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Dataware; A Graphical Approach For Decoding And Displaying Small Satellite Data And Telemetry, George Starcher Aug 1991

Dataware; A Graphical Approach For Decoding And Displaying Small Satellite Data And Telemetry, George Starcher

Small Satellite Conference

Today's small satellites are capable of producing vast quantities of data from experiments and engineering telemetry. The requirements of the small satellite operator define how science and engineering data is treated. The small satellite operator typically does not have the financial resources for a worldwide network of downlink ground stations. These constraints require that the satellite's status must be ascertained within a relatively short window during a pass over a single or a few ground stations. Any anomalous operation needs to be quickly identified so that corrective action may be taken. In addition, the satellite operator is often the end …

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Optical Processing Of Microwave Signals For Small Satellite Payloads, Dan Sullivan Aug 1991

Optical Processing Of Microwave Signals For Small Satellite Payloads, Dan Sullivan

Small Satellite Conference

For low altitude small satellite applications performing electronic surveillance or communication transponding missions highly capable payloads are needed. Generally these spacecraft have low dwell times over the areas of interest and must receive, or search for, signals over a wide frequency band. This paper presents an approach to the implementation of optical processing in complex electronic systems intended to receive and operate on multiple radio frequency (or microwave) signals. The goal is to exploit the rapidly expanding field of linear and nonlinear optics to synthesize transponders and receiving systems for satellites and other platforms. The inputs are assumed to be …

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Space Science And Microsatellites - A Case Study Observations Of The Near-Earth Radiation Environment Using The Cosmic-Ray Effects And Dosimetry (Credo) Payload On-Board Uosat-3, C.J. Underwood., J.W. Ward, C.S. Dyer., A.J. Sims, J. Farren, J. Stephen Aug 1991

Space Science And Microsatellites - A Case Study Observations Of The Near-Earth Radiation Environment Using The Cosmic-Ray Effects And Dosimetry (Credo) Payload On-Board Uosat-3, C.J. Underwood., J.W. Ward, C.S. Dyer., A.J. Sims, J. Farren, J. Stephen

Small Satellite Conference

The University of Surrey's technology demonstration microsatellite: UoSAT-3 launched in January 1990. carries on-board a Cosmic-Ray Effects and Dosimetry (CREDO) payload for characterizing the low-Earth orbit (LEO) radiation environment. Measurements made with this payload are correlated with radiation effects observed in the spacecraft's microelectronics, in particular, the occurrence of single event upsets (SEUs) in solid-state memory devices. The CREDO payload consists of two Sub-systems, the Cosmic Particle Experiment (CPE) and the Total-Dose Experiment (TDE). The CPE houses an array of large-area PIN diode detectors, connected to a pulse-height analysis network. Particles incident on the detector are counted and logged according …

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Brem-Sat Attitude Control At Low Altitudes, Hans Koenigsmann, H. Rath, H. Oelze, A. Ginatii Aug 1991

Brem-Sat Attitude Control At Low Altitudes, Hans Koenigsmann, H. Rath, H. Oelze, A. Ginatii

Small Satellite Conference

The German University satellite BREM-SAT (scheduled for launch in early 1993) carries two experiments which require attitude control down to 150 km altitude and aerodynamic stabilization between 150 and 100 km altitude. These contradicting requirements and new ways to change the satellite's attitude and to keep it stable and controlled at very high disturbance torque levels. Complex numerical attitude simulation has shown the feasibility to maintain the required attitude with a momentum wheel and a single torque coil down to 150 km when optimized algorithms are used. To achieve the aerodynamic stabilization, the momentum wheel has to be ejected and …

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The Webersat Camera: An Inexpensive Earth Imaging System, Stephen Jackson, Jeffrey Raetzke Aug 1991

The Webersat Camera: An Inexpensive Earth Imaging System, Stephen Jackson, Jeffrey Raetzke

