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Results for “Free-flyer”

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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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Propulsion-free separation and rendezvous of small Shuttle free-flyers using controlled differential drag

A natural successor in the Shuttle era to many sounding rocket flights is the free-flyer mode of operation, in which the Shuttle Orbiter releases a subsatellite (with payload), effects a desired separation, and finally approaches and retrieves the free-flyer. This paper proposes replacing, to the maximum extent feasible, the propulsive maneuvers required for the Orbiter by equivalent relative motions obtained through controlled differential drag (via changes in free-flyer effective area and/or Orbiter attitude changes). Simplified analytical techniques are developed and feasibility is verified. Several illustrative examples are specified (e.g., a 3-km separation in 1 day, with 4-day return).

King, J. C.↗
NASA NTRS1979

Propulsion-free separation and rendezvous of small shuttle free-flyers using controlled differential drag

A natural successor in the Shuttle era to many sounding rocket flights is the free-flyer mode of operation, in which the Shuttle Orbiter releases a subsatellite (with payloads), effects a desired separation, and approaches and retrieves the free-layer. The propulsive maneuvers required of the Orbiter by equivalent relative motions obtained through controlled differential drag (via changes in free-layer effective area and/or Orbiter attitude changes) are replaced. Simplified analytical techniques are developed and feasibility is verified.

King, J. C.↗
NASA NTRS1979

25-kW power module

The 25-kW power module design and operational characteristics and the benefits for payloads are presented. The module will allow the Shuttle Orbiter to be utilized on-orbit to its optimum capability of power and duration for sortie/Spacelab missions, and will provide central power-rich base for free-flyer payloads requiring increased electrical power and on-orbit stay-times of up to 5 years. Concepts of the module in the sortie and free-flyer modes are depicted with resource capabilities for experimentation in astronomy, solar physics, solar terrestrial observations, and materials processing which require long duration and/or high power missions. In the sortie mode operation the Orbiter fuel cell will be in an idle mode, with the 25-kW module providing payload power needs, and in the free-flyer mode the module will provide power needs to multiple payloads. Design considerations, the thermal control subsystem, the attitude control subsystem, command and data handling, and the electrical power subsystem are described.

Powell, L. E.↗
NASA NTRS1979

A detached experiment carrier aids adaptation of experiments from sounding rockets to Space Shuttle

The detached experiment carrier (DEC) system aids the adaptation of small, low-weight experiments to Space Shuttle missions. The carrier system consists of the detached experiment carrier (free-flyer), a command station at the Orbiter aft station, and a flight support station in the Orbiter payload bay. The carrier is a compact vehicle that is radio controlled by the Shuttle crew. It uses control television, command, and cold gas propulsion systems to deploy experiments from and later rendezvous with the Orbiter. The carrier propulsion system also maintains the attitude control required during experiment execution. Results of engineering investigation, analysis, component design and development, and testing indicate that the DEC system concept is practical. Results of preliminary engineering investigations, including maneuvering system handling qualities and television/telemetry display formats, indicate that the concept of flying the DEC 'out of' and 'into' the Orbiter payload bay is both safe and practical for small, compact free-flyer deployment and retrieval. This paper describes the carrier system, its operations, and potential applications.

Ritz, W. F.↗
NASA NTRS1974

A spacecraft integrated power/attitude control system

A study to determine the viability and application of a system capable of performing the dual function of power storage/generation and attitude control has been conducted. Results from the study indicate that an integrated power/attitude control system (IPACS) can satisfy future mission requirements while providing significant savings in weight, volume, and cost over conventional systems. A failure-mode configuration of an IPACS was applied to a shuttle-launched RAM free-flyer and simulated using make-do hardware linked to a hybrid computer. Data from the simulation runs indicate that control interactions resulting from heavy power demands have minimal effect on system control effectiveness. The system was shown to be capable of meeting the stringent pointing requirements of 1 arc-second while operating under the influence of an orbital disturbance environment and during periods of momentum variations imposed by energy transfer requirements.

Keckler, C. R.↗
NASA NTRS1975

An orbiting molecular shield vacuum facility - A materials laboratory in space

Certain classes of materials processing experiments require a combination of near zero gravity and ultrahigh vacuum. This combination of environmental requirements can be obtained within a molecular shield vacuum facility deployed from the Space Shuttle Orbiter. To avoid degradation by Orbiter effluents, it is necessary to deploy the facility from the Orbiter's immediate vicinity to a distance of about 100 meters. This may be achieved with an extendable/retractable boom, so that power and other resources are supplied by the Orbiter. Alternatively, the facility may be deployed as a free-flyer satellite and retrieved on a subsequent Orbiter mission. Preliminary results of boom design and dynamics analyses are presented.

