Crew transfer in orbiting spacecraft
Problems of maneuverability, locomotion, and propulsion in zero gravity, and protection and support during astronaut transfer in orbiting spacecraft
ORBITAL TRANSFER↗
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Results for “SPACECRAFT ORBIT”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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PC-402 Pioneer Venus orbiter spacecraft mission operational characteristics document
The operational characteristics of the Orbiter spacecraft and its subsystems are described. In extensive detail. Description of the nominal phases, system interfaces, and the capabilities and limitations of system level performance are included along with functional and operational descriptions at the subsystem and unit level the subtleties of nominal operation as well as detailed capabilities and limitations beyond nominal performance are discussed. A command and telemetry logic flow diagram for each subsystem is included. Each diagram encountered along each command signal path into, and each telemetry signal path out of the subsystem. Normal operating modes that correspond to the performance of specific functions at the time of specific events in the mission are also discussed. Principal backup means of performing the normal Orbiter operating modes are included.
Barker, F. C.↗
Decontamination techniques for lunar orbiting spacecraft.
Decontamination techniques and sterilization environment, discussing compatibility with components and hardware of lunar orbiting spacecraft
DECONTAMINATION↗
A quasi-inertial attitude mode for orbiting spacecraft.
A method is presented for achieving quasi-inertial orientation of an orbiting spacecraft with minimal control effort. Spacecraft motion is a small-amplitude oscillation about the orbit normal with one principal axis held in the orbital plane. The nominal orientation of this axis is arbitrary, so that any spacecraft axis normal to it may be pointed arbitrarily on the celestial sphere and remain within a small neighborhood of the nominal orientation. Oscillation amplitude can be chosen to minimize control requirements for maintaining the mode and may range up to 18.8 deg depending on spacecraft inertia. The quasi-inertial mode would be an efficient means for maintaining a nominal solar orientation for NASA's Skylab configuration if the control-moment-gyros fail in the primary attitude control system. This approach, which utilizes the backup reaction thrust system, affords a substantial reduction in propellant requirements compared to that for a true solar inertial attitude hold.
Elrod, B. D.↗
Orbital Spacecraft Consumables Resupply System
This paper describes the work completed on the Orbital Spacecraft Consumables Resupply System (OSCRS) for the Johnson Space Center. The study objective was to provide a concept to NASA for supplying earth storable liquids and gases to a variety of orbiting vehicles, including Space Station, OMV and other satellites in orbits compatible with Shuttle resupply. The design is based on a cylindrical propellant tank optimized for transporting liquids in the Orbiter bay. The tank is polar mounted with the attachment fittings configured as Orbiter sill trunnions. The pressurant tanks provide support between the sill and keel fittings. Two potential spacecraft interface mechanisms were investigated. Continuing OSCRS effort will be directed toward further standardization studies, adapting the design to the Space Station Servicing Bay and investigating the possibilities of using ELV launchers.
Berry, Thomas↗
Self-contamination and environment of an orbiting spacecraft
The flux of molecules emitted by a spacecraft and subsequently reflected to its surface was investigated. The reflection occurs upon collision of the outgassed molecules with ambient molecules. Evaluation of the flux was based on a knowledge of the spacecraft outgassing rate, the spacecraft dimensions, and the orbit parameters. Condensation rates and adsorption layers on critical surfaces were calculated from the knowledge of this flux and the nature and temperature of the gas and the surface. Based on estimated and measured emission rates, calculation of these parameters was performed for a number of spacecraft. The relationships and graphs developed allow an estimate of several important parameters for an orbiting spacecraft to be made. The pressures and densities at various distances from the spacecraft, as produced by the surrounding ambient molecules and by the spacecraft's own outgassing, are presented. The pressure and density produced by the outgassing can be obtained as a function of time if the behavior of the outgassing with time is known. The number of desorbed molecules ionized by impact with ambient charged particles and the effect of the spacecraft's electric field on polarized desorbed molecules were considered.
Scialdone, J. J.↗
Survey of VLF electric fields in the magnetosphere with the polar orbiting spacecraft, 1964-45A.
VLF electric fields in magnetosphere surveyed with polar orbiting spacecraft 1964-45A may produce large amplitude plasma oscillations
ELECTRIC FIELD↗
HF and VHF communications circuits - Earth orbiting spacecraft and ground stations
HF and VHF communications circuits for Earth orbiting spacecraft and ground stations
Towey, J. M.↗
Optimization techniques applied to passive measures for in-orbit spacecraft survivability
Optimization techniques applied to passive measures for in-orbit spacecraft survivability, is a six-month study, designed to evaluate the effectiveness of the geometric programming (GP) optimization technique in determining the optimal design of a meteoroid and space debris protection system for the Space Station Core Module configuration. Geometric Programming was found to be superior to other methods in that it provided maximum protection from impact problems at the lowest weight and cost.
