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Ferebee, Melvin J., Jr.

Publications and source records attributed to Ferebee, Melvin J., Jr..

11 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2002

Revolutionary Aerospace Systems Concepts - Planning for the Future of Technology Investments

In January, 2000, the NASA Administrator gave the following directions to Langley: "We will create a new role for Langley as a leader for the assessment of revolutionary aerospace system concepts and architectures, and provide resources needed to assure technology breakthroughs will be there to support these advanced concepts. This is critical in determining how NASA can best invest its resources to enable future missions." The key objective of the RASC team is to look beyond current research and technology (R&T) programs and missions and evolutionary technology development approaches with a "top-down" perspective to explore possible new mission capabilities. The accomplishment of this objective will allow NASA to provide the ability to go anywhere, anytime - safely, and affordably- to meet its strategic goals for exploration, science, and commercialization. The RASC Team will seek to maximize the cross-Enterprise benefits of these revolutionary capabilities as it defines the revolutionary enabling technology areas and performance levels needed. The product of the RASC Team studies will be revolutionary systems concepts along with enabling technologies and payoffs in new mission capabilities, which these concepts can provide. These results will be delivered to the NASA Enterprises and the NASA Chief Technologist for use in planning revolutionary future NASA R&T program investments.

Ferebee, Melvin J., Jr.↗
NASA NTRS1997

Satellite Systems Design/Simulation Environment: A Systems Approach to Pre-Phase A Design

A toolset for the rapid development of small satellite systems has been created. The objective of this tool is to support the definition of spacecraft mission concepts to satisfy a given set of mission and instrument requirements. The objective of this report is to provide an introduction to understanding and using the SMALLSAT Model. SMALLSAT is a computer-aided Phase A design and technology evaluation tool for small satellites. SMALLSAT enables satellite designers, mission planners, and technology program managers to observe the likely consequences of their decisions in terms of satellite configuration, non-recurring and recurring cost, and mission life cycle costs and availability statistics. It was developed by Princeton Synergetic, Inc. and User Systems, Inc. as a revision of the previous TECHSAT Phase A design tool, which modeled medium-sized Earth observation satellites. Both TECHSAT and SMALLSAT were developed for NASA.

Ferebee, Melvin J., Jr.↗
NASA NTRS1991

Optimization of payload placement on arbitrary spacecraft

A systematic method for determining the optical placement of instrumentation on an arbitrary spacecraft is described. The method maximizes the resource utilization by minimizing the spacecraft's need for propulsive attitude control. The mathematical program developed with considerations toward reducing the size of the optimization effort is presented.

Ferebee, Melvin J., Jr.↗
NASA NTRS1991

Hoop column soil moisture spacecraft in low Earth orbit for global change monitoring

A subset of the total Global Change Technology Initiative instruments are required to be in low Earth, sunsynchronous orbits. There is one instrument, however, that requires its own specialized spacecraft; the Soil Moisture Microwave Radiometer (SMMR). The characteristic structure of the instrument is the 118 m hoop column support structure. The hoop is supported by an axially placed column. Tension cables support and shape an electromagnetically reflective mesh surface. The instrument is capable of detecting frequencies in the 1.4 GHz range (Soil Moisture and Sea Salinity). Three apertures are used to reduce the degree of paraboloid offset and improve the beam quality. The spacecraft configuration is determined by the instrument support requirements and the requirement that it can fit into the Titan IV cargo bay. The configuration is derived by cross referencing the instrument performance requirements with the performance of the spacecraft. The spacecraft design is similar with the Multi-mission Modular Spacecraft in terms of size and packaging. A description of the spacecraft's features will yield a summary of the technologies needed for the SMMR spacecraft.