Small Satellite Conference

WEBERSAT, a 27 pound LEO satellite launched by the Ariane 40 on January 21, 1990 into a 500 mile polar orbit, carries several payload experiments that were developed as a learning experience for engineering students at Weber State University. The experiments include a modified color CCD camera and video flash digitizer. Operational command and control of the spacecraft and its payloads is performed by students in the College of Applied Science & Technology, from a ground station located on the WSU campus. Here, the students and their advisor's monitor on-board systems, plan & execute experiments, and observe test results. This …

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Sedsat 1 Advanced Photovoltaic Power System Technology Demonstration Flight, Dennis Wingo, Cheryl Bankston, Steve Tesney, Namsoo Kim, Ronald Gale Aug 1991

Sedsat 1 Advanced Photovoltaic Power System Technology Demonstration Flight, Dennis Wingo, Cheryl Bankston, Steve Tesney, Namsoo Kim, Ronald Gale

Small Satellite Conference

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.

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Yaw Control - A Simple Way To Enhance Solar Array Performance, Emery Reeves Aug 1991

Yaw Control - A Simple Way To Enhance Solar Array Performance, Emery Reeves

Small Satellite Conference

Solar cell arrays are used on substantially all earth orbiting spacecraft to produce electric power. Solar arrays are of three geometric types: planar, cylindrical, and omnidirectional oriented planar arrays have a geometric efficiency (ratio of solar energy capture area to total array area) of one and are used on most large spacecraft. Cylindrical arrays which have a geometric efficiency of l/π are common on spinners while most small spacecraft including those that are earth pointed use omnidirectional arrays which have a geometric efficiency of only 1/4. An earth oriented spacecraft with a body fixed planar array can achieve a geometric …

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Common-Pressure-Vessel Nickel-Hydrogen Battery Development, Burton Otzinger, James Wheeler Aug 1991

Common-Pressure-Vessel Nickel-Hydrogen Battery Development, Burton Otzinger, James Wheeler

Small Satellite Conference

The dual-cell, common-pressure vessel, nickel-hydrogen configuration has recently emerged as an option for small satellite nickel-hydrogen battery application. An important incentive is that the dual-cell, CPV configured battery presents a 30 percent reduction in volume and nearly 50 percent reduction in mounting footprint, when compared with an equivalent battery of individual pressure- vessel (IPV) cells. In addition energy density and cost benefits are significant. Eagle-Picher Industries and Rockwell International have collaborated on the development and test evaluation of a 40 Ampere-hour, nickel-hydrogen, dual-cell, CPV battery module. The module was committed to a cycle life test in Rockwell's advanced battery test …

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Miniaturized, Low-Power Parallel Processor For Space Applications, W.J. Jacobi, N.J. Teneketges, L.A. Wadsworth Aug 1991

Miniaturized, Low-Power Parallel Processor For Space Applications, W.J. Jacobi, N.J. Teneketges, L.A. Wadsworth

Small Satellite Conference

A miniaturized, low-power parallel processor for space applications is under development by Space Computer Corporation for DARPA's Advanced Space Technology Program. The basic goal of this project is the reduction, by an order of magnitude or more, of on-board processor weight, size and power consumption for space-based sensor systems. Our approach for achieving this goal is to use low power VLSI devices which maximize throughput per watt, together with three dimensional hybrid wafer-scale integration and packaging technology. In its prototype version, a l2-node processor will have a peak throughput greater than 1.2 GFLOPS and occupy a volume less than 15 …

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Leostar: A Small Spacecraft For Leo Communication Missions, G. Barresi, G. Rondinelli, C. Soddu, D. Brown Aug 1991

Leostar: A Small Spacecraft For Leo Communication Missions, G. Barresi, G. Rondinelli, C. Soddu, D. Brown

Small Satellite Conference

This paper outlines the major features of LEOSTAR, a small spacecraft able to support two way data message communications and position reporting missions with a multisatellite constellation. LEOSTAR is a three-axis gravity gradient stabilized satellite. A semi-passive control concept is envisaged with an extensible boom providing attitude stabilization together with three orthogonal Magnetic Torquers, an on-board dedicated computer and other devices. Thrusters provide the station keeping and transfer maneuvers according to an optimized strategy. A bipropellant system with monomethyhl hydrazine as propellant and nitrogen tetroxide as oxidizer is adopted. Large autonomy is envisaged through the adoption of an onboard system …

