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Mars Surveyor Program And Uhf Telemetry Communications, Scott Toro-Allen, Christopher Anderson Sep 1996

Mars Surveyor Program And Uhf Telemetry Communications, Scott Toro-Allen, Christopher Anderson

Small Satellite Conference

Beginning in November 1996 with the launch of the Mars Global Surveyor (MGS), NASA will embark on a decade-long exploration of the planet Mars using a series of robotic spacecrafts. Launched approximately every 26 months, these probes will carry Orbiters, Landers, and Rovers with the intent of mapping the planet while characterizing its climate, along with a search for water and possible life, past or present. Severe budgetary constraints on these missions and their highly focused scientific objectives will require leading-edge technologies to achieve their aggressive goals. The MGS, along with the Pathfinder mission (a Lander with a small Rover), …

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Command And Data Handling Processor, James Perschy Sep 1996

Command And Data Handling Processor, James Perschy

Small Satellite Conference

This command and data handling processor is designed to perform mission critical functions for the NEAR and ACE spacecraft. For both missions the processor formats telemetry and executes real-time, delayed and autonomy-rule commands. For the ACE mission the processor also performs spin stabilized attitude control. The design is based on the Harris RTX2010 microprocessor and the UTMC Summit MIL-STD-1553 bus controller. Fault tolerant features added include error detection, correction and write protection memory. Components have been selected to minimize the possibility of charged particle induced upset. The processor's architecture and mechanical design are described. The hardware and software test and …

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Progress Of The Development Of Whale Ecology Observation Satellite System, T. Hayasahi, H. Tomita Sep 1996

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.

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Novel Collapsible Lens Antenna Design For Smallsat Applications, Nizar Sultan, Guy Seguin, Peter Wood Sep 1996

Novel Collapsible Lens Antenna Design For Smallsat Applications, Nizar Sultan, Guy Seguin, Peter Wood

Small Satellite Conference

When an antenna of large aperture is required for a small-satellite application, this antenna is most conveniently realized as a collapsible structure. This can be implemented as space-fed antenna (a reflector or lens). The lens antenna has particular advantages, because the lens can be realized in the form of thin copper circuits printed on a flexible membrane. A further advantage of the lens is that it is relatively insensitive to the exact surface profile which is achieved after deployment. Different types of printed structures have been analyzed in order to determine the optimal design strategy for a printed, collapsible lens. …

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Concepts For The Virtual Satellite Command And Control Network, Jim Brady Sep 1996

Concepts For The Virtual Satellite Command And Control Network, Jim Brady

Small Satellite Conference

A major obstacle to widespread deployment and use of small satellites is the cost of access to command and control facilities. While low-cost satellite earth stations are commercially available for receiving signals in bands associated with weather satellite broadcasts, the software and equipment required to upgrade these stations to perform command and control functions are prohibitive for many small satellite users. One alternative requires the leasing of satellite control facilities from commercial providers. By spreading the operating cost over several users, these facilities are less expensive, but often prone to logistical problems - there isn't usually one nearby. This paper …

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On-Board Autonomy For A Low Cost Lunar Mission, N.D. Monekosso Sep 1996

On-Board Autonomy For A Low Cost Lunar Mission, N.D. Monekosso

Small Satellite Conference

The lunar mission is to be Surrey Satellite Technology first step to interplanetary travel. SSTL has designed, built and launched twelve low cost microsatellites into LEO, starting in 1981 with UoSAT-1. Design of the next generation of low cost spacecraft, (250-400 Kg) is well underway, with UoSAT-12. This spacecraft is the first in a series of missions planned to qualify SSTL's minisatellite technology and to pave the way for the low cost lunar orbiter. The primary objective of this technology demonstration exercise is to show that low cost interplanetary missions are possible and to validate the minisatellite bus. In keeping …

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The Ssti Lewis Better, Faster, And Cheaper Guidance, Navigation, And Control Subsystem, Paul Parry Sep 1996

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, …

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Autonomous Constellation Maintenance System, John Collins, Simon Dawson, James Wertz Sep 1996

Autonomous Constellation Maintenance System, John Collins, Simon Dawson, James Wertz

