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Ford, F. E.

Publications and source records attributed to Ford, F. E..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

Analytical Modeling of Spacecraft Power Systems

During the 25 years of space flight with unmanned Earth orbiting satellites, there has been an evolution of power systems in three general areas. The size of power system in terms of power demand at the bus has increased frorm a few watts in the early 1960s to a few hundred watts during the 1970s. Today, the bus power requirements are typically in the .5 to 1 kw range with some mission requirements exceeding the 1 kw size. Power grounding and user isolation are major design considerations when high fidelity power is required by a user.

Ford, F. E.↗
NASA NTRS1984

Electrical System Technology Working Group (WG) Report

The technology needs for space power systems (military, public, commercial) were assessed for the period 1995 to 2005 in the area of power management and distribution, components, circuits, subsystems, controls and autonomy, modeling and simulation. There was general agreement that the military requirements for pulse power would be the dominant factor in the growth of power systems. However, the growth of conventional power to the 100 to 250kw range would be in the public sector, with low Earth orbit needs being the driver toward large 100kw systems. An overall philosophy for large power system development is also described.

Silverman, S.↗
NASA NTRS1983

Assessment of Potential for Batteries in Space Applications

Different battery technologies for energy storage in space missions were examined. One of the best ways of the possibilities of high energy density batteries were determined by looking at more conventional batteries (i.e., lead-acid, nickel-cadmium, nickel-hydrogen, etc.). The theoretical specific energy density for state of the art batteries and the usable energy density for a reasonable life expectancy are outlined. The most mature of these couples is lead acid, which achieves nearly 20% of its theoretical capacity. The nickel-cadmium couple, has matured to where the active capacity is 17% of its theoretical capacity. The achievements are used to measure the practicality of more advanced batteries and to estimate what is needed for future high power space systems.

Ford, F. E.↗
NASA NTRS1980

The characteristics and limitations of the MPS/MMS battery charging system

A series of tests was conducted on two 12 ampere hour nickel cadmium batteries under a simulated cycle regime using the multiple voltage versus temperature levels designed into the modular power system (MPS). These tests included: battery recharge as a function of voltage control level; temperature imbalance between two parallel batteries; a shorted or partially shorted cell in one of the two parallel batteries; impedance imbalance of one of the parallel battery circuits; and disabling and enabling one of the batteries from the bus at various charge and discharge states. The results demonstrate that the eight commandable voltage versus temperature levels designed into the MPS provide a very flexible system that not only can accommodate a wide range of normal power system operation, but also provides a high degree of flexibility in responding to abnormal operating conditions.

Ford, F. E.↗
NASA NTRS1978

Battery workshop

The workshop was attended by representatives from industry and government. The requirements for energy storage and the plans for battery development were reviewed. The workshop followed a debate format, with the objective of recommending improvements to the development plans presented by NASA and the Air Force. The issues addressed were: (1) significant technology deficiencies which can be identified; (2) adequacy of current and proposed programs to resolve the technology deficiencies identified; (3) additional tasks which should be undertaken, including benefits and timing; and (4) lowest priority items in the presently planned program, both in content and in timing.

Sparks, R. H.↗
NASA NTRS1977

Orbiting solar observatory battery and power design

The OSO-1 represents a recent vintage satellite, or more recent design satellite. A summary of the battery design used on OSO-1 is presented. The temperature effects on voltage and charging-discharging of the battery system are discussed.

Ford, F. E.↗
NASA NTRS1977

Orbiting astronomical observatory battery and power system design

The battery design of OAO-C (OAO-3) is given and consists of three-20 ampere hour 22 series connected cells in the battery. There are three batteries per spacecraft. The packaging configuration is described. The charging-discharging operations and the voltage potential of the battery system are discussed. Graphs are presented for the voltage limits (battery voltage versus temperature) and end of dark voltages (battery voltage versus ampere-hours discharged) of the battery system used on OAO-3. Data tables are also presented which give a summary of the battery performance and a comparison of OAO-3 with OAO A-2.

Ford, F. E.↗
NASA NTRS1977

Applications technology satellites battery and power system design

A summary of the ATS battery design which is onboard the Applications Technology Satellite (ATS) is provided. The 15 ampere hour nickel cadmium cells were manufactured by Gulton, 19 series connected cells per battery, and there are two batteries in each spacecraft. The operating design life was two years in a synchronous orbit, and a maximum depth of discharge of 50 percent. The design temperature for the batteries in the spacecraft was 0 to 25 C, and the charge control consisted of 1 volt versus temperature on a constant percentage voltage. Also, C/10 current limit, and a commandable trickle charge rate, using C/20 or C/60. The undervoltage was sent across a 9 cell and a 10 cell group, and it was set at one volt average per group on either group.

Ford, F. E.↗
NASA NTRS1977

Accelerated test program

A brief discussion on the accelerated testing of batteries is given. The statistical analysis and the various aspects of the modeling that was done and the results attained from the model are also briefly discussed.

Ford, F. E.↗
NASA NTRS1977

Effects of periodic discharges

Periodic capacity checks are assessed as well as the effects of periodic discharges on the cycle life and the performance of cells during the cycle life. Topics discussed include the effect of the amount of electrolyte on cell capacity at 35 C; battery design for spacecraft; electrolyte starvation theory; battery separator degradation; negative electrode stability; voltage regulation; operating temperatures; and integration of reconditioning systems using microprocessors.

Ford, F. E.↗
NASA NTRS1972

Characterization of the 20-Ah nickel-cadmium cell used for energy storage on the Orbiting Astronomical Observatory

Tests were conducted on 20-Ah sealed nickel cadmium cells to evaluate initial and long-term performance at various charge rates, temperatures and voltage-control levels. An average ampere-hour recharge of 103 percent per orbit at 13 C was able to maintain cell capacity; required watt-hour recharge on an orbital basis was 8 to 10 percent greater than required ampere-hour recharge. Cells exhibited an early life burn-in characteristic. A discharge after periods of repetitive cycling yielded two voltage plateaus which were temporarily eliminated by the discharge.

Ford, F. E.↗
NASA NTRS1972

Progress in electrochemical storage for battery systems

Efforts to improve electrochemical systems for space use relate to: (1) improvement of conventional systems; (2) development of fuel cells to practical power systems; and (3) a search for new systems that provide gains in energy density but offer comparable life and performance as conventional systems. Improvements in sealed conventional systems resulted in the areas of materials, charge control methods, cell operations and battery control, and specific process controls required during cell manufacture. Fuel-cell systems have been developed for spacecraft but the use of these power plants is limited. For present and planned flights, nickel-cadmium, silver-zinc, and silver-cadmium systems will be used. Improvements in nickel-cadmium batteries have been applied in medical and commercial areas.

Ford, F. E.↗
NASA NTRS1972

Performance of 3rd electrode cells in OAO.

The OAO 2 satellite employed nickel-cadmium batteries with auxiliary (signal) electrodes for overcharge control. During the early life of the satellite, these third-electrode signals provided an orbit-by-orbit indication of the overcharge received by the batteries. By ground command, the battery charger was adjusted on a need basis to provide optimum recharge conditions as indicated by the third-electrode signals during all phases of spacecraft operation and orientation. After more than two years, an unusual degradation in third-electrode signals was observed, providing the first indication of battery degradation. The present paper examines the operation of the battery system and analyzes the battery degradation mechanism. The abnormal performance of the third electrode is related to cell-voltage divergence during periods of overcharge. Cells that had a higher cell voltage showed signs (third-electrode degradation) of small amounts of hydrogen gas generation.

Ford, F. E.↗