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The Dsi Small Satellite Launcher, Donald Gibbons, Jeff Wise Aug 1991

The Dsi Small Satellite Launcher, Donald Gibbons, Jeff Wise

Small Satellite Conference

Three DSI Launchers were used aboard the Discovery (STS-39) in May 1991 as part of the Infrared Background Signature Survey (IBSS). Each launcher successfully deployed a Chemical Release Observation (CRO) Sub satellite which were launched under the Complex Autonomous Payload (CAP) program, an outgrowth of NASA Goddard's GAS program. Because the CRO subsatellites contained hazardous liquids (MMH, UDMH, and MON-lO) and were launched from GAS Cylinders without lids, the launchers were required to pass NASA Shuttle Payload safety and verification requirements. Some of the more interesting components of the design were the V-band retention and separation mechanism, the separation springs …

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"Space Eggs" - Satellite Coverage Model For Low Earth Orbit Constellations, Janis Indrikis, Robert Cleave Aug 1991

"Space Eggs" - Satellite Coverage Model For Low Earth Orbit Constellations, Janis Indrikis, Robert Cleave

Small Satellite Conference

The effectiveness calculations of global, regional, and area coverage for proliferated small satellite constellations in low altitude orbits stress the capability of conventional analytical techniques. A new approach that combines the Mollweide (equal area) projection with an on-screen color manipulation of the picture elements (or pixels) has been developed and utilized over the past decade. This technique enables the optimization of large satellite constellations with multiple communication or sensor viewing configurations, with a minimum number of calculations. Complex viewing geometries are well adapted with this analytical approach, along with exclusion requirements such as the sun, moon or earth avoidance. This …

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Small Upper Stage: An Orbit Enabling Hydrazine Propulsion Stage For The Small Satellite Community, Thane Reitan, Charles Merk Aug 1991

Small Upper Stage: An Orbit Enabling Hydrazine Propulsion Stage For The Small Satellite Community, Thane Reitan, Charles Merk

Small Satellite Conference

Under funding from the Naval Research Laboratory (NRL), Rocket Research Company (RRC) has recently completed a one-year study and design effort on the Small Upper Stage (SUS). The goal of this effort was to create a generic, low-cost propulsion stage design capable of being integrated to several different launch vehicles (LV's) and capable of providing a mission enabling orbit transfer function to a variety of different small satellite missions. In order to accomplish this goal, a launch vehicle survey was conducted to establish the current LV capability and environments with respect to small satellites. In addition, a small satellite survey …

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Multi-Purpose Satellite Bus, Daniel Sakoda, Brij Agrawal Aug 1991

Multi-Purpose Satellite Bus, Daniel Sakoda, Brij Agrawal

Small Satellite Conference

This paper presents design considerations of a Multi-Purpose Satellite bus (MPS). The project was sponsored by the NASA Universities Space Research Association (USRA) Advanced Design Program. A multi-purpose satellite bus was selected as the study topic from a Statement-of-Work generated by the Defense Advanced Research Projects Agency. The estimated beginning-of-life weight of the MPS bus is 150 kg. A detailed analysis with two dissimilar payloads (a meteorological payload and a communication payload), both having a three year life, demonstrates the flexibility of the bus. The MPS bus was designed to mate with the Pegasus Air Launched Vehicle and the Taurus …

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Development Of A Space Computer - A Low Risk Approach To Control And Data Processing Applications In Small Satellites, Vincent Poole Aug 1991

Development Of A Space Computer - A Low Risk Approach To Control And Data Processing Applications In Small Satellites, Vincent Poole

