Space-flight mission design for flight and crew safety.
Manned space flight safety through mission trajectory design, considering hardware, software and operational constraints
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Manned space flight safety through mission trajectory design, considering hardware, software and operational constraints
DSIF telemetry and command processing operational program for providing software to Mariner Mars 1971 mission
The Apollo Program experience from early 1962 to July 1969 with respect to the engineering-simulation support and the problems encountered is summarized in this report. Engineering simulation in support of the Apollo guidance and control system is discussed in terms of design analysis and verification, certification of hardware in closed-loop operation, verification of hardware/software compatibility, and verification of both software and procedures for each mission. The magnitude, time, and cost of the engineering simulations are described with respect to hardware availability, NASA and contractor facilities (for verification of the command module, the lunar module, and the primary guidance, navigation, and control system), and scheduling and planning considerations. Recommendations are made regarding implementation of similar, large-scale simulations for future programs.
A review of the guidance, navigation and control projects in support of the space shuttle program was conducted. The subjects considered include the following: (1) functional and performance requirements, (2) mission requirements, (3) operating systems software definition, (4) orbit navigation using various sensors, (5) fault detection, isolation and recovery, and (6) passive rendezvous sensors requirements definition.
Activities of the Goddard Space Flight Center are described in the areas of planets and interplanetary media, comets, astronomy and high-energy physics, solar physics, atmospheres, terrestrial physics, ocean science, sensors and space technology, techniques, user space data systems, space communications and navigation, and system and software engineering. Flight projects and mission definition studies are presented, and institutional technology is described.
The control of deep mission spacecraft by computing and signaling to the spacecraft a series of propulsive, velocity correction commands which maneuver the craft to its desired course is examined. The technical elements of the global navigation system (measurement, communications, computation, and propulsion) are described. The ground-computing facilities used to navigate spacecraft on deep space missions consist of computer and software systems used to compute orbits from radio tracking and on-board optical image data (radio, Doppler, and VLBI measurements). The accuracy of these measurements is evaluated, and the modeling of the data is discussed. Examples concerned with the navigation of Voyager and Galileo are presented.
NASA's Mission Control Center, located at Johnson Space Center, is incrementally moving from a centralized architecture to a distributed architecture. Starting with STS-29, some host-driven console screens will be replaced with graphics terminals driven by workstations. These workstations will be supplied realtime data first by the Real Time Data System (RTDS), a system developed inhouse, and then months later (in parallel with RTDS) by interim and subsequently operational versions of the Mission Control Center Upgrade (MCCU) software package. The Real Time Interactive Display Environment (RTIDE) was built by Space Shuttle flight controllers to support the rapid development of multiple new displays to support Shuttle flights. RTIDE is a display building tool that allows non-programmers to define object-oriented, event-driven, mouseable displays. Particular emphasis was placed on upward compatibility between RTIDE versions, ability to acquire data from different data sources, realtime performance, ability to modularly upgrade RTIDE, machine portability, and a clean, powerful user interface. The operational and organizational factors that drove RTIDE to its present form, the actual design itself, simulation and flight performance, and lessons learned in the process are discussed.
The 1991 Research and Technology Report for Goddard Space Flight Center is presented. Research covered areas such as (1) earth sciences including upper atmosphere, lower atmosphere, oceans, hydrology, and global studies; (2) space sciences including solar studies, planetary studies, Astro-1, gamma ray investigations, and astrophysics; (3) flight projects; (4) engineering including robotics, mechanical engineering, electronics, imaging and optics, thermal and cryogenic studies, and balloons; and (5) ground systems, networks, and communications including data and networks, TDRSS, mission planning and scheduling, and software development and test.
This paper describes the Payload Deployment and Retrieval System (PDRS) Failure Analysis and Diagnosis problem, our planned use of an expert system employing the C Language Integrated Production System (CLIPS) language to solve it, and our progress to date. In addition, it will address the importance of the overall design within the context of automation in the RTDS architecture, the methodology used, and the validation approach taken. The Decision Support System will evolve as a modularized rule-based system programmed in the CLIPS expert system language. Each of five modules represents a subsystem of the RMS and includes the positioning and retention hardware (MPM/MRL), the Display & Control panel (D8C), the Arm Based Electronics (ABE), the End Effector (EE), and the Orbiter to RMS data interface unit (MCIU). The MPM/MRL subsystem was chosen as the target of a prototype development and its knowledge base is completed. Testing and validation of the software is conducted by experienced mission controllers. The initial design stages for the D&C panel module are beginning.
With the threat of damage to aerospace systems (space station, shuttle, hypersonic a/c, solar power satellites, loss of life, etc.) from collision with debris (manmade/artificial), there exists an opportunity for the design of a novel system (collision avoidance) to be incorporated into the overall design. While incorporating techniques from ccd and remote sensing technologies, an integrated system utilized in the infrared/visible spectrum for detection, tracking, localization, and maneuvering from doppler shift measurements is achievable. Other analysis such as impact assessment, station keeping, chemical, and optical tracking/fire control solutions are possible through this system. Utilizing modified field programmable gated arrays (software reconfiguring the hardware) the mission and mission effectiveness can be varied. This paper outlines the theoretical operation of a prototype system as it applies to collision avoidance (to be followed up by research).