Small Satellite Conference

At present, a large number of surveillance, scientific, and commercial communications constellations are being actively pursued by DoD, NASA, and the commercial space community. In many cases, these constellations will be made up of "LightSats" or small, low cost spacecraft. For such systems, operations costs, which are large in traditional systems, can become a dominant element of total system life cycle cost. This implies a need for low-cost autonomous constellation maintenance in order to allow such systems to be economically viable. A low-cost, autonomous approach for precisely maintaining the structure of Earth-orbiting satellite constellations from LEO to GEO is currently …

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A New Attitude Control Mechanism For Leo Satellites, Mark Krebs Sep 1996

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 …

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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 Sep 1996

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 …

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The Near Ground System: Efficient Mission Command And Control, Gary Whitworth, Anthony Somers, William Stratton Sep 1996

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 …

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Gps Navigation For Use In Orbits Higher Than Semisynchronous: A Look At The Possibilities And A Proposed Flight Experiment, M.D. Lester Sep 1996

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 …

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A Radiation-Hardened, Computer For Satellite Applications, John Gaona Sep 1996

A Radiation-Hardened, Computer For Satellite Applications, John Gaona

Small Satellite Conference

This paper describes high reliability radiation hardened computers built by Sandia for application aboard Department Of Energy (DOE) Satellite programs requiring 32-bit processing. The computers highlight a radiation hardened (1 Mrad(Si)) R3000 executing up to 10 Million Reduced Instruction Set Instructions (RISC) Per Second (MIPS), a dual purpose module control bus used for real-time fault and power management which allows for extended mission operation on as little as 1.2 watts, and a Local Area Network capable of 480 Megabits per second. The Central Processing Unit (CPU) is the NASA Goddard R3000 nicknamed the "Mongoose or Mongoose 1". The Sandia Satellite …

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Analysis Of Thruster Requirements And Capabilities For Local Satellite Clusters, G.J. Yashko, D.E. Hastings Sep 1996

Analysis Of Thruster Requirements And Capabilities For Local Satellite Clusters, G.J. Yashko, D.E. Hastings

Small Satellite Conference

This paper examines the propulsive requirements necessary to maintain the relative positions of satellites orbiting in a local cluster. Formation of these large baseline arrays could allow high resolution imaging of terrestrial or astronomical targets using techniques similar to those used for decades in radio interferometry. A key factor in the image quality is the relative positions of the individual apertures in the sparse array. The relative positions of satellites in a cluster are altered by "tidal" accelerations which are a function of the cluster baseline and orbit altitude. These accelerations must be counteracted by continuous thrusting to maintain the …

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Smallsat Launch Options: Choices And Challenges, Matthew Bille, Erika Lishock Sep 1996

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 …

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Advanced Pulsed Plasma Thruster Demonstration On Mightysat Flight Ii.1, D.L. Tilley, J.A. Pobst, D.R. Bromaghim, R.M. Myers, R.J. Cassady, W.A. Hoskins, N.J. Meckel, J.J. Blandino, D.E. Brinza, M.D. Henry Sep 1996

Advanced Pulsed Plasma Thruster Demonstration On Mightysat Flight Ii.1, D.L. Tilley, J.A. Pobst, D.R. Bromaghim, R.M. Myers, R.J. Cassady, W.A. Hoskins, N.J. Meckel, J.J. Blandino, D.E. Brinza, M.D. Henry

Small Satellite Conference

This paper describes the progress associated with a joint effort to demonstrate an advanced pulsed plasma thruster (PPT) on MightySat Flight II.1 to be launched in January, 1999. The PPT currently being developed for this flight represents a significant leap in technology compared to previous flight models. Although the MightySat II.1 launch vehicle is yet to be determined, the Space Shuttle Hitchhiker Eject System is the primary option under consideration. With this launch option, the PPT will be used to extend MightySat 11.1 life from about 1-3 months to over one year by raising its operational orbit. The PPT is …

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Results Of Low-Cost Electric Propulsion System Research For Small Satellite Application, T.J. Lawrence, J.J. Sellers, J.W. Ward, M. Paul Sep 1996

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.

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Asusat 1 Communications, Laura Knauth Sep 1996

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.

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The Data-Chaser Hitchhiker Project As A Demonstration Of Distributed Operations For Small Satellites, Ryan Shepperd, Jason Willis Sep 1996

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.

