Engineering topics

Fester, D. A.

Publications and source records attributed to Fester, D. A..

At least 19 records

NASA NTRS1988

Integration of Space Station propulsion and fluid systems

The benefits which would be gained by providing commonality and integration of propulsion and fluid systems associated with various elements of the Space Station are discussed and the results of the integrated propulsion system assessment are presented. The O2/H2 propulsion system with and without resistojets, the integration of O2/H2 systems across the Space Station elements, and an approach for handling waste fluids available for resistojet venting are evaluated. It is shown that major benefits can be gained through commonality and integration. Several systems are recommended, including a gaseous O2/H2 propulsion system with resistojets, a Bosch CO2 reduction process, and pumping electrolysis units.

Bicknell, B. A.↗

NASA NTRS1986

Comparison of a tethered to a zero-gravity refueling facility

The space-based orbital transfer vehicle will require a large cryogenic fuel storage facility at the Space Station. An alternative to fuel storage on-board the Space Station is on a tethered orbital refueling facility (TORF) which is separated from the Space Station by a sufficient distance to induce a gravity gradient to settle the propellants. Overall costs and benefits of a particular tethered facility design have been defined relative to a representative zero-gravity facility on the Space Station. Results indicate that the TORF hardware and operations costs are roughly 40 percent higher than the comparable zero-g facility costs. The cost difference is negligible when compared to the launch cost of the fuel over the facility 10-year lifetime.

Kiefel, E. R.↗

NASA NTRS1986

Tethered orbital refueling study

Objectives are to evaluate the feasibility and limitations of fluid acquisition and transfer under an accleration induced in a tethered orbital refueling facility and to provide conceptual designs. Program tasks consist of recommendation of fluid transfer method and parameters; evaluation of disturbances, fluid motion, and damping; selection of passive devices to augment inherent fluid damping and determination of the resultant envelope of operation; assessment of the effect of tether lengths on hazards; and identification of ground and flight tests necessary to prove the tethered orbital refueling concepts.

Fester, D. A.↗

NASA NTRS1986

The dynamics of a space station tethered refueling facility

The fluid stored in a tethered orbital refueling facility is settled at the bottom of the storage tanks by gravity-gradient forces. The fluid motions (slosh) induced by outside disturbances must be limited to ensure the tank outlet is not uncovered during a fluid transfer. The dynamics of a LO2/LH2 TORF attached to the space station have been analyzed to identify design parameters necessary to limit fluid motion. Using the worst case disturbance of a shuttle docking at the space station, the fluid motion was found to be a function of tether length and allowable facility swing angle. Acceptable fluid behavior occurs for tether lengths of at least 1000 ft. To ensure motions induced by separate disturbances do not add to unacceptable values, a slosh damping coefficient of 5 percent is recommended.

Abbott, P.↗

NASA NTRS1986

Space Station tethered refueling facility operations

The space-based orbital transfer vehicle will require a large cryogenic fuel storage facility at the Space Station. An alternative to fuel storage onboard the Space Station, is on a tethered orbital refueling facility (TORF) which is separated from the Space Station by a sufficient distance to induce a gravity gradient to settle the propellants. Facility operations are a major concern associated with a tethered LO2/LH2 storage depot. A study was carried out to analyze these operations so as to identify the preferred TORF deployment direction (up or down) and whether the TORF should be permanently or intermittently deployed. The analyses considered safety, contamination, rendezvous, servicing, transportation rate, communication, and viewing. An upwardly, intermittently deployed facility is the preferred configuration for a tethered cryogenic fuel storage.

Kiefel, E. R.↗

NASA NTRS1985

LH2 on-orbit storage tank support trunnion design and verification

A detailed fatigue analysis was conducted to provide verification of the trunnion design in the reusable Cryogenic Fluid Management Facility for Shuttle flights and to assess the performance capability of the trunnion E-glass/S-glass epoxy composite material. Basic material property data at ambient and liquid hydrogen temperatures support the adequacy of the epoxy composite for seven-mission requirement. Testing of trunnions fabricated to the flight design has verified adequate strength and fatigue properties of the design to meet the requirements of seven Shuttle flights.

Bailey, W. J.↗

NASA NTRS1985

A Space Station tethered orbital refueling facility

A planned function of the Space Station is to refurbish and refuel an advanced space-based LO2/LH2 orbit transfer vehicle. An alternative to propellant storage at the station is to use a remote facility tied to the station with a long tether. Preliminary design of such a facility is described with emphasis on fluid transfer and storage requirements. Using tether lengths of at least 300 ft, gravity gradient forces will dominate surface tension in such a system. Although gravity driven transfer is difficult because of line pressure drops, fluid settling over the tank outlet greatly alleviates acquisition concerns and will facilitate vented tank fills. The major concern with a tethered orbital refueling facility is its considerable operational complexity including transport of the OTV to and from the facility.

