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An MSC/NASTRAN finite element model of the higher harmonic control configured OH-6A helicopter fuselage was developed. This finite element model was verified by performing various model checkouts and correlation with results from a ground vibration test.
A general overview is given of the operations, engineering challenges, and components of the Hubble Space Telescope. Deployment, checkout and servicing in space are discussed. The optical telescope assembly, focal plane scientific instruments, wide field/planetary camera, faint object spectrograph, faint object camera, Goddard high resolution spectrograph, high speed photometer, fine guidance sensors, second generation technology, and support systems and services are reviewed.
A discussion of modeling plan objectives, followed by a description of the AH-64A aircraft including all general features, major components, and primary and structure definitions are presented. Following the aircraft description, a discussion of the modeling guidelines and model checkout procedure are provided. The NASTRAN finite element analysis is set up to be suitable to predict both static internal loads and vibrations. Finally, the results, schedule, and planned versus actual manhours for this work are presented.
As the NASA center responsible for assembly, checkout, servicing, launch, recovery, and operational support of Space Transportation System elements and payloads, Kennedy Space Center (KSC) is placing increasing emphasis on KSC's research and technology program. In addition to strengthening those areas of engineering and operations technology that contribute to safer, more efficient, and more economical execution of the current mission, the technological tools needed to execute KSC's mission relative to future programs are being developed. The Engineering Development Directorate encompasses most of the laboratories and other KSC resources that are key elements of research and technology program implementation and is responsible for implementation of the majority of the projects in this KSC 1990 annual report. Projects under the following topics are covered: (1) materials science; (2) hazardous emissions and contamination monitoring; (3) biosciences; (4) autonomous systems; (5) communications and control; (6) meteorology; (7) technology utilization; and (8) mechanics, structures, and cryogenics.
A safe haven and work supported PV power systems on the lunar surface will likely be required by NASA in support of the manned outpost scheduled for the post-2000 lunar/Mars exploration and colonization initiative. Initial system modeling and computer analysis shows that the concept is workable and contains no major high risk technology issues which cannot be resolved in the circa 2000 to 2025 timeframe. A specific selection of the best suited type of electric thruster has not been done; the initial modeling was done using an ion thruster, but Rocketdyne must also evaluate arc and resisto-jets before a final design can be formulated. As a general observation, it appears that such a system can deliver itself to the Moon using many system elements that must be transported as dead payload mass in more conventional delivery modes. It further appears that a larger power system providing a much higher safe haven power level is feasible if this delivery system is implemented, perhaps even sufficient to permit resource prospecting and/or lab experimentation. The concept permits growth and can be expanded to include cargo transport such as habitat and working modules. In short, the combined payload could be manned soon after landing and checkout. NASA has expended substantial resources in the development of electric propulsion concepts and hardware that can be applied to a lunar transport system such as described herein. In short, the paper may represent a viable mission on which previous investments play an invaluable role. A more comprehensive technical paper which embodies second generation analysis and system size will be prepared for near-term presentation.
It is demonstrated here that complete checkout of a basic substructure can be done under the special circumstance of a sliding connection with offsets. Stiff bar connectors make this possible so long as the bar coordinates are aligned with the displacement coordinates at the sliding surface.
Progress in assessing the feasibility, benefits, and risks associated with AI expert systems applied to low cost expendable launch vehicle systems is described. Part one identified potential application areas in vehicle operations and on-board functions, assessed measures of cost benefit, and identified key technologies to aid in the implementation of decision support systems in this environment. Part two of the program began the development of prototypes to demonstrate real-time vehicle checkout with controller and diagnostic/analysis intelligent systems and to gather true measures of cost savings vs. conventional software, verification and validation requirements, and maintainability improvement. The main objective of the expert advanced development projects was to provide a robust intelligent system for control/analysis that must be performed within a specified real-time window in order to meet the demands of the given application. The efforts to develop the two prototypes are described. Prime emphasis was on a controller expert system to show real-time performance in a cryogenic propellant loading application and safety validation implementation of this system experimentally, using commercial-off-the-shelf software tools and object oriented programming techniques. This smart ground support equipment prototype is based in C with imbedded expert system rules written in the CLIPS protocol. The relational database, ORACLE, provides non-real-time data support. The second demonstration develops the vehicle/ground intelligent automation concept, from phase one, to show cooperation between multiple expert systems. This automated test conductor (ATC) prototype utilizes a knowledge-bus approach for intelligent information processing by use of virtual sensors and blackboards to solve complex problems. It incorporates distributed processing of real-time data and object-oriented techniques for command, configuration control, and auto-code generation.
