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Control of the ST7 Disturbance Reduction System Flight Experiment

AIP Conference Proceedings 2006年第1期873卷 529-538页

作者： P. G. Maghami O. C. Hsu J. R. O’Donnell, Jr. *Mission Engineering and Systems Analysis Division NASA Goddard Space Flight Center Greenbelt MD 20771

The Space Technology 7 (ST7) experiment will perform an on‐orbit system‐level validation of two specific Disturbance Reduction System technologies: colloidal micronewton thrusters and drag‐free control. The ST7 Disturbance Reduction System (DRS) is designed to maintain the spacecraft’s position with respect to a free‐floating test mass while limiting the residual accelerations of that test mass over the frequency range of 1 to 30 mHz. This paper presents the overall design and analysis of the spacecraft drag‐free and attitude controllers, with particular attention given to its primary mission mode. These controllers close the loop between the drag‐free sensors and the colloidal micronewton thrusters.

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The GPS space service volume

The GPS space service volume

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Institute of Navigation - 19th International Technical Meeting of the Satellite division, ION GNSS 2006

作者： Bauer, F.H. Moreau, M.C. Dahle-Melsaether, M.E. Petrofski, W.P. Stanton, B.J. Thomason, S. Harris, G.A. Sena, R.P. Temple III, L. Parker NASA Goddard Space Flight Center SI International Inc. HQ Air Force Space Command Aerospace Corporation Mission Engineering and Systems Analysis Division NASA's Goddard Space Flight Center Greenbelt MD SI International Inc. Command Control Communications and Navigation Division Headquarters Air Force Space Command Colorado Springs Systems Engineering and Integration Directorate Aerospace Corporation El Segundo CA Flight Dynamics Analysis Branch NASA's Goddard Space Flight Center ION Council Aerospace Corporation El Segundo CA Aerospace Corporation Washington DC

Prior to the advent of artificial satellites, the concept of navigating in space and the desire to understand and validate the laws of planetary and satellite motion dates back centuries. At the initiation of orbital flight in 1957, space navigation was dominated by inertial and ground-based tracking methods, underpinned by the laws of planetary motion. It was early in the 1980s that GPS was first explored as a system useful for refining the position, velocity, and timing (PVT) of other spacecraft equipped with GPS receivers. As a result, an entirely new GPS utility was developed beyond its original purpose of providing PVT services for land, maritime, and air applications. Spacecraft both above and below the GPS constellation now receive the GPS signals, including the signals that spill over the limb of the Earth. The use of radionavigation satellite services for space navigation in High Earth Orbits is in fact a capability unique to GPS. Support to GPS space applications is being studied and planned as an important improvement to GPS. This paper discusses the formalization of PVT services in space as part of an overall GPS improvement effort. It describes the GPS Space Service Volume (SSV) and compares it to the Terrestrial Service Volume (TSV). It also discusses SSV coverage with the current GPS constellation, coverage characteristics as a function of altitude, expected power levels, and coverage figures of merit.

关键词： Global positioning system

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Evaluation of a Shuttle Derived Vehicle (SDV) for cargo transportation

Evaluation of a Shuttle Derived Vehicle (SDV) for cargo tran...

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1st Space Exploration Conference: Continuing the Voyage of Discovery

作者： Roman, Jose M. Meacham, Stephen B. Krupp, Donald R. Threet, G.E. Best, Joel Davis, Stephan R. Crumbly, Christopher Olsen, Ronald A. Engler, Leah M. Garner, Tim Fawaz, Joseph S. NASA George C. Marshall Space Flight Center Marshall Space Flight Center AL 35812 NASA Headquarters Washington DC 20546 Morgan Research Corporation Huntsville AL 35805 United Space Alliance Huntsville AL 35806 Hernandez Engineering Incorporated MSFC AL 35812 Space Transportation Programs and Projects Office Systems Engineering and Integration Requirements Management NP22 MSFC Space Transportation Programs and Projects Office Systems Engineering and Integration NP22 MSFC Vehicle Integration and Performance Analysis EV12 MSFC Space Transportation Programs and Projects Office Advanced Concepts NP12 MSFC Mission Operations Laboratory Operations Engineering and Concept Development EO04 MSFC Exploration Systems Mission Directorate Requirements Division NASA Headquarters Space Transportation Programs and Projects Office NP01 MSFC Space Transportation Programs and Projects Office Exploration and Transportation Systems Development Office NP70 MSFC Space Shuttle Propulsion Office Systems Engineering and Integration MP71 MSFC Safety and Mission Assurance QD01 MSFC AIAA

