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NASA NTRS2002

Technology Requirements for Information Management

This report provides the results of a panel study conducted into the technology requirements for information management in support of application domains of particular government interest, including digital libraries, mission operations, and scientific research. The panel concluded that it was desirable to have a coordinated program of R&D that pursues a science of information management focused on an environment typified by applications of government interest - highly distributed with very large amounts of data and a high degree of heterogeneity of sources, data, and users.

Graves, Sara↗
NASA NTRS2003

Automated Reasoning CICT Program/Intelligent Systems Project ATAC-PRT Review

An overview is presented of the Automated Reasoning CICT Program/Intelligent Systems project. Automated reasoning technology will help NASA missions by increasing the amount of science achieved, ensuring safety of spacecraft and surface explorers, and by enabling more robust mission operations.

Morris, Robert↗
NASA NTRS2003

WMAP Observatory Thermal Design and On-Orbit Thermal Performance

The Wilkinson Microwave Anisotropy Probe (WMAP) observatory, launched June 30, 2001, is designed to measure the cosmic microwave background radiation with unprecedented precision and accuracy while orbiting the second Lagrange point (L2). The instrument cold stage must be cooled passively to <95K, and systematic thermal variations in selected instrument components controlled to less than 0.5 mK (rms) per spin period. This paper describes the thermal design and testing of the WMAP spacecraft and instrument. Flight thermal data for key spacecraft and instrument components are presented from launch through the first year of mission operations. Effects of solar flux variation due to the Earth's elliptical orbit about the sun, surface thermo-optical property degradations, and solar flares on instrument thermal stability are discussed.

Glazer, Stuart D.↗
NASA NTRS2003

Plasma Interactions with a Negative Biased Electrodynamic Tether

The ProSEDS conductive tether design incorporates two distinct types of tethers from a plasma interaction viewpoint. The 200 m closest to the Delta 11 spacecraft is insulated from the plasma, and the remaining 5000 m is semi-bare. This latter portion is semi-bare because it has a conductive coating applied to the wires to permit electron collection while also regulating the overall tether temperature. Because the tether possesses these two distinct types of tethers, a transition point exists between the two types that form a triple point with the space plasma. Insulated tethers can suffer from a second plasma interaction if the insulation is weakened or breached, such as by pinholes caused by small particle debris strikes. Because electrodynamic tethers are typically long, they have a high probability of such impacts. These impacting particles may not be of sufficient size to severe the tether, but they can easily be of sufficient size to damage the tether insulation. Samples of both the ProSEDS tether transition region and the insulated tether section (with various degrees of pinhole damage) were placed into the MSFC plasma chamber and biased to typical ProSEDS open circuit tether potentials (-500 V to -1600 V). The results of the testing showed that the transition region of the tether (i.e. the triple point) arced and burned the tether in two at -900 V, and the damaged insulated sections arced and burned in two between -1000 V and -1600, depending on the pinhole damage geometry. tether design and make the tether ready for flight. To reduce the pinhole arcing risk, ProSEDS mission operations were changed to eliminate the negative potential on the tether. The results of the testing campaign and the design changes implemented to ensure a successful flight will be described.

Vaughn, Jason A.↗
NASA NTRS1990

The Genesis Solar Wind Sample Return Mission

The Genesis spacecraft was launched on August 8 from Cape Canaveral on a journey to become the first spacecraft to return from interplanetary space. The fifth in NASA's line of low-cost Discovery-class missions, its goal is to collect samples of solar wind and return them to Earth for detailed isotopic and elemental analysis. The spacecraft is to collect solar wind for over two years, while circling the L1 point 1.5 million km sunward of the earth, before heading back for a capsule-style re-entry in September, 2004. After parachute deployment, a mid-air helicopter recovery will be used to avoid a hard landing. The mission has been in the planning stages for over ten years. Its cost, including development, mission operations, and sample analysis, is approximately $209M. The Genesis science team, headed by principal investigator Donald Burnett of Caltech, consists of approximately 20 co-investigators from universities and science centers around the country and internationally. The spacecraft consists of a relatively flat spacecraft bus containing most of the subsystem components, situated below a sample return capsule (SRC) which holds the solar-wind collection substrates and an electrostatic solar wind concentrator. Some of the collectors are exposed throughout the collection period, for a sample of bulk solar wind, while others are exposed only to certain solar wind regimes, or types of flow. Ion and electron spectrometers feed raw data to the spacecraft control and data-handling (C&DH) unit, which determines ion moments and electron flux geometries in real time. An algorithm is used to robotically decide between interstream (IS), coronal hole (CH), and coronal mass ejection (CME) regimes, and to control deployment of the proper arrays to sample these wind regimes independently. This is the first time such a solar-wind decision algorithm has been used on board a spacecraft.