Small Satellite Conference

In early 1991, Honeywell delivered three RH-1 750A based flight computers to complete the AST III program in support of a Phillips Laboratory Autonomous Navigation Demonstration Satellite. The delivery was significant for the following reasons: it was the first delivery of a space qualified RH-1750A computer, the RH-1750 Multi-Chip Module (MCM) was transitioned from a research and development effort to a B-level flight part, and, design to delivery of the first flight unit was accomplished in only 16 months. The AST III program consists of several sequential efforts which will demonstrate and validate state-of-the-art spacecraft autonomy hardware and software in …

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Army Tactical Satellite Communications, Ltc Lee Veltum, Michael Freeman Aug 1991

Army Tactical Satellite Communications, Ltc Lee Veltum, Michael Freeman

Small Satellite Conference

Army tactical commanders in the future will have assured access to satellite communications systems that can be operational within 72 hours throughout the world.

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A Small, Primary Solar-Electric Propulsion Demonstration Satellite, Hans Meissinger Aug 1991

A Small, Primary Solar-Electric Propulsion Demonstration Satellite, Hans Meissinger

Small Satellite Conference

Interest in the application of primary solar-electric propulsion to high-energy Earth orbital and deep-space missions has increased in recent years because of its inherent propellant economy and the promise of greatly enhanced payload weight capacity for a given vehicle launch weight. This paper describes a small, low-cost electric propulsion demonstration satellite, capable of ascending from low altitude to geosynchronous orbit in ten months or less, using only about 1 kW of propulsive power. Based on available technology of ion thrusters and lightweight solar arrays, and using elements of current light satellite design, this mission is of timely interest as a …

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System Requirements For Satellite Video Relays Supporting Unmanned Ground Vehicles, Jeffrey Randorf Aug 1991

System Requirements For Satellite Video Relays Supporting Unmanned Ground Vehicles, Jeffrey Randorf

Small Satellite Conference

The Unmanned Ground Vehicle Joint Project Office (UGV/JPO) has identified communications and control as the single most important issue concerning unmanned ground vehicle (UGV) deployment. This paper outlines needed capabilities for potential small satellite data relays for unmanned ground vehicle operations. Satellites could offer a solution to the inherent non-line-of-sight (NLOS), wide bandwidth dilemma.

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Utilization Of The Multiple Access Communications Satellite (Macsat) In Support Of Tactical Communications, B. Steele, C. Mccormick, K. Brandt, W. Fornwalt, R. Bonometti Aug 1991

Utilization Of The Multiple Access Communications Satellite (Macsat) In Support Of Tactical Communications, B. Steele, C. Mccormick, K. Brandt, W. Fornwalt, R. Bonometti

Small Satellite Conference

Two MACSATs were launched on May 9, 1990 on a Scout launch vehicle from Vandenberg Air Force Base, California. After a short on-orbit check-out, these research and development satellites were placed into service providing operational communications support to 2d Marine Aircraft Wing units deployed to the Persian Gulf in support of Operations Desert Shield and Desert Storm. This support was provided from August 1990 until Operation Desert Storm was completed in April 1991. During this time, many lessons were learned that are directly applicable to the design and fielding of future small tactical communications satellites. This paper will highlight some …

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Applications Of Small Satellites For Defense Space Communication Systems And Technology Development: Pegasus Flight-2 And The Launch Of Microsat, R. Bonometti, E. Nicastri, T. Darone, R. Steele, W. Montag Aug 1991

Applications Of Small Satellites For Defense Space Communication Systems And Technology Development: Pegasus Flight-2 And The Launch Of Microsat, R. Bonometti, E. Nicastri, T. Darone, R. Steele, W. Montag

Small Satellite Conference

DARPA's seven Microsats were placed into orbit on the second flight of the Pegasus. The Microsat program objective is to assess the tactical utility of small, low-cost communications satellites. This paper describes the changes made to the Pegasus since its first flight, provides an overview of the Microsat demonstration program, and outlines the preliminary results of the Pegasus launch. Finally, the near-term Army and Navy demonstration plans for Microsat are discussed.