ISBN: (纸本)1563477270

In this new era of space exploration, a host of launch vehicles are being examined for possible use in transporting cargo and crew to low Earth orbit and beyond. Launch vehicles derived from the Space Shuttle Program (SSP), known as Shuttle Derived Vehicles (SDVs), are prime candidates for heavy-lift duty because of their potential to minimize non-recurring costs and because the Shuttle can leverage off proven high-performance flight systems with established ground and flight support. To determine the merits of SDVs, a detailed evaluation was performed. This evaluation included a trade study and risk assessment of options based on performance, safety/reliability, cost, operations, and evolution. The purpose of this paper is to explain the approach, processes, and tools used to evaluate launch vehicles for heavy lift cargo transportation. The process included defining the trade space, characterizing the concepts, analyzing the systems, and scoring the options. The process also included a review by subject experts from NASA and industry to compare past and recent study data and assess the risks. A set of technical performance measures (TPMs) was generated based on the study requirements and constraints. Tools such as INTROS and POST were used to calculate performance, FIRST was used for prediction of reliability, and other software packages, both commercial and NASA-owned, were applied to study the trade space. By following a clear process and using the right tools a thorough assessment was performed. An SDV can be classified as either a side-mount vehicle (SMV) or an in-line vehicle (ILV). An SMV is a Space Shuttle where the Orbiter is replaced by a cargo carrier. An ILV is comprised of a modified Shuttle External Tank (ET) with engines mounted to the bottom and cargo mounted atop. For both families of vehicles, Solid Rocket Boosters (SRBs) are attached to the ET. The first derivate of Shuttle is defined as the vehicle with minimum changes necessary to transform the

关键词： Space shuttles

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Orbit optimization for the Geospace Electrodynamics Connections (GEC) mission

Orbit optimization for the Geospace Electrodynamics Connecti...

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Collection of Technical Papers - AIAA/AAS Astrodynamics Specialist Conference

作者： Mesarch, Michael A. NASA Goddard Space Flight Center Greenbelt MD 20771 Mission Engineering and Systems Analysis Division Code 595

ISBN: (纸本)1563477149

Part of NASA's Solar Terrestrial Probe line of missions, the Geospace Electrodynamics Connections (GEC) mission will deploy a formation of three spacecraft to perform in-situ atmospheric research in the low Ionosphere-Thermosphere region. These spacecraft will fly together in a "string-of-pearls" formation with variable separations ranging from 10 seconds to one-quarter of an orbit at perigee. Over the course of its two-year mission, the three spacecraft will perform ten, 1-week dipping campaigns whereby they maneuver to lower their perigee to near 134 km. Using available launch vehicle performance data, an optimal parking orbit of 222 × 1525 km was found to maximize the dry mass available while providing enough propellant to perform the ten deep-dipping campaigns over its two-year mission. The results were used to create multi-variable contour plots containing the orbit perigee, the orbit apogee, spacecraft dry mass, propellant mass, and T500 (a science data collection figure of merit that tabulates the cumulative time spent below 500 km). These plots illustrate how the mission can trade off science return relative to the cost in dry mass and propellant. Other optimal solutions such as minimum propellant or maximum T500 were found to either limit the science data collection or to be dry mass limiting, respectively. Sensitivity analyses were performed to find new optimal (maximum dry mass) solutions if the number of campaigns changed, if the coefficient of drag (CD) were different, and if the propellant specific impulse were increased. A surprising result showed that the dry mass and T500 were both increased if the number of campaigns decreased. Changes in CD provided the expected results - raising CD lowered both the dry mass and T500 while lowering CD raised both the dry mass and T500. Increases in the propellant specific impulse had the expected outcome of raising the dry mass and lowering the propellant load but there was no change in the T500 figure of merit. T

关键词： Electrodynamics

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Mode transitions for the ST7 Disturbance Reduction System experiment

Mode transitions for the ST7 Disturbance Reduction System ex...