Wiens, Roger C.↗
NASA NTRS2003

An Internet Protocol-Based Software System for Real-Time, Closed-Loop, Multi-Spacecraft Mission Simulation Applications

The paper will provide an overview of the web-based distributed simulation software system developed for end-to-end, multi-spacecraft mission design, analysis, and test at the NASA Goddard Space Flight Center (GSFC). This software system was developed for an internal research and development (IR&D) activity at GSFC called the Distributed Space Systems (DSS) Distributed Synthesis Environment (DSE). The long-term goal of the DSS-DSE is to integrate existing GSFC stand-alone test beds, models, and simulation systems to create a "hands on", end-to-end simulation environment for mission design, trade studies and simulations. The short-term goal of the DSE was therefore to develop the system architecture, and then to prototype the core software simulation capability based on a distributed computing approach, with demonstrations of some key capabilities by the end of Fiscal Year 2002 (FY02). To achieve the DSS-DSE IR&D objective, the team adopted a reference model and mission upon which FY02 capabilities were developed. The software was prototyped according to the reference model, and demonstrations were conducted for the reference mission to validate interfaces, concepts, etc. The reference model, illustrated in Fig. 1, included both space and ground elements, with functional capabilities such as spacecraft dynamics and control, science data collection, space-to-space and space-to-ground communications, mission operations, science operations, and data processing, archival and distribution addressed.

Davis, George↗
NASA NTRS2003

Science Goal Driven Automation for NASA Missions: The Science Goal Monitor

Infusion of automation technologies into NASA s future missions will be essential not only to achieve substantial reduction in mission operations staff and costs, but also in order to both effectively handle an exponentially increasing volume of scientific data and to successfully meet dynamic, opportunistic scientific goals and objectives. Current spacecraft operations cannot respond to science driven events, such as intrinsically variable or short-lived phenomena in a timely manner. For such investigations, we must teach our platforms to dynamically understand, recognize, and react to the scientists goals. While much effort has gone into automating routine spacecraft operations to reduce human workload and hence costs, applying intelligent automation to the science side, i.e., science data acquisition, data analysis and reactions to that data analysis in a timely and still scientifically valid manner, has been relatively under-emphasized.

Korathkar, Anuradha↗
NASA NTRS2004

Improved Mars Upper Atmosphere Climatology

The detailed characterization of the Mars upper atmosphere is important for future Mars aerobraking activities. Solar cycle, seasonal, and dust trends (climate) as well as planetary wave activity (weather) are crucial to quantify in order to improve our ability to reasonably depict the state of the Mars upper atmosphere over time. To date, our best information is found in the Mars Global Surveyor (MGS) Accelerometer (ACC) database collected during Phase 1 (Ls = 184 - 300; F10.7 = 70 - 90) and Phase 2 (Ls = 30 - 90; F10.7 = 90 - 150) of aerobraking. This database (100 - 170 km) consists of thermospheric densities, temperatures, and scale heights, providing our best constraints for exercising the coupled Mars General Circulation Model (MGCM) and the Mars Thermospheric General Circulation Model (MTGCM). The Planetary Data System (PDS) contains level 0 and 2 MGS Accelerometer data, corresponding to atmospheric densities along the orbit track. Level 3 products (densities, temperatures, and scale heights at constant altitudes) are also available in the PDS. These datasets provide the primary model constraints for the new MGCM-MTGCM simulations summarized in this report. Our strategy for improving the characterization of the Mars upper atmospheres using these models has been three-fold : (a) to conduct data-model comparisons using the latest MGS data covering limited climatic and weather conditions at Mars, (b) to upgrade the 15-micron cooling and near-IR heating rates in the MGCM and MTGCM codes for ad- dressing climatic variations (solar cycle and seasonal) important in linking the lower and upper atmospheres (including migrating tides), and (c) to exercise the detailed coupled MGCM and MTGCM codes to capture and diagnose the planetary wave (migrating plus non-migrating tidal) features throughout the Mars year. Products from this new suite of MGCM-MTGCM coupled simulations are being used to improve our predictions of the structure of the Mars upper atmosphere for the upcoming MRO aerobraking exercises in 2006. A Michigan website, containing MTGCM output fields from previous climate simulations, is being expanded to include new MGCM-MTGCM simulations addressing planetary wave influences upon thermospheric aerobraking fields (densities and temperatures). In addition, similar MTGCM output fields have been supplied to the MSFC MARSGRAM - 200X empirical model, which will be used in mission operations for conducting aerobraking maneuvers.