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Comet: Gateway To Commercial Space, Thomas Ajluni, James Hager Aug 1991

Comet: Gateway To Commercial Space, Thomas Ajluni, James Hager

Small Satellite Conference

The COMmercial Experiment Transporter (COMET), scheduled to begin its first mission in September of 1992, is expected to be the baseline that is used to measure the capabilities of the next generation of commercial "To Space and Back" systems. This paper provides an overview of the COMET system with emphasis on its operational capabilities. The design of the Service Module (spacecraft bus) will be highlighted and its modular design and flexible architecture will be discussed.

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Delta Launch Vehicle Accommodations For Small Satellites, K.R. Knox Aug 1991

Delta Launch Vehicle Accommodations For Small Satellites, K.R. Knox

Small Satellite Conference

The small satellite market has suffered from the lack of availability of a low-cost and responsive transport to orbit. The emergence of new small launchers is helping to satisfy this need with dedicated launches at more affordable cost. The Delta launch vehicle also offers significant benefits to the small satellite community by comanifesting several satellites on a dedicated launch. The cost effectiveness for the constellation deployment of similar satellites is evident when compared to individual launches with dedicated launchers. This study also examines the possibility of comanifesting small satellites of different sizes and masses into low Earth orbits. The comanifesting …

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A Global Enviromental Data Distribution System, Philip Walker Aug 1991

A Global Enviromental Data Distribution System, Philip Walker

Small Satellite Conference

This paper describes a global environmental data distribution system (GEDDS) which uses a single small satellite operating in a low polar orbit. The satellite collects environmental data from remotely located instrumentation platforms and distributes it to research laboratories and other interested organizations virtually anywhere in the world. A command link also allows principal investigators to control and calibrate platform instruments on a daily basis directly from their laboratory or office.

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A Survey Of Small Spacecraft In Commercial Constellations, John Hatlelid, David Sterling Aug 1991

A Survey Of Small Spacecraft In Commercial Constellations, John Hatlelid, David Sterling

Small Satellite Conference

The capabilities that can be built into small spacecraft are increasing to the point that communications and other commercial applications are now possible. Dense electronics, small satellite technology and low cost launch options for small satellites are recent developments that have provided these new opportunities for commercial uses of space. As a result of these changes, several companies are proposing constellations of small satellites for commercial applications such as communications and geolocation. This paper provides various aspects of proposed systems with commercial applications.

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System Design For Commercial Microsatellite Missions, Dino Lorenzini, Vincenzo Violi Aug 1991

System Design For Commercial Microsatellite Missions, Dino Lorenzini, Vincenzo Violi

Small Satellite Conference

This paper presents the results of a Microsat Feasibility Study conducted by Telespazio S.p.A and Interferometrics Inc. The study examined the feasibility of three possible near term space missions: (1) data collection and relay for environmental monitoring, (2) mobile messaging and digital communications, and (3) remote sensing of sulfur dioxide content in the atmosphere and detection of wild fires. The generalized system architecture consists of a network of low Earth orbit microsatellites, an array of low cost fixed and mobile User Terminals for either communications or data collection, and a Mission Control Center tailored to the specific mission. A prototype …

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Thermion: Verification Of A Thermionic Heat Pipe In Microgravity, George Powell, Frank Redd Aug 1991

Thermion: Verification Of A Thermionic Heat Pipe In Microgravity, George Powell, Frank Redd

Small Satellite Conference

The Idaho National Engineering Laboratory (lNEL) is conducting intensive research in the design and development of a small excore heat-pipe-thermionic space nuclear reactor power system (SEHPTR). The SEHPTR spacecraft will be able to supply 40 kW of power in any given orbit. Figure 1-1 shows a conceptual diagram of the SEHPTR spacecraft. The key components in this reactor are the thermionic heat pipes. The heat pipes have two major functions: first, to convert heat energy into electrical energy, and second, to radiate the excess heat to space.