Fester, D. A.↗

NASA NTRS1985

Tethered orbital propellant depot

A planned function of the Space Station is to refurbish and refuel an advanced space-based LO2/LH2 orbit transfer vehicle. An alternative to propellant storage at the station is to use a remote facility tied to the station with a log tether. Preliminary design of such a facility is described with emphasis on fluid transfer and storage requirements. Using tether lengths of at least 300 ft, gravity gradient forces will dominate surface tension in such a system. Although gravity given transfer is difficult because of line pressure drops, fluid settling over the tank outlet greatly alleviates acquisition concerns and will facilitate vented tank fills. The major concern with a tethered orbital refueling facility is its considerable operational complexity including transport of the OTV to and from the facility.

Fester, D. A.↗

NASA NTRS1984

On-orbit cryogenic storage and resupply

Methods of integrating pressure control, liquid acquisition, and liquid transfer concepts for the Cryogenic Fluid Management Facility, a reusable test bed in the Shuttle cargo bay studying the efficient management of cryogens in space, are investigated. Significant design data and criteria for future subcritical cryogenic storage and transfer systems are presented. Technology requirements for liquid storage/supply systems, thermal control systems, and fluid transfer/resupply are addressed, and fluid and thermal analysis pertaining to receiver tank chilldown and no-vent fill of the receiver tank are discussed.

Eberhardt, R. N.↗

NASA NTRS1983

Cryogenic Fluid Management Experiment (CFME) trunnion verification testing

The Cryogenic Fluid Management Experiment (CFME) was designed to characterize subcritical liquid hydrogen storage and expulsion in the low-g space environment. The CFME has now become the storage and supply tank for the Cryogenic Fluid Management Facility, which includes transfer line and receiver tanks, as well. The liquid hydrogen storage and supply vessel is supported within a vacuum jacket to two fiberglass/epoxy composite trunnions which were analyzed and designed. Analysis using the limited available data indicated the trunnion was the most fatigue critical component in the storage vessel. Before committing the complete storage tank assembly to environmental testing, an experimental assessment was performed to verify the capability of the trunnion design to withstand expected vibration and loading conditions. Three tasks were conducted to evaluate trunnion integrity. The first determined the fatigue properties of the trunnion composite laminate materials. Tests at both ambient and liquid hydrogen temperatures showed composite material fatigue properties far in excess of those expected. Next, an assessment of the adequacy of the trunnion designs was performed (based on the tested material properties).

Bailey, W. J.↗

NASA NTRS1983

Cryogenic fluid management experiment trunnion fatigue verification

A subcritical liquid hydrogen orbital storage and transfer experiment was designed for flight in the Shuttle cargo bay. The Cryogenic Fluid Management Experiment (CFME) includes a liquid hydrogen tank supported in a vacuum jacket by two fiberglass epoxy trunnion mounts. This composite material was selected for the trunnions since it provides desirable strength, weight and thermal characteristics for supporting cryogenic tankage. An experimental program was conducted to provide material property and fatigue data for S-glass epoxy composite materials at ambient and liquid hydrogen temperatures and to verify structural integrity of the CFME trunnion supports.

Bailey, W. J.↗

NASA NTRS1982

Long term storage of cryogens in space

Experimental design procedures leading to the configuration of a space-based cryogenic fluids test system are reported. Large quantities of cryogenic fluids are expected to be required in space for cooling systems, chemical and electrical OTVs, and resupply tankers. The design was guided by the necessity for representative storage and supply systems to be compatible with the Shuttle. Consideration was given to liquid hydrogen, oxygen, methane, and argon containers and concommitant fluid dynamics, thermal, and structural analyses. A 5% initial ullage was included for the liquids, except for methane, which was calculated at 8.9%. The Ar, CH4, and O2 tanks were set at 12.5 cu m, while the H2 tank was 37.4 cu m. The orbital experiment is required to provide actual thermal stabilization lags in a zero-g environment. Details of the Cryogenic Fluid Management Facility test module for flight on board the Shuttle are presented.