Bougher, S. W.↗
NASA NTRS2004

Case Study of Risk Mitigation Based on Hardware/Software Integration (HSI) Testing for the International Space Station (ISS) Node 2 Module

Within the pressurized elements of the International Space Station (ISS), requirements exist to ensure a safe, habitable environment for the crew. In order to provide this environment, thermal control components work in conjunction with software controls to provide heat rejection for subsystem avionics equipment, for the environmental control system and for experiment payloads. It is essential to ISS operations, mission success and crew safety that necessary testing incorporates the extreme conditions to ensure proper performance. This paper provides a general description and methodology applied to thermal related Hardware/Software Integration (HSI) tests for the ISS Node 2 module. A detailed test plan was developed and implemented with two objectives: the first was for risk mitigation of the thermal control algorithms and software qualification, and the second was for data collection which will substantiate thermalhydraulic models of the Internal Active Thermal Control System (IATCS). Analytical models are utilized to determine on-orbit performance for conditions and scenarios where the simulation of actual on-orbit system performance is limited by test configuration constraints. Node 2 IATCS HSI activities were performed at the Alenia Spazio facility in Torino, Italy with participation from the National Aeronautics and Space Administration (NASA), Alenia Spazio, Jacobs Engineering Sverdrup (JE Sverdrup) and Boeing.

Holt, James Mike↗
NASA NTRS2003

Planetary Protection for Polar Mars Missions

The picture of Mars that is emerging from the Mars Global Surveyor and Odyssey results contrasts markedly from that portrayed shortly after the Viking missions ended. Particularly intriguing is the abundance of water ice seen both in the polar caps themselves, and in lower latitudes outside of the polar regions. Along with the new data comes a heightened consideration of the potential for biological contamination that may be carried by future missions, and its possible effects. Particularly challenging are scenarios where missions carrying perennial heat sources of high capacity and longevity (e.g., Radioisotope Thermoelectric Generators) could, by non-nominal landings or other mission operations be introduced to close contact with water ice on Mars - potentially forming Earthlike environments that could accommodate the growth of contaminant organisms.

Rummel, J. D.↗
NASA NTRS2004

Plasma Interactions With a Negative Biased Electrodynamic Tether

The ProSEDS conductive tether design incorporates two distinct types of tethers from a plasma interaction viewpoint. The 200 m closest to the Delta II spacecraft is insulated from the plasma, and the remaining 4800 m is semi-bare. This latter portion is considered semi-bare because a conductive coating, which is designed to collect electrons from the plasma, was applied to the wires to regulate the overall tether temperature. Because the tether has both insulating and conductive tether sections, a transition point exists between the two that forms a triple point with the space plasma. Also, insulated tethers can arc to the space plasma if the insulation is weakened or breached by pinholes caused by either improper handling or small meteoroid and orbital debris strikes. Because electrodynamic tethers are typically long, they have a high probability of these impacts. The particles, which strike the tether, may not have sufficient size to severe the tether, but they can easily penetrate the tether insulation producing a plasma discharge to the ambient plasma. Samples of both the ProSEDS tether transition region and the insulated tether section with various size of pinholes were placed into the MSFC plasma chamber and biased to typical ProSEDS open circuit tether potentials (-500 V to -1600 V). The results of the testing showed that the transition region of the tether (i.e. the triple point) arced to the ambient plasma at -900 V, and the tethers damaged by a pinhole or simulated debris strike arced to the plasma between -700 V and -900 V. Specific design steps were taken to eliminate the triple point issue in the ProSEDS tether design and make it ready for flight. To reduce the pinhole arcing risk, ProSEDS mission operations were changed to eliminate the high negative potential on the insulated tether. The results of the testing campaign and the design changes implemented to ensure a successful flight are described.