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Medsat: A Small Satellite For Malaria Early Warning And Control, James Slawski, John Vesecky, Byron Wood, James Lawless Aug 1991

Medsat: A Small Satellite For Malaria Early Warning And Control, James Slawski, John Vesecky, Byron Wood, James Lawless

Small Satellite Conference

This paper presents the design for a low cost, light satellite used to aid in the control of vector-borne diseases like malaria. The 340 kg satellite contains both a synthetic aperture radar and a visual/infrared multispectral scanner for remotely sensing the region of interest. Most of the design incorporates well established technology, but innovative features include the Pegasus launch vehicle, low mass and volume SAR and VIS/IR sensors, integrated design, low power SAR operation, microprocessor power system control, and advanced data compression and storage. This paper describes the main design considerations of the project which include, the remote sensing task, …

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To The Moon From A B-52: Robotic Lunar Exploration Using The Pegasus Winged Rocket And Ballistic Lunar Capture, Edward Belbruno, Rex Ridenoure, Jaime Fernandez Aug 1991

To The Moon From A B-52: Robotic Lunar Exploration Using The Pegasus Winged Rocket And Ballistic Lunar Capture, Edward Belbruno, Rex Ridenoure, Jaime Fernandez

Small Satellite Conference

A subset of the presently-defined NASA robotic lunar exploration objectives may be achievable with a new mission architecture involving the Pegasus winged rocket, small satellites, and a new class of Earth-Moon trajectories incorporating ballistic lunar capture. Enabling this potentially low-cost method of lunar exploration - perhaps for a few tens of millions of dollars per mission - is the application of the Weak Stability Boundary Theory developed by Belbruno during 1987-89, which leads to ballistic ("maneuverless") Earth-Moon trajectories. On such a path, a spacecraft could be orbited at the Moon for little additional ∆ V (< 50 m/s for minor trajectory correction maneuvers) beyond that supplied by the Pegasus for the initial Earth departure burn, resulting in a significant propellant savings. (Additional maneuvers would then be required to establish a more useful lunar orbit.) The price for this savings is an extended trip time to the Moon of 3-5 months. This type of trajectory is presently being demonstrated for the first time by the Japanese Hiten spacecraft, using an …

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Auroral Cluster: A Space Physics Mission For Multiple, Electronically Tethered Small Satellites, J.P. Andrews, J.R. Scherrer, J.H. Waite, J.L. Burch Aug 1991

Auroral Cluster: A Space Physics Mission For Multiple, Electronically Tethered Small Satellites, J.P. Andrews, J.R. Scherrer, J.H. Waite, J.L. Burch

Small Satellite Conference

Auroral Cluster is a space physics mission that has been identified by the NASA Space Physics Strategic Implementation Study as a candidate for flight in the next decade. Auroral Cluster will employ multiple spacecraft outfitted with similar complements of science instruments allowing simultaneous multipoint plasma measurements in the Earth's auroral regions. Co-orbiting small satellites (mass < 400 kg each) that are electronically "tethered" to share distributed spacecraft systems represent an efficient approach for achieving the science goals of the Auroral Cluster mission. Multisatellite missions represent a new trend in gathering space science data and pose many new and difficult challenges for the space systems engineer. The results of an Auroral Cluster feasibility study, which discusses a variety of mission trade-offs, are presented. A discussion of the science background and mission goals is used to identify the technical drivers for the design of the multiple spacecraft system. A mission plan and some considerations for a Auroral Cluster satellite design are presented. Special consideration is given to the spacecraft subsystems that will allow the system to be operated as a network of electronically tethered interdependent small satellites. These subsystems include attitude determination, spatial separation knowledge and control, data storage, and intersatellite communication.

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Small Spacecraft Activities At Jpl, Ross Jones Aug 1991

Small Spacecraft Activities At Jpl, Ross Jones

Small Satellite Conference

This paper presents a brief technical description of some of the small spacecraft concepts prepared by JPL for various sponsors. Some of JPL's work in microspacecraft is presented. The paper contains brief technical descriptions of the following four small spacecraft conceptual designs: 1) Lunar GAS, 2) Polar Mesoscale Explorer, 3) DARPA SHF and 4) Discovery. Since 1986, JPL has studied more than 10 small spacecraft including those to be presented here.

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