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At least 1,333 records · Page 74
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Space Operations Center System Analysis: Requirements for a Space Operations Center, revision A

The system and program requirements for a space operations center as defined by systems analysis studies are presented as a guide for future study and systems definition. Topics covered include general requirements for safety, maintainability, and reliability, service and habitat modules, the health maintenance facility; logistics modules; the docking tunnel; and subsystem requirements (structures, electrical power, environmental control/life support; extravehicular activity; data management; communications and tracking; docking/berthing; flight control/propulsion; and crew support). Facilities for flight support, construction, satellite and mission servicing, and fluid storage are included as well as general purpose support equipment.

Woodcock, G. R.↗
NASA NTRS1982

Advanced Multipurpose Rendezvous Tracking System Study

Rendezvous and docking (R&D) sensors needed to support Earth orbital operations of vehicles were investigated to determine the form they should take. An R&D sensor must enable an interceptor vehicle to determine both the relative position and the relative attitude of a target vehicle. Relative position determination is fairly straightforward and places few constraints on the sensor. Relative attitude determination, however, is more difficult. The attitude is calculated based on relative position measurements of several reflectors placed in a known arrangement on the target vehicle. The constraints imposed on the sensor by the attitude determination method are severe. Narrow beamwidth, wide field of view (fov), high range accuracy, and fast random scan capability are all required to determine attitude by this method. A consideration of these constraints as well as others imposed by expected operating conditions and the available technology led to the conclusion that the sensor should be a cw optical radar employing a semiconductor laser transmitter and an image dissector receiver.

Laurie, R. J.↗
NASA NTRS1982

Lessons learned - Americans in space

Milestones in the learning process during development of spaceflight capability for different NASA missions are traced from the initial launch of the Mercury escape rocket to the advent of the Shuttle. A detached heat shield on the first manned Mercury orbital flight led to a decision for reentry with retrorockets attached, a situation which demonstrated a need for on-line communications with the spacecraft construction engineers. The Gemini program served to develop EVA techniques and docking procedures essential for the Apollo missions. Apollo 8 circled the moon after only one manned test flight of the equipment due to the success of the first flight. Lunar landing simulation training exposed the astronauts to situations beyond the human ability to respond. The training was justified when computer overload required the pilot to retake manual control of some spacecraft functions during the successful first lunar landing. All lessons previously learned were used to safely return the damaged Apollo 13 to earth. The Skylab missions provided an opportunity to maintain rotating teams of flight controllers on a 24-hr/day basis for periods of months. Finally, the six-year hiatus of U.S. manned space activities between the end of the Skylab missions and the first Shuttle flight provided time for incorporating previous lessons into new procedures, training strategies, and data resources.

Kranz, E.↗
NASA NTRS1982

Satellite Services Workshop, Volume 1

Key issues associated with the orbital servicing of satellites are examined including servicing spacecraft and equipment, servicing operations, economics, satellite design, docking and berthing, and fluid management.

Source record↗
NASA NTRS1982

Berthing/docking

Three studies were completed establishing sensor performance, technology status, and conceptual design requirements for rendezvous stationkeeping, and docking. A consideration of design constraints and the availale technology has led to the conclusion that the sensor should be a CW optical radar employing a semiconductor-laser transmitter and an image-dissector receiver. The performance obtainable for a representative sensor was compared to specifications generated during the study and it was found that this type of sensor can meet the needs of future Earth-orbital operations.

Erwin, H.↗
NASA NTRS1982

Spacecraft automatic umbilical system

A conceptual definition of an appropriate berthing technique and a prototype design of an automatic umbilical system suitable for use with payloads carried by the Space Shuttle are presented. A four-element berthing system is described. This concept consists of a set of four remote manipulator system (RMS)-type end-effector capture/tie-down devices on the power system and corresponding RMS-type grapple fittings on the payload. In operation, the RMS maneuvers the payload to a position where the four grapple fittings can be snared within the end-effectors and then secured to the power system. The concept takes advantage of mechanisms and operating techniques developed for attaching the RMS to a payload. Although the umbilical installation is attached to the docking interface structure, its operation is independent and it must comply with a set of primary requirements specified by Marshall Space Flight Center (MSFC), which is presented.