Vaughn, Jason A.↗
NASA NTRS2004

Mission Success for Combustion Science

This presentation describes how mission success for combustion experiments has been obtained in previous spaceflight experiments and how it will be obtained for future International Space Station (ISS) experiments. The fluids and combustion facility is a payload planned for the ISS. It is composed of two racks: the fluids Integrated rack and the Combustion INtegrated Rack (CIR). Requirements for the CIR were obtained from a set of combustion basis experiments that served as surrogates for later experiments. The process for experiments that fly on the ISS includes proposal selection, requirements and success criteria definition, science and engineering reviews, mission operations, and postflight operations. By following this process, the microgravity combustion science program has attained success in 41 out of 42 experiments.

Weiland, Karen J.↗
NASA NTRS2004

Swift Gamma-Ray Burst Explorer: Mission Design for Rapid, Accurate Location of Gamma-ray Bursts

The Swift Gamma-ray Burst Explorer is a NASA Mid-sized Explorer (MIDEX) with the primary mission of determining the origins of Gamma-Ray Bursts (GRBs). It will be the first mission to autonomously respond to newly-discovered GRBs and provide immediate follow-up narrow field instruments capable of multi-wavelength (UV, Optical, X-ray) observations. The characteristics of GRBs that are the key mission design drivers, are their non-repeating and brief duration bursts of multi-wavelength photons. In addition, rapid notification of the location and characteristics of the GRBs to ground-and-space- based observatories drive the end-to-end data analysis and distribution requirements. The Swift mission is managed by the GSFC, and includes an international team of contributors that each bring their unique perspective that have proven invaluable to the mission. The spacecraft bus, provided by Spectrum Astro, Inc. was procured through a Rapid Spacecraft Development Office (RSDO) contract by the GSFC. There are three instruments: the Burst Alert Telescope (BAT) provided by the GSFC; the X-Ray Telescope (XRT) provided by a team led by the Pennsylvania State University (PSU); and the Ultra-Violet Optical Telescope (UVOT), again managed by PSU. The Mission Operations Center (MOC) was developed by and is located at PSU. Science archiving and data analysis centers are located at the GSFC, in the UK and in Italy.

Bundas, David J.↗
NASA NTRS2005

A Proven Ground System Architecture for Promoting Collaboration and Common Solutions at NASA

NASA Goddard Space Flight Center's "GMSEC" ground system architecture was presented at GSAW2003 as a concept being studied. GMSEC would utilize a publish/subscribe middleware framework and standardized interfaces to allow custom and COTS ground system components to plug-and-play. This capability, in turn, would reduce integration costs, allow for technology infusion over time, and encourage the development and sharing of common components across missions and organizations. At GSAW2004, GMSEC was presented at a breakout session as a system working well in the NASA lab and being applied as an integral piece of reengineering efforts for several GSFC missions. Today, GMSEC is supporting five satellites at GSFC and has been selected by several future missions. Over 30 plug-and-play components are now available to missions using the GMSEC approach. Other organizations, including Marshall Space Flight Center, Johns Hopkins University's Applied Physic Lab, and the Institute for Scientific Research are each developing GMSEC-compatible components. Based on the success of GMSEC and efforts at other NASA Centers, the message bus approach is now being evaluated as a NASA Agency-wide approach for many future missions involving multiple NASA Centers as we move towards the goals of NASA s new Exploration Initiative. The presentation will explain the basic technical concepts of using a publish/subscribe framework for mission operations support (and its applicability to flight systems as well). Lessons learned on NASA's GMSEC program will allow the audience to better understand the significant benefits of this architecture approach over the traditional "one-off" solution approach. The point of the presentation is to show the long-term benefits of using a ground system architecture which incorporates many of the successful GMSEC concepts - message bus, mix of COTS and custom software, standard interfaces, plug-and-play, etc. The implications for the development process will also be discussed.