The 1993 Research and Technology Report for Goddard Space Flight Center is presented. Research covered areas such as (1) flight projects; (2) space sciences including cosmology, high energy, stars and galaxies, and the solar system; (3) earth sciences including process modeling, hydrology/cryology, atmospheres, biosphere, and solid earth; (4) networks, planning, and information systems including support for mission operations, data distribution, advanced software and systems engineering, and planning/scheduling; and (5) engineering and materials including spacecraft systems, material and testing, optics and photonics and robotics.
This thesis presents documentation for the Advanced Application Flight Experiment (AAFE) pulse compression radar altimeter and its role in the NASA Multisensor Airborne Altimetry Experiment over Greenland in 1993. The AAFE Altimeter is a Ku-band microwave radar which has demonstrated 14 centimeter range precision in operation over arctic ice. Recent repairs and improvements were required to make the Greenland missions possible. Transmitter, receiver and software modifications, as well as the integration of a GPS receiver are thoroughly documented. Procedures for installation, and operation of the radar are described. Finally, suggestions are made for further system improvements.
For the past five years, the Flight Dynamics Division (FDD) at NASA's Goddard Space Flight Center has been carrying out a detailed domain analysis effort and is now beginning to implement Generalized Support Software (GSS) based on this analysis. GSS is part of the larger Flight Dynamics Distributed System (FDDS), and is designed to run under the FDDS User Interface / Executive (UIX). The FDD is transitioning from a mainframe based environment to systems running on engineering workstations. The GSS will be a library of highly reusable components that may be configured within the standard FDDS architecture to quickly produce low-cost satellite ground support systems. The estimates for the first release is that this library will contain approximately 200,000 lines of code. The main driver for developing generalized software is development cost and schedule improvement. The goal is to ultimately have at least 80 percent of all software required for a spacecraft mission (within the domain supported by the GSS) to be configured from the generalized components.
Xontech, Inc.'s software package, XonVu, simulates the missions of Voyager 1 at Jupiter and Saturn, Voyager 2 at Jupiter, Saturn, Uranus and Neptune, and Giotto in close encounter with Comet Halley. With the program, the user can generate scenes of the planets, moons, stars or Halley's nucleus and tail as seen by Giotto, all graphically reproduced with high accuracy in wireframe representation. Program can be used on a wide range of computers, including PCs. User friendly and interactive, with many options, XonVu can be used by a space novice or a professional astronomer. With a companion user's manual, it sells for $79.
The Multiple Autonomous Discrete Event Controllers for Constellations (MADECC) project is an effort within the National Aeronautics and Space Administration Goddard Space Flight Center's (NASA/GSFC) Information Systems Division to develop autonomous positioning and attitude control for constellation satellites. It will be accomplished using traditional control theory and advanced coordination algorithms developed by the Johns Hopkins University Applied Physics Laboratory (JHU/APL). This capability will be demonstrated in the discrete event control test-bed located at JHU/APL. This project will be modeled for the Leonardo constellation mission, but is intended to be adaptable to any constellation mission. To develop a common software architecture. the controllers will only model very high-level responses. For instance, after determining that a maneuver must be made. the MADECC system will output B (Delta)V (velocity change) value. Lower level systems must then decide which thrusters to fire and for how long to achieve that (Delta)V.
Brahms is a multi-agent modeling and simulation language and distributed runtime system developed at NASA. It can be used to model and run a simualtion of the distributed work activities of multiple agents, such as humans,robots, and software agents, to coordinate a mission on one or more locations.Brahms is being used to model activities at the Flashline Man Arctic Research Station for possible use in planning Mars missions. The station is located at Haughton Crater, Devon Island, Nutiavut, Arctic Canada.
High reliability of mission- and safety-critical software systems has been identified by NASA as a high-priority technology challenge. We present an approach for the performance analysis of a neural network (NN) in an advanced adaptive control system. This problem is important in the context of safety-critical applications that require certification, such as flight software in aircraft. We have developed a tool to measure the performance of the NN during operation by calculating a confidence interval (error bar) around the NN's output. Our tool can be used during pre-deployment verification as well as monitoring the network performance during operation. The tool has been implemented in Simulink and simulation results on a F-15 aircraft are presented.
Desert RATS (Research and Technology Studies) is a combined group of inter-NASA center scientists and engineers, collaborating with representatives of industry and academia, for the purpose of conducting remote field exercises. These exercises provide the capability to validate experimental hardware and software, to evaluate and develop mission operational techniques, and to identify and establish technical requirements applicable for future planetary exploration. D-RATS completed its ninth year of field testing in September 2006. Dry run test activities prior to testing at designated remote field site locations are initially conducted at the Johnson Space Center (JSC) Remote Field Demonstration Test Site. This is a multi-acre external test site located at JSC and has detailed representative terrain features simulating both Lunar and Mars surface characteristics. The majority of the remote field tests have been subsequently conducted in various high desert areas adjacent to Flagstaff, Arizona. Both the local JSC and remote field test sites have terrain conditions that are representative of both the Moon and Mars, such as strewn rock and volcanic ash fields, meteorite crater ejecta blankets, rolling plains, hills, gullies, slopes, and outcrops. Flagstaff is the preferred remote test site location for many reasons. First, there are nine potential test sites with representative terrain features within a 75-mile radius. Second, Flagstaff is the location of the United States Geologic Survey (USGS)/Astrogeology Branch, which historically supported Apollo astronaut geologic training and currently supports and provides host accommodations to the D-RATS team. Finally, in considering the importance of logistics in regard to providing the necessary level of support capabilities, the Flagstaff area provides substantial logistics support and lodging accommodations to take care of team members during long hours of field operations.