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Modifying Off-The-Shelf, Low Cost, Terrestrial Transceivers For Space Based Applications, Richard Lu Sep 1996

Modifying Off-The-Shelf, Low Cost, Terrestrial Transceivers For Space Based Applications, Richard Lu

Small Satellite Conference

The design, fabrication, and testing of low earth orbit satellite transceivers can get costly and time consuming for companies. As communication satellites proliferate, it is clear that lower cost materials, components, and processes will become standard procedure to stay competitive in the marketplace. This paper outlines the design and modifications done to off-the-shelf, terrestrial, ultra and very high frequency (UHF/VHF) communication equipment for just such a purpose. These low cost commercial products were successfully integrated and modified to survive the space environment. The work was accomplished by the Communications team of Stanford University's Space Systems Development Laboratories specifically to fly …

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Eor: A University Small Satellite For Low Cost Remote Sensing Of Ozone, Ellen Riddle Sep 1996

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.

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Design Of A Low-Cost Single-Board Computer System For Use In Low-Earth Orbit Small Satellite Missions, Dino Milani Sep 1996

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, …

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A Beacon Monitoring System For Automated Fault Management Operations, Michael Swartwout, Christopher Kitts Sep 1996

A Beacon Monitoring System For Automated Fault Management Operations, Michael Swartwout, Christopher Kitts

Small Satellite Conference

Stanford's Space Systems Development Laboratory (SSDL) has initiated a new space system technology initiative in order to develop, demonstrate, and validate a beacon monitoring system for spacecraft. This system consists of automated fault detection on board a spacecraft, a state of health beacon signal broadcast by the spacecraft, a ground based monitoring network, and a mission control center capable of efficiently integrating this health assessment strategy into its operating architecture. SSDL is investigating this technique by identifying fundamental design drivers, developing a system responsive to these drivers, and deploying the resulting system on micro spacecraft and within SSDL's developing, global, …

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Tradeoffs In Functional Allocation Between Spacecraft Autonomy And Ground Operations: The Near (Near Earth Asteroid Rendezvous) Experience, S.C. Lee, A.G. Santo Sep 1996

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 …

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Automating The Operations Of The Orbcomm Constellation, John Tandler Sep 1996

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.

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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 Sep 1996

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.

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Operations Concepts For Small Satellites - Results A Workshop, Erhard Rabenau, Wolfgang Klein, Hans-Jurgen Fischer Sep 1996

Operations Concepts For Small Satellites - Results A Workshop, Erhard Rabenau, Wolfgang Klein, Hans-Jurgen Fischer

Small Satellite Conference

The concept of small satellite missions has been promoted as a reaction to increasing budget cuts all over the world with the goal to reduce the overall cost for a mission considerably. On how mission operations can contribute to this goal and what are the recommendations was the theme of a workshop initiated by the German Space Agency DARA. Members from mission operations organisations, management, space industry and the user community were invited to share their knowledge and put forward ideas towards effective mission operations concepts for small satellites. The paper presents the results of the workshop comprising recommendations, suggestions, …

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A Low-Cost Wireless Power Transmission Experiment, Steven Deal, V. Coverstone-Carroll Sep 1996

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 …

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Integrated Reentry And Penetrator Vehicle (Irpv) For Subsurface Soil Collection And Analysis On Mars, David Keese, Ron. Lundgren Sep 1996

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.

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Pre-Flight Performance Of Sunsat, South Africa's First Remote Sensing And Packet Communications Microsatellite, A. Schoonwinkel, G.W. Milne, S. Mostert, W.H. Steyn, K. Van Der Westhuizen Sep 1996

Pre-Flight Performance Of Sunsat, South Africa's First Remote Sensing And Packet Communications Microsatellite, A. Schoonwinkel, G.W. Milne, S. Mostert, W.H. Steyn, K. Van Der Westhuizen

Small Satellite Conference

This paper describes the total system configuration, flight model components and pre-flight tests of the SUNSAT microsatellite which is to be launched in 1997. A very modular satellite mechanical structure has been constructed and environmentally tested. The first performance measurements of the payloads (a 15 m resolution imager, VHF, UHF, S and L band communications systems and space science experiments) are reported. The operation of the attitude determination and control system and other bus systems is described, indicating that a very complex microsatellite was developed as the first venture into space by a South African university. The microsatellite was built …

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