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Collection of Technical Papers - AIAA Guidance, Navigation, and Control Conference

作者： Hsu, O.C. Maghami, P.G. Markley, F.L. O'Donnell Jr., J.R. NASA Goddard Space Flight Center Mission Engineering and Systems Analysis Division Greenbelt MD 20771 Flight Dynamics Analysis Branch Code 595 Guidance Navigation and Control Systems Engineering Branch Code 591

ISBN: (纸本)1563476703

The Space Technology 7 Disturbance Reduction System experiment will perform an on-orbit system-level validation of two technologies: a gravitational reference sensor employing a free-floating test mass and a set of colloidal micronewton thrusters. The Disturbance Reduction System is designed to maintain the spacecraft's position with respect to a free-floating test mass to less than 10 nm/√Hz over the frequency range of 1 to 30 m Hz. This paper presents the modes that compose the Disturbance Reduction System spacecraft control as well as the strategy used to transition between modes. A high-fidelity model of the system, which incorporates rigid-body models of the spacecraft and two test masses (18 degrees of freedom), is developed and used to evaluate the performance of each mode and the efficacy of the transition strategy.

关键词： Control equipment

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GSFC information systems technology developments supporting the vision for space exploration

GSFC information systems technology developments supporting ...

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A Collection of Technical Papers - AIAA Space 2004 Conference and Exposition

作者： Hughes, Peter Dennehy, Cornelius Mosier, Gary Smith, Dan Dallas, Lisa NASA Goddard Space Flight Center Greenbelt MD 20771 Mail Code 502 AETD Mission Engineering and Systems Analysis Division Mail Code 590 James Webb Space Telescope Project Systems Engineering Services and Advanced Concepts Branch Mail Code 592 Systems Integration and Engineering Branch Mail Code 581 Advanced Automation and Architectures Branch Mail Code 588

ISBN: (纸本)1563477203

The Vision for Space Exploration will guide NASA's future human and robotic space activities. The broad range of human and robotic missions now being planned will require the development of new system-level capabilities enabled by emerging new technologies. Goddard Space Flight Center is actively supporting the Vision for Space Exploration in a number of program management, engineering and technology areas. This paper provides a brief background on the Vision for Space Exploration and a general overview of potential key Goddard contributions. In particular, this paper focuses on describing relevant GSFC information systems capabilities in architecture development;interoperable command, control and communications;and other applied information systems technology/research activities that are applicable to support the Vision for Space Exploration goals. Current GSFC development efforts and task activities are presented together with future plans.

关键词： Space research

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Decentralized control of satellite clusters under limited communication

Decentralized control of satellite clusters under limited co...

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Collection of Technical Papers - AIAA Guidance, Navigation, and Control Conference

作者： Belanger, Gene M. Ananyev, Slava Speyer, Jason L. Chichka, David F. Carpenter, J. Russell University of California Los Angeles Los Angeles CA 90095 George Washington University Washington DC 20052 NASA Goddard Space Flight Center Greenbelt MD 20771 Mechanical and Aerospace Engineering Department University of California Los Angeles Box 951597 48-121 Engineering IV Los Angeles CA 90095-1597 Aerospace Corporation MS M4-971 2350 E. El Segundo Blvd. El Segundo CA 90245 Mechanical and Aerospace Engineering Department University of California Los Angeles Box 951597 38-137 Engineering IV Los Angeles CA 90095-1597 Mechanical and Aerospace Engineering Department George Washington University 801 22nd Street NW Washington DC 20052 Mission Engineering Systems Analysis Division Flight Dynamics Analysis Branch NASA Goddard Space Flight Center Greenbelt MD 20771

ISBN: (纸本)1563476703

Two decentralized control algorithms - each employing a unique information exchange scheme - are considered. One of these algorithms employs a communication paradigm in which control and local state estimate information is exchanged between members of a formation after any one of the members executes a control. The other algorithm requires only that control information be exchanged between members;this is thought to be the least information exchange that can sustain an affine control law. The objective of this paper is to evaluate the performance of these algorithms when applied to a satellite formation control problem. To this end, the algorithms are applied in the context of a nonlinear satellite cluster simulation, where Earth oblateness effects and measurement uncertainties are taken into account. The cluster is required to achieve a specified formation at a defined point on an elliptic reference orbit. Simulation results are obtained for several different orbits and compared to a baseline case involving a centralized controller design.