Mog, Robert A.↗
Spacecraft Orbit Design and Analysis (SODA), version 1.0 user's guide
The Spacecraft Orbit Design and Analysis (SODA) computer program, Version 1.0 is described. SODA is a spaceflight mission planning system which consists of five program modules integrated around a common database and user interface. SODA runs on a VAX/VMS computer with an EVANS & SUTHERLAND PS300 graphics workstation. BOEING RIM-Version 7 relational database management system performs transparent database services. In the current version three program modules produce an interactive three dimensional (3D) animation of one or more satellites in planetary orbit. Satellite visibility and sensor coverage capabilities are also provided. One module produces an interactive 3D animation of the solar system. Another module calculates cumulative satellite sensor coverage and revisit time for one or more satellites. Currently Earth, Moon, and Mars systems are supported for all modules except the solar system module.
Stallcup, Scott S.↗
Spacecraft Orbit Design and Analysis (SODA). Version 2.0: User's guide
The Spacecraft Orbit Design and Analysis (SODA) computer program, Version 2.0, is discussed. SODA is a spaceflight mission planning system that consists of six program modules integrated around a common database and user interface. SODA runs on a VAX/VMS computer with an Evans and Sutherland PS300 graphics workstation. In the current version, three program modules produce an interactive three dimensional animation of one or more satellites in planetary orbit. Satellite visibility and sensor coverage capabilities are also provided. Circular and rectangular, off nadir, fixed and scanning sensors are supported. One module produces an interactive three dimensional animation of the solar system. Another module calculates cumulative satellite sensor coverage and revisit time for one or more satellites. Currently, Earth, Moon, and Mars systems are supported for all modules except the solar system module.
Stallcup, Scott S.↗
Dual technique magnetometer experiment for the Cassini Orbiter spacecraft
The dual technique magnetometer to fly on the Cassini Saturn Orbiter Spacecraft is described. The instrument combines two separate techniques of measuring the magnetic field in space using both fluxgate and vector helium devices. In addition, the instrument can be operated in a special scalar mode which is to be used near the planet for highly accurate determination of the interior field of the planet. As well as the planetary field, the instrument will make large contributions to the scientific measurements of the planetary magnetosphere, the highly electrically conducting region of space surrounding Saturn permeated by the Saturnian field, the interaction of Saturn and the interplanetary medium and the interaction of Titan with its space environment.
Southwood, D. J.↗
The research potential of manned earth orbiting spacecraft in the field of meteorology.
Meteorological research capability of manned Earth orbiting spacecraft with refined electromagnetic sensing instrumentation
MANNED SPACECRAFT↗
The study of basic physical/biological phenomena under zero-g conditions in earth orbital spacecraft.
Basic physical/biological phenomena studied under zero-g conditions in Earth orbital spacecraft
WEIGHTLESSNESS↗
Applications of square-root information filtering and smoothing in spacecraft orbit determination
The JPL (Jet Propulsion Laboratory) Orbit Determination Software System is a set of computer programs developed for the primary purpose of determining the flight path of deep-space mission spacecraft in NASA's Planetary Program and highly elliptical orbiting spacecraft in Earth orbit. The filtering processes available within the JPL Orbit Determination Software are discussed, and several examples are presented. In particular, solutions obtained by the Square Root Information Filter (SRIF) using Bierman's Estimation Subroutine Library (ESL) are discussed and compared with the solutions obtained by the singular value decomposition (SVD) technique. It is concluded that the SRIF filtering and smoothing algorithms are efficient and numerically stable for well-conditioned systems. The use of Bierman's ESL simplifies the task of maintaining the orbit determination software by providing efficient, tested filtering tools. For solving a large well-conditioned system (rank higher than 120), SRIF is approximately four times faster than SVD; however, for solving an ill-conditioned system, SVD is recommended.
Wang, Tseng-Chan↗
The use of terrestrial test sites and aircraft flights in preparing for remote sensing from earth orbital spacecraft.
Terrestrial test sites and aircraft flights used in preparing for remote sensing from Earth orbital spacecraft
RADAR SYSTEM↗
Conceptual design of a two stage to orbit spacecraft
This project, undertaken through the Advanced Space Design Program, developed a 'Conceptual Design of a Two Stage To Orbit Spacecraft (TSTO).' The design developed utilizes a combination of air breathing and rocket propulsion systems and is fully reusable, with horizontal takeoff and landing capability. The orbiter is carried in an aerodynamically designed bay in the aft section of the booster vehicle to the staging altitude. This TSTO Spacecraft design meets the requirements of replacing the aging Space Shuttle system with a more easily maintained vehicle with more flexible mission capability.
Armiger, Scott C.↗
Sensitivity of high-accuracy Tracking and Data Relay Satellite System (TDRSS) user spacecraft orbit determination to tracking schedules
The results of a study to analyze the dependence of TDRSS user spacecraft orbit determination consistencies on varying tracking schedules are presented. In this study, the TDRS-East orbit determination results obtained utilizing Bilateration Ranging Transponder System data were evaluated. Six state parameters, three position and three velocity components and the solar radiation pressure coefficient, are estimated for TDRS-East. It is concluded that, in order to achieve high-precision orbit determination, the tracking coverage should not fall below 10 minutes every two orbits as decreasing it to every four orbits will significantly degrade the accuracy; present state-of-the-art consistency in orbit determination using TDRSS tracking is approximately 15 to 20 meters.
Doll, C. E.↗