Youngblood, J. W.↗
NASA NTRS1977

Guntersville Workshop on Solar-Terrestrial Studies

The separation of purely solar physics from magnetospheric physics, and the effects of solar activity on geomagnetic activity are investigations which can be accomplished using the shuttle orbiter in an extended sortie mode, or an unmanned solar terrestrial observatory powered by the power module in an extended duration mode. When the power module is used with the shuttle in a sortie support mode, both the instrument capacity and the time in orbit of the orbiter can be increased several fold. In the free-flyer mode, the power module would be capable of providing power, basic attitude control, basic thermal control and housekeeping communications for unmanned, large, independent mission payloads in low earth orbit for periods of 6 months or longer. Instrument requirements for interdisciplinary joint observational programs are discussed for studies of the magnetosphere, the atmosphere, sun-weather relationships. Description summary charts of the power module are included.

Source record↗
NASA NTRS1978

Next steps in space transportation and operations

Design of a 25-kW power or utilities module, capable of extending the effective duration of Spacelab missions, is discussed. The power module, planned for availability in 1984, could also support a Spacelab modified to be a free-flyer by providing attitude control and power. In addition, development of a 250-kW power module to support a Shuttle-tended space platform or a Shuttle-tended space construction base is projected. A free-flying teleoperator capable of deboosting Skylab, systems to construct large planar arrays in space, and a habitable module providing crew quarters for continuously manned operations are also described.

Disher, J. H.↗
NASA NTRS1978

An orbital service module systems concept

An Orbital Service Module (OSM) system represents a concept for an evolutionary program that will provide utilities services such as electrical power, heat rejection, attitude control, and communications to support payload operations in both Shuttle-tended and untended (free-flyer) modes. The initial program step is a Space Transportation System (STS) power extension package (a solar array system carried by the Orbiter and deployed by the remote manipulator system). The power extension package (PEP) develops the major components of the more sophisticated OSM vehicles. Major objectives of such an approach are (1) the continuous matching of a capability to meet real needs while avoiding the pitfalls usually associated with the uncertainties inherent in long-range prediction of future requirements, and (2) the economies attendant with program continuity and hardware commonality. The initial Orbiter-carried PEP and several later OSM system growth options are discussed.

Craig, J. W.↗
NASA NTRS1978

The 25 kW power module evolution study. Part 1: Payload requirements and growth scenarios

Payload power level requirements and their general impact on the baseline and growth versions of the 25 kW power module during the 1983 to 1990 period are discussed. Extended duration Orbiter sortie flight, supported by a power module, with increased payload power requirements per flight, and free-flyer payload missions are included. Other payload disciplines considered, but not emphasized for the 1983 to 1986 period include astrophysics/astronomy, earth observations, solar power satellite, and life sciences. Of these, only the solar power satellite is a prime driver for the power module.

Source record↗
NASA NTRS1979

Digital controller design: Analysis of the annular suspension pointing system

The Annular Suspension and Pointing System (ASPS) is a payload auxiliary pointing device of the Space Shuttle. The ASPS is comprised of two major subassemblies, a vernier and a coarse pointing subsystem. The experiment is attached to a mounting plate/rim combination which is suspended on magnetic bearing/actuators (MBA) strategically located about the rim. Fine pointing is achieved by gimballing the plate/rim within the MBA gaps. Control about the experiment line-of-sight is obtained through the use of a non-contacting rim drive and positioning torquer. All sensors used to close the servo loops on the vernier system are noncontacting elements. Therefore, the experiment is a free-flyer constrained only by the magnetic forces generated by the control loops.

Kuo, B. C.↗
NASA NTRS1979

25 kW power module evolution study

This paper presents a study of evolutionary growth concepts for the 25 kW power module to augment STS mission support future capabilities. The study aimed to establish user payload requirements, define evolution methods for system initial operational capability, and formulate a development program and conceptual designs. The payload requirements analysis focused on material processing in space, public services, and solar terrestrial observations; evolutionary system concepts were evaluated to derive the power module and system support requirements, and four reference orbits were used to construct the nominal program scenario. The mission accomodations analysis evaluated the capability of the nominal program scenario and associated power module concepts to meet user needs. Finally, the recommended modular design consisting of electric power, attitude control, thermal control, and command and data handling is described, and it is concluded that the 25 kW power module is a logical first step to support the near term NASA sortie and free-flyer mission requirements.