关键词： Decentralized control

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Navigation accuracy guidelines for orbital formation flying

Navigation accuracy guidelines for orbital formation flying

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AIAA Guidance, Navigation, and Control Conference and Exhibit 2003

作者： Carpenter, J. Russell Alfriend, Kyle T. Flight Dynamics Analysis Branch Mission Engineering and Systems Analysis Division NASA Goddard Space Flight Center Greenbelt MD 20771 United States Aerospace Engineering Dept Texas A and M University College Station TX 77843 United States

ISBN: (纸本)9781624100901

Some simple guidelines based on the accuracy in determining a satellite formation's semi-major axis differences are useful in making preliminary assessments of the navigation accuracy needed to support such missions. These guidelines are valid for any elliptical orbit, regardless of eccentricity. Although maneuvers required for formation establishment, reconfiguration, and station-keeping require accurate prediction of the state estimate to the maneuver time, and hence are directly affected by errors in all the orbital elements, experience has shown that determination of orbit plane orientation and orbit shape to acceptable levels is less challenging than the determination of orbital period or semi-major axis. Furthermore, any differences among the member's semi-major axes are undesirable for a satellite formation, since it will lead to differential along-track drift due to period differences. Since inevitable navigation errors prevent these differences from ever being zero, one may use the guidelines this paper presents to determine how much drift will result from a given relative navigation accuracy, or conversely what navigation accuracy is required to limit drift to a given rate. Since the guidelines do not account for non-two-body perturbations, they may be viewed as useful preliminary design tools, rather than as the basis for mission navigation requirements, which should be based on detailed analysis of the mission configuration, including all relevant sources of uncertainty.

关键词： Navigation

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The effect of sensor failure on the attitude and rate estimation of the map spacecraft

The effect of sensor failure on the attitude and rate estima...

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AIAA Guidance, Navigation, and Control Conference and Exhibit 2003

作者： Bar-Itzhack, Itzhack Y. Harman, Richard R. Technion-Israel Institute of Technology Haifa 32000 Israel Flight Dynamics Analysis Branch Code 595 Mission Engineering and Systems Analysis Division NASA-Goddard Space Flight Center Greenbelt MD 20771 United States

ISBN: (纸本)9781624100901

This work describes two algorithms for computing the angular rate and attitude in case of a gyro and a Star Tracker failure in the Microwave Anisotropy Probe (MAP) satellite, which was placed in the L2 parking point from where it collects data to determine the origin of the universe. The nature of the problem is described, two algorithms are suggested, an observability study is carried out and real MAP data are used to determine the merit of the algorithms. It is shown that one of the algorithms yields a good estimate of the rates but not of the attitude whereas the other algorithm yields a good estimate of the rate as well as two of the three attitude angles. The estimation of the third angle depends on the initial state estimate. There is a contradiction between this result and the outcome of the observability analysis. An explanation of this contradiction is given in the paper. Although this work treats a particular spacecraft, its conclusions are more general.

关键词： Observability

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Flight reconstruction of the mars pathfinder Disk-Gap-Band parachute drag coefficient

Flight reconstruction of the mars pathfinder Disk-Gap-Band p...

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17th AIAA Aerodynamic Decelerator systems Technology Conference and Seminar 2003

作者： Desai, Prasun N. Schofield, John T. Lisano, Michael E. Aerospace Systems Concepts and Analysis Competency NASA Langley Research Center Hampton VA 23681 United States Earth and Space Sciences Division Jet Propulsion Laboratory California Institute of Technology Pasadena CA 91109 United States Mission Analysis Software Engineering Group Jet Propulsion Laboratory California Institute of Technology Pasadena CA 91109 United States

ISBN: (纸本)9781624100871

On July 4, 1997, the Mars Pathfinder (MPF) mission successfully landed on Mars. The entry, descent, and landing (EDL) scenario employed the use of a Disk-Gap-Band parachute design to decelerate the Lander. Flight reconstruction of the entry using MPF flight accelerometer data revealed that the MPF parachute decelerated faster than predicted. In the summer of 2003, the Mars Exploration Rover (MER) mission will send two Landers to the surface of Mars arriving in January 2004. The MER mission utilizes a similar EDL scenario and parachute design as that employed by MPF. As a result, characterizing the degree of underperformance of the MPF parachute system is critical for the MER EDL trajectory design. This paper provides an overview of the methodology utilized to estimate the MPF parachute drag coefficient as experienced on Mars.

关键词： Parachutes

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