Smith, Danford↗
NASA NTRS2005

Shuttle-Derived Launch Vehicles' Capablities: An Overview

Shuttle-Derived Launch Vehicle (SDLV) concepts have been developed by a collaborative team comprising the Johnson Space Center, Marshall Space Flight Center, Kennedy Space Center, ATK-Thiokol, Lockheed Martin Space Systems Company, The Boeing Company, and United Space Alliance. The purpose of this study was to provide timely information on a full spectrum of low-risk, cost-effective options for STS-Derived Launch Vehicle concepts to support the definition of crew and cargo launch requirements for the Space Exploration Vision. Since the SDLV options use high-reliability hardware, existing facilities, and proven processes, they can provide relatively low-risk capabilities to launch extremely large payloads to low Earth orbit. This capability to reliably lift very large, high-dollar-value payloads could reduce mission operational risks by minimizing the number of complex on-orbit operations compared to architectures based on multiple smaller launchers. The SDLV options also offer several logical spiral development paths for larger exploration payloads. All of these development paths make practical and cost-effective use of existing Space Shuttle Program (SSP) hardware, infrastructure, and launch and flight operations systems. By utilizing these existing assets, the SDLV project could support the safe and orderly transition of the current SSP through the planned end of life in 2010. The SDLV concept definition work during 2004 focused on three main configuration alternatives: a side-mount heavy lifter (approximately 77 MT payload), an in-line medium lifter (approximately 22 MT Crew Exploration Vehicle payload), and an in-line heavy lifter (greater than 100 MT payload). This paper provides an overview of the configuration, performance capabilities, reliability estimates, concept of operations, and development plans for each of the various SDLV alternatives. While development, production, and operations costs have been estimated for each of the SDLV configuration alternatives, these proprietary data have not been included in this paper.

Rothschild, William J.↗
NASA NTRS2005

Science with Constellation-X

NASA's upcoming Constellation-X mission, one of two flagship missions in the Beyond Einstein program, will have more than 100 times the collecting area of any previous spectroscopic mission operating in the 0.25-40 keV bandpass and will enable high-throughput, high spectral resolution studies of sources ranging from the most luminous accreting supermassive black holes in the Universe to the disks around young stars where planets form. This booklet, which was assembled during early 2005 using the contributions of a large team of Astrophysicists, outlines the important scientific questions for the decade following this one and describes the areas where Constellation-X is going to have a major impact. These areas include the exploration of the space-time geometry of black holes spanning nine orders of magnitude in mass and the nature of the dark energy and dark matter which govern the expansion and ultimate fate of the Universe. Constellation-X will also explore processes referred to as "cosmic feedback" whereby mechanical energy, radiation, and chemical elements from star formation and black holes are returned to interstellar and intergalactic medium, profoundly affecting the development of structure in the Universe, and will also probe all the important life cycles of matter, from stellar and planetary birth to stellar death via supernova to stellar endpoints in the form of accreting binaries and supernova remnants.

Hornschemeier, Ann↗
NASA NTRS2005

Mixed-Initiative Planning in MAPGEN: Capabilities and Shortcomings

MAPGEN (Mixed-initiative Activity Plan GENerator) is a mixed-initiative system that employs automated constraint-based planning, scheduling, and temporal reasoning to assist the Mars Exploration Rover mission operations staff in generating the daily activity plans. This paper describes the mixed-initiative capabilities of MAPGEN, identifies shortcomings with the deployed system, and discusses ongoing work to address some of these shortcomings.

Bresina, John L.↗
NASA NTRS2005

Systems Engineering and Integration for Advanced Life Support System and HST

Systems engineering (SE) discipline has revolutionized the way engineers and managers think about solving issues related to design of complex systems: With continued development of state-of-the-art technologies, systems are becoming more complex and therefore, a systematic approach is essential to control and manage their integrated design and development. This complexity is driven from integration issues. In this case, subsystems must interact with one another in order to achieve integration objectives, and also achieve the overall system's required performance. Systems engineering process addresses these issues at multiple levels. It is a technology and management process dedicated to controlling all aspects of system life cycle to assure integration at all levels. The Advanced Integration Matrix (AIM) project serves as the systems engineering and integration function for the Human Support Technology (HST) program. AIM provides means for integrated test facilities and personnel for performance trade studies, analyses, integrated models, test results, and validated requirements of the integration of HST. The goal of AIM is to address systems-level integration issues for exploration missions. It will use an incremental systems integration approach to yield technologies, baselines for further development, and possible breakthrough concepts in the areas of technological and organizational interfaces, total information flow, system wide controls, technical synergism, mission operations protocols and procedures, and human-machine interfaces.

Kamarani, Ali K.↗

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