ROSAT was designed specifically to detect high energy radiation, by using its telescopes to study x ray and ultraviolet emissions, regions of the electromagnetic spectrum that cannot be seen and that cannot penetrate the Earth's atmosphere. ROSAT is an international astronomical observatory project. ROSAT's science mission is divided into two phases. With its in-orbit checkout period complete, ROSAT has begun phase one of its mission, an all sky survey to map the heavens. When the 6 month mapping survey is complete, the satellite will begin phase two and be pointed at selected objects, studying individual targets, for the remainder of its mission.
The National Transonic Facility (NTF) was operational in a combined checkout and test mode for about 3 years. During this time there were many challenges associated with movement of mechanical components, operation of instrumentation systems, and drying of insulation in the cryogenic environment. Most of these challenges were met to date along with completion of a basic flow calibration and aerodynamic tests of a number of configurations. Some of the major challenges resulting from cryogenic environment are reviewed with regard to hardware systems and data quality. Reynolds number effects on several configurations are also discussed.
The Retrievable Payload Carrier (RPC) is described which is a multi-experiment, free-flyer spacecraft being privately developed to make in-space experimentation more accessible and economically feasible for research and development organizations. The carrier concept was derived from NASA's highly successful and flight proven Long Duration Exposure Facility (LDEF). The LDEF capabilities were enhanced to meet new customer requirements. This reusable payload carrier is planned for launch and retrieval by the space shuttle on a regular basis. The RPC's compact design facilitates flexible manifesting of the shuttle cargo bay space, thereby, permitting timely launches and retrievals. The vehicle is designed so that either the entire carrier can be retrieved from orbit, or individual experiment pallets can be removed and replaced in orbit. This gives customers even greater control over their experiment recoveries. A fully operational RPC System consists of: (1) a carrier spacecraft; (2) a ground control station for communication with customer payloads and the carrier; (3) a ground processing facility to provide refurbishment, final checkout, and integration of customer payloads and the carrier; and (4) the personnel required to support both the development and operation phases of the program. Customer payloads will fly 6 to 18 month missions, or longer, as required. Spreading launch, operations, and retrieval costs over multiple experimental payloads results in minimized customer costs. The RPC Program's initial objective is to operate a simple carrier system which meets basic customer service needs.
The topics covered include the following: (1) space basing technology requirements sources; (2) orbit transfer vehicle (OTV) processing heritage; (3) ground processing progression to space processing; (4) technology requirements for space based OTV servicing and maintenance; (5) design and development schedule for OTV's and OTV accommodations/ support hardware; (6) cryogenic technology test program development; (7) cryogenic propellant transfer, storage, and reliquefaction management summary; (8) propellant transfer technology analysis and ground testing; (8) OTV propellant storage depot development critical scaling relationships; (9) flight experiment options; (10) OTV maintenance; (11) automated fault detection/ isolation and system checkout summary; (12) engine replacement; (13) alternative docking operation; (14) OTV/payload integration; and (15) technology criticality and capability assessment. This document is presented in viewgraph form.
The topics covered include the following: (1) space basing agenda; (2) mission scenario 4E-5B, crew and Lunar Excursion Vehicle (LEV) delivery; (3) final concept candidate, crew concept 4E-2B; (4) space transfer vehicle (STV) concept 4E-5B; (5) configuration summary for crew concept 4E-5B; (6) configuration definition for crew concept 4E-5B; (7) low earth orbit node assembly and checkout operations; (8) criteria for operation objectives; (9) LTV and STV main engines; (10) Space Station Freedom impacts; (11) aerobrakes; and (12) on orbit operations. This document is presented in viewgraph form.
This paper describes the Magellan spacecraft designed to collect information from the surface of Venus while orbiting this planet. Special attention is given to the attitude and articulation control of the spacecraft; the command, data, and data storage; the thermal control; and instrumentation. The operations at Venus, which will include Venus orbit insertion and in-orbit checkout and to both routine and nonroutine (at a period when Venus will be in superior conjunction, and the solar plasma will drive Magellan's telecommunications signal-to-noise ratio to a very high value) mapping of the surface, are discussed. Also discussed are operations on earth, carried out by the new Space Flight Operations Control Center.
The Space Exploration Initiative program and the Space Transfer Vehicle studies provide the opportunity to evaluate the engine requirements for the next generation space engine within the context of a credible but technologically demanding program. Some of these requirements are generic, basically independent of the architecture, and others are mission and configuration dependent. Generic requirements include high reliability, space-basing, man-rataing, long life and reusability, and extended health monitoring, including automatic pre-mission checkout. Mission and configuration dependent requirements include vehicle/engine interfaces, engine throttling, performance specifications, engine system architecture, and operational requirements. It is argued that engine technology requirements must be extended from the usual performance-related issues to encompass reliability, space-basing, life, and extended health monitoring.
The Magellan spacecraft arrived at Venus on August 10, 1990 to begin global high-resolution radar image and altimeter mapping and gravity field determination of the planet. Mapping of this cloud covered planet is done from an elliptical orbit with a 3.15 hour period and a 275 km periapsis. After the initial checkout of the spacecraft, the primary missions lasts for 243 days (one Venus day); the time it takes for Venus to make one revolution beneath the spacecraft. The data collected by Magellan is expected to provide an understanding of the geological and geophysical nature of the planet Venus, and the general processes that control planetary evolution.
During 1991, the software developed allowed an operator to configure and checkout the TSI, Inc. laser velocimeter (LV) system prior to a run. This setup procedure established the operating conditions for the TSI MI-990 multichannel interface and the RMR-1989 rotating machinery resolver. In addition to initializing the instruments, the software package provides a means of specifying LV calibration constants, controlling the sampling process, and identifying the test parameters.
Over 11 hours of three-axis microgravity accelerometer data were successfully measured in the payload bay of Space Shuttle Columbia as part of the Microgravity Disturbances Experiment on STS-32. These data were measured using the High Resolution Accelerometer Package and the Aerodynamic Coefficient Identification Package which were mounted on the Orbiter keel in the aft payload bay. Data were recorded during specific mission events such as Orbiter quiescent periods, crew exercise on the treadmill, and numerous Orbiter engine burns. Orbiter background levels were measured in the 10(exp -5) G range, treadmill operations in the 10(exp -3) G range, and the Orbiter engine burns in the 10(exp -2) G range. Induced acceleration levels resulting from the SYNCOM satellite deploy were in the 10 (exp -2) G range, and operations during the pre-entry Flight Control System checkout were in the 10(exp -2) to 10(exp -1) G range.
The primary objective of the METSAT project is to provide a satellite system that meets the National Environmental Satellite Data and Information Service (NESDIS) requirements as specified by NOAA. For the GOES I-M spacecraft, these requirements include an imager and sounder system, a data collection system, and a search and rescue system. The Space Transportation System and GOES I-M development philosophy and the satellite transfer orbit philosophy are explained. The spacecraft will be launched from the Kennedy Space Center using Atlas G/Centaur D-1A expendable launch vehicles. The coverage required for launch and the support of transfer and drift orbits will consist of the 26-m antenna as prime and the TBD antenna as backup for 11 days at all complexes. There will be contingency support 15 days for on-station spacecraft checkout. After the initial 30 to 45 days, the Deep Space Network (DSN) is committed for emergency support. Contingency and emergency support will be provided by Goldstone only. Information is given in tabular form for DSN support, frequency assignments, telemetry, command, and tracking support responsibility.