrator Vehicle (Irpv) For Subsurface Soil Collection And Analysis On Mars, David Keese, Ron. Lundgren
Small Satellite Conference
The continued exploration of Mars is a high priority item within NASA's interplanetary science community. It has long been a desire of this group to define an experiment that would investigate the possible presence and location of water/ice beneath the Martian surface. Until recently, however, there has not been a flight experiment dedicated to achieving this goal. This paper describes a concept design effort conducted at Sandia National Labs in collaboration with JPL and CalTech that has produced a feasible flight system to investigate this question.