Overall, J. W., Jr.↗
NASA NTRS1979

A look at the universe in gamma rays

The scientific background and objectives, proposed instruments, spacecraft constraints, operations plans and present status and schedule of the Gamma Ray Observatory (GRO), a shuttle-launched free-flyer satellite currently planned by NASA, are reviewed. Objectives for the satellite study of the highest energy electromagnetic radiation in the cosmos discussed include the investigation of the evolution of compact objects, nucleosynthesis, gamma-ray objects whose nature is not yet known, the gamma-ray properties of the Galaxy and other galaxies, cosmological effects and intense gamma-ray bursts. The five instruments considered in the definition study which span six decades in energy are presented and proposed experiments are outlined. Although a spacecraft has not yet been selected, several feasible alternatives have been identified, and a launch in the mid-1980s is planned.

Kniffen, D. A.↗
NASA NTRS1982

Space manufacturing systems and the Space Operations Center

For the planned Space Operations Center (SOC) and envisioned space manufacturing and processes systems, the concepts of phased programs, development and operations, station-keeping orbit envelopes, propulsive harbor tugs, and aspects of servicing are discussed. The SOC three-phased program concept includes the servicing of satellites in compatible orbits and in transition to higher energy orbits. Two concepts of a free-flyer satellite are assessed, including the fuel system, and the placement of such a satellite into orbit is discussed. Finally, some services that will be provided by SOC are mentioned.

Louviere, A. J.↗
NASA NTRS1983

Earth observation system: Spacecraft design

The Earth Observation Satellite (EOS) was a study funded by NASA Langley Research Center. The study was a system investigation of the total spacecraft integration with its major subsystems and sensors. Mission optimization and ranking using various sensors was also an objective of the contract. Integrating the spacecraft and major subsystems with the large microwave radiometer was done, essentially making the radiometer a free-flyer without an external spacecraft. Another program objective was to provide design and analysis data on microwave radiometer satellites augmented with additional Earth, ocean, and atmospheric sensors. A top-down systems approach resulted in a detailed design integrating subsystems and sensors into the microwave support structure. An important objective of the program was to identify technology needs for Earth observation satellites. The definition and understanding of these design drivers are critical in order to set priorities for future EOS work.

Herbert, J. J.↗
NASA NTRS1984

The electron Echo 6 mechanical deployment systems

The Echo 6 sounding rocket payload was flown on a Terrier boosted Black Brant vehicle on March 30, 1983. The experiment requirements resulted in the new design of a rocket propelled Throw Away Detector System (TADS) with onboard Doppler radar, a free-flyer forward experiment designated the Plasma Diagnostic Package (PDP), and numerous other basic systems. The design, developmental testing, and flight preparations of the payload and the mechanical deployment systems are described.

Meyers, S. C.↗
NASA NTRS1982

Multispectral linear array

The Multispectral Linear Array (MLA) is a solid-state earth imagery radiometer operating in the 'push-broom' mode and using a focal plane containing multiple spectral band linear detector arrays. The MLA sensor offers the capability for increased spatial and spectral resolution with multiple selectable bands and in-orbit operation flexibility. Both free-flyer (satellite) and Shuttle-attached instrument designs have been studied. Four Shuttle-attached MLA instrument design studies were initiated in 1982, and the concepts resulting from these studies are described.

Richard, H. L.↗
NASA NTRS1984

Propellant transfer: Attached depot

Propellant transfer at an attached depot involves: (1) resupply tankers (dedicated launch from the ground or scavenging from the external tank) to resupply the depot; (2) depot storage and supply tanks (attached, free-flyer, or tethered) from which liquid hydrogen and liquid oxygen are transferred to fill the space-based OTV; and (3) the space-based OTV which is resupplied with cryogens from the depot. Liquid storage and supply, thermal control, and transfer/resupply requirements for an attached depot are listed, and technologies defined. The specific fluid management elements and approaches for an attached depot are enumerated. The cryogenic fluid management facility (CFMF) shuttle attached-payload test bed, scheduled for a mid-1988 first launch, is expected to provide much of the needed technology.

Eberhardt, R. N.↗