# Accession Number:

## ADA064754

# Title:

## Spacecraft Charging.

# Descriptive Note:

## Master's thesis,

# Corporate Author:

## AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING

# Personal Author(s):

# Report Date:

## 1978-12-01

# Pagination or Media Count:

## 105.0

# Abstract:

If a spacecraft is exposed to steady stream of current density, the charge of which is deposited on the surface of a cylindrical conducting spacecraft, internal electromagnetic fields are generated. If the internal fields are of sufficient strength, undesirable electronic noise or damage may result. This thesis presents three approaches for calculating the induced Electric field Separation of variables, variational calculus, and the use of Greens functions. The spacecraft is modeled as a hollow, infinite cylinder. The fields are calculated for the case in which the incoming current is incident perpendicularly to the longitudinal axis of the cylinder. Basic electro-static theory reveals that the governing equation for the potential is Laplaces Equation, subject to Neumann boundary conditions. This equation is first solved by separation