Fester, D. A.↗

NASA NTRS1981

Cryogenic fluid management experiment

The cryogenic fluid management experiment (CFME), designed to characterize subcritical liquid hydrogen storage and expulsion in the low-q space environment, is discussed. The experiment utilizes a fine mesh screen fluid management device to accomplish gas-free liquid expulsion and a thermodynamic vent system to intercept heat leak and control tank pressure. The experiment design evolved from a single flight prototype to provision for a multimission (up to 7) capability. A detailed design of the CFME, a dynamic test article, and dedicated ground support equipment were generated. All materials and parts were identified, and components were selected and specifications prepared. Long lead titanium pressurant spheres and the flight tape recorder and ground reproduce unit were procured. Experiment integration with the shuttle orbiter, Spacelab, and KSC ground operations was coordinated with the appropriate NASA centers, and experiment interfaces were defined. Phase 1 ground and flight safety reviews were conducted. Costs were estimated for fabrication and assembly of the CFME, which will become the storage and supply tank for a cryogenic fluid management facility to investigate fluid management in space.

Eberhardt, R. N.↗

NASA NTRS1981

An experiment to evaluate liquid hydrogen storage in space

The design and verification of a Cryogenic Fluid Management Experiment for orbital operation on the Shuttle is described. The experiment will furnish engineering data to establish design criteria for storage and supply of cryogenic fluids, mainly hydrogen, for use in low gravity environments. The apparatus comprises an LAD (liquid acquisition device) and a TVS (thermodynamic vent system). The hydrogen will be either vented or forced out by injected helium and the flow rates will be monitored. The data will be compared with ground-based simulations to determine optimal flow rates for the pressurizing gas and the release of the cryogenic fluid. It is noted that tests on a one-g, one-third size LAD system are under way.

Eberhardt, R. N.↗

NASA NTRS1981

Shuttle compatible cryogenic liquid storage and supply systems

A detailed introduction is given to a wide variety of orbital cryogenic liquid storage and supply systems required for future vehicles by NASA and DOD. The systems include small cooling applications, large chemical and electrical orbit transfer vehicles and resupply tankers, and all have the common requirements of low-g fluid management for the accomplishment of gas-free liquid expulsion, and efficient thermal control in order to manage heat leak and tank pressure. The present study considers hydrogen, oxygen, methane, argon and helium tanks ranging from 0.6 to 37.4 cu m. Conceptual designs were generated for each tank system, and fluid dynamic, structural and thermal analyses were performed in view of Shuttle requirements.

Eberhardt, R. N.↗

NASA NTRS1980

A liquid hydrogen experiment as a Shuttle payload

The paper describes the cryogenic fluid management experiment (CFME) as a Shuttle payload. The experiment includes a liquid hydrogen tank containing a fine-mesh screen acquisition device, and a thermal control system consisting of a thermodynamic vent system to intercept heat leak to the hydrogen tank and control tank pressure. Engineering data obtained will be used to establish design criteria for subcritical cryogenic storage and supply tankage.

Eberhardt, R. N.↗

NASA NTRS1977

Fluid interaction with spinning toroidal tanks

An experimental study was conducted to evaluate propellant behavior in spinning torroidal tanks that could be used in a retropropulsion system of an advanced outer-planet Pioneer orbiter. Information on propellant slosh and settling and on ullage orientation and stability was obtained. The effects of axial acceleration, spin rate, spin-rate change, and spacecraft wobble, both singly and in combination, were evaluated using a one-eighth scale transparent tank in one-g and low-g environments. Liquid loadings ranged from 5% to 96% full. The impact of a surface tension acquisition device was assessed by comparison with bare-tank results. The testing simulated the behavior of the fluorine/hydrazine and nitrogen textroxide/monomethylhydrazine propellants. Results are presented that indicate that no major fluid behavior problems would be encountered with any of the four propellants in the toroidal tanks of a spin-stabilized orbiter spacecraft.

Fester, D. A.↗

NASA NTRS1977

Toroidal tank evaluation

The reported study had been conducted to determine the feasibility of developing toroidal tanks for an auxiliary propulsion system that could be integrated into a Pioneer spin-stabilized spacecraft. The system evaluated consisted of two toroidal tanks equipped with surface tension devices. One tank is intended for nitrogen tetroxide, the other for monomethylhydrazine. The study included the definition of a propellant acquisition system concept that could satisfy the requirements of a spinning tank. It was found that an oxidizer tank spin rate of 76 rpm and a fuel tank spin rate of 110 rpm would be required to produce liquid loss from the acquisition system during spacecraft operation. An investigation showed that toroidal tanks can be fabricated with present technology using either titanium or aluminum alloys. The preferred material would be titanium because of its significantly higher strength.

Fester, D. A.↗