Ferebee, Melvin J., Jr.↗
NASA NTRS1991

Optimization of vehicle weight for Mars excursion missions

The excursion class mission to Mars is defined as a mission with one year durations coupled with a stay time of up to 30 days. The fuel budget for such a mission is investigated. The overall figure of merit in such an assessment is the vehicle weight ratio, the ratio between the wet vehicle weight to the dry vehicle weight. It is necessary to minimize the overall fuel budget for the mission in order to maximize the benefits that could be obtained by sending humans to Mars. Assumptions used in the analysis are: each mission will depart and terminate in low-earth-orbit (LEO) (500 km circular) and the maximum stay time at Mars is 30 days. The maximum mission duration is one year (355-375 days). The mass returned to LEO is 135,000 kg, the dropoff mass left at Mars is 168,000 kg. Three propulsive techniques for atmospheric interface are investigated: aerobraking, all-chemical propulsion, and nuclear thermal propulsion. By defining the fuel requirements, the space transfer vehicle's configuration is defined.

Ferebee, Melvin J., Jr.↗
NASA NTRS1991

Benefits from synergies and advanced technologies for an advanced-technology space station

A configuration for a second-generation advanced technology space station has been defined in a series of NASA-sponsored studies. Definitions of subsystems specifically addressed opportunities for beneficial synergistic interactions and those potential synergies and their benefits are identified. One of the more significant synergistic benefits involves the multi-function utilization of water within a large system that generates artificial gravity by rotation. In such a system, water not only provides the necessary crew life support, but also serves as counterrotator mass, as moveable ballast, and as a source for propellant gases. Additionally, the synergistic effects between advanced technology materials, operation at reduced artificial gravity, and lower cabin atmospheric pressure levels show beneficial interactions that can be quantified in terms of reduced mass to orbit.

Garrett, L. Bernard↗
NASA NTRS1988

Systems analysis of a low-acceleration research facility

The Low-Acceleration Research Facility (LARF), an unmanned free-flier that is boosted from low-earth orbit to a desired altitude using an orbital transfer vehicle is discussed. Design techniques used to minimize acceleration-causing disturbances and to create an ultra-quiet workshop are discussed, focusing on residual acceleration induced by the environment, the spacecraft and experiments. The selection and integration of critical subsystems, such as electrical power and thermal control, that enable the LARf to accomodate sub-microgravity levels for extended periods of time are presented, including a discussion of the Low-Acceleration Module, which will supply the payload with 25.0 kW of power, and up to 11.8 kW in the low-power mode. Also, the data management, communications, guidance, navigation and control, and structural features of supporting subsystems are examined.

Martin, Gary L.↗
NASA NTRS1988

Advanced satellite servicing facility studies

A NASA-sponsored systems analysis designed to identify and recommend advanced subsystems and technologies specifically for a manned Sun-synchronous platform for satellite management is discussed. An overview of system design, manned and unmanned servicing facilities, and representative mission scenarios are given. Mission areas discussed include facility based satellite assembly, checkout, deployment, refueling, repair, and systems upgrade. The ferrying of materials and consumables to and from manufacturing platforms, deorbit, removal, repositioning, or salvage of satellites and debris, and crew rescue of any other manned vehicles are also examined. Impacted subsytems discussed include guidance navigation and control, propulsion, data management, power, thermal control, structures, life support, and radiation management. In addition, technology issues which would have significant impacts on the system design are discussed.

Qualls, Garry D.↗
NASA NTRS1988

Advanced Technology Space Station studies at Langley Research Center

The paper describes the Advanced Technology Space Station systems studies at Langley Research Center, which were initiated to identify the technologies required for the construction of a high-performance station in the first quarter of the 21st century. Technologies which would maximize the synergistic effects between the subsystems and structural configurations were selected. The ECLSS and propulsion systems show promising synergistic relationships in the areas of oxygen and hydrogen production and attitude control.

Ferebee, Melvin J., Jr.↗
NASA NTRS1987

Optimization of payload mass placement in a dual keel space station

In order to keep a Space Station in a stable low-Earth orbit, angular momentum storage and translational attitude control systems will have to be used. In order to minimize the size of these attitude control systems, the induced gravity gradient torque effects will have to be minimized. This can be done by minimizing the cross-products of inertia of the Station through the management of payload placement with the Station geometry. A derived and automated methodology is presented which utilizes mathematical nonlinear programming techniques. An optimal arrangement of a set of five payloads on a Dual Keel Space Station was found that minimized the cross products of inertia and thus the required controllability resources.

Ferebee, Melvin J., Jr.↗