Rudy, G. C.↗
NASA NTRS1982

Characteristics of the handling and positioning aid

The handling and positioning aid which (HPA) provides a wide range of adjustable work stations both inboard and outboard of the cargo bay is discussed. It can assist with berthing and docking, it is robust, stiff, has a simple control system, and is modular. An articulated arm version of HPA employed in a typical servicing mission is shown. Mounted on a base frame that spans the Orbiter cargo bay, the 6 m arm is long enough to hold the satellite being serviced and keep its solar array clear of the Orbiter radiators. By adjusting the length and angle of the support platform mast, and rotating the tip of the HPA arm, almost every item on the satellite can be reached. Spares and change-out units can be brought to and from the work site by the RMS, which is controlled from the aft flight deck. The fore and aft position of the base frame can be changed between Orbiter flights and this, together with the 5 degrees of freedom (DOF) of the long arm, allows work sites to be chosen that meet the clearance, reach and vision requirements of many missions. Flight article activities are shown are shown above the dashed horizontal line and Development Test Article (DTA) work below. Flight article requirements and concepts and the design of the DTA are developed.

Goodwin, C. J.↗
NASA NTRS1981

Feasibility study of the solar scientific instruments for Spacelab/Orbiter

The feasibility and economics of mounting and operating a set of solar scientific instruments in the backup Skylab Apollo Telescope Mount (ATM) hardware was evaluated. The instruments used as the study test payload and integrated into the ATM were: the Solar EUV Telescope/Spectrometer; the Solar Active Region Observing Telescope; and the Lyman Alpha White Light Coronagraph. The backup ATM hardware consists of a central cruciform structure, called the "SPAR', a "Sun End Canister' and a "Multiple Docking Adapter End Canister'. Basically, the ATM hardware and software provides a structural interface for the instruments; a closely controlled thermal environment; and a very accurate attitude and pointing control capability. The hardware is an identical set to the hardware that flow on Skylab.

Leritz, J.↗
NASA NTRS1981

Some characteristics and advantages of LANDSAT 3 return beam vidicon images

One advantage of a LANDSAT 3 return beam vidicon (RBV) scene is the synoptic view it provides. A 1:500,000 paper print of the size 19.4 cm x 19.4 cm encompasses an area of about 3,721 square miles (9,637 sq. km.) and this compares very favorably in coverage to small scale aerial photography. A second important advantage is that the ground resolution is 38 by 38 meters. Compared to the resolution of the MSS which is 79 by 79 meters the RBV provides a wealth of detail useful for many purposes. A great variety of man made structures are visible including bridges, roads, docks, and small airfields. Agricultural field patterns are clear and settlements of various sizes can be identified and delineated. A third advantage is related to the approximate panchromatic spectral response displayed in RBV images. Since many aerial photographic interpreters are accustomed to working with panchromatic photographs, they should have no difficulty understanding and putting RBV images immediately into use.

Baker, S.↗
NASA NTRS1982

Comet composition and density analyzer

Distinctions between cometary material and other extraterrestrial materials (meteorite suites and stratospherically-captured cosmic dust) are addressed. The technique of X-ray fluorescence (XRF) for analysis of elemental composition is involved. Concomitant with these investigations, the problem of collecting representative samples of comet dust (for rendezvous missions) was solved, and several related techniques such as mineralogic analysis (X-ray diffraction), direct analysis of the nucleus without docking (electron macroprobe), dust flux rate measurement, and test sample preparation were evaluated. An explicit experiment concept based upon X-ray fluorescence analysis of biased and unbiased sample collections was scoped and proposed for a future rendezvous mission with a short-period comet.

Clark, B. C.↗
NASA NTRS1983

Structural Dynamics and Control of Large Space Structures, 1982

Basic research in the control of large space structures is discussed. Active damping and control of flexible beams, active stabilization of flexible antenna feed towers, spacecraft docking, and robust pointing control of large space platform payloads are among the topics discussed.

Brumfield, M. L.↗
NASA NTRS1983

Tethered satellite control mechanism

The tethered satellite control mechanisms consist of four major subsystems. The reel drive mechanism stores the tether. It is motor driven and includes a level wind to uniformly feed the tether to the reel. The lower boom mechanism serves two primary functions: (1) it measures tether length and velocity as the tether runs through the mechanism, and (2) it reads the tether tension at the reel. It also provides change the direction for the tether from the reel to the upper boom mechanism. The deployment boom positions the upper boom mechanism with satellite out of the cargo bay. The deployment function places the 500-kg satellite 20 m away from the Space Shuttle (producing a small natural gravity gradient force), impacts an initial velocity to the satellite for deployment, and allows for satellite docking at a safe distance from the body of the Space Shuttle. The upper boom mechanism (UBM) services three functions: (1) it provides tether control to the satellite as the satellite swings in and out of plane; (2) it reads tether tension in the low range during the early deployment and final retrieval parts of the mission; and (3) it produces additional tether tension at the reel when tether tension to the satellite is in the low range.

Kyrias, G. M.↗
NASA NTRS1983

Development of deployable structures for large space platform systems. Volume 1: Executive summary

Candidate deployable linear platform system concepts suitable for development to technology readiness by 1986 are reviewed. The systems concepts were based on trades of alternate deployable/retractable structure concepts, integration of utilities, and interface approaches for docking and assembly of payloads and subsystems. The deployable volume studies involved generation of concepts for deployable volumes which could be used as unpressurized or pressurized hangars, habitats and interconnecting tunnels. Concept generation emphasized using flexible materials and deployable truss structure technology.

Cox, R. L.↗
NASA NTRS1983

Definition of technology development missions for early space station, orbit transfer vehicle servicing. Volume 1: Executive summary

Orbital Transfer Vehicle (OTV) servicing study scope, propellant transfer, storage and reliquefaction technology development missions (TDM), docking and berthing TDM, maintenance TDM, OTV/payload integration TDM, combined TDMS design, summary space station accomodations, programmatic analysis, and TDM equipment operational usage are discussed.

Source record↗
NASA NTRS1983

Control - Demands mushroom as station grows

The NASA space station, which is presently in the planning stage, is to be composed of both rigid and nonrigid modules, rotating elements, and flexible appendages subjected to environmental disturbances from the earth's atmospheric gravity gradient, and magnetic field, as well as solar radiation and self-generated disturbances. Control functions, which will originally include attitude control, docking and berthing control, and system monitoring and management, will with evolving mission objectives come to encompass such control functions as articulation control, autonomous navigation, space traffic control, and large space structure control. Attention is given to the advancements in modular, distributed, and adaptive control methods, as well as system identification and hardware fault tolerance techniques, which will be required.

Szirmay, S. Z.↗
NASA NTRS1983

Structures and mechanisms - Streamlining for fuel economy

The design of prospective NASA space station components which inherently possess the means for structural growth without compromising initial system characteristics is considered. In structural design terms, space station growth can be achieved by increasing design safety factors, introducing dynamic isolators to prevent loads from reaching the initial components, or preplanning the refurbishment of the original structure with stronger elements. Design tradeoffs will be based on the definition of on-orbit loads, including docking and maneuvering, whose derived load spectra will allow the estimation of fatigue life. Improvements must be made in structural materials selection in order to reduce contamination, slow degradation, and extend the life of coatings. To minimize on-orbit maintenance, long service life lubrication systems with advanced sealing devices must be developed.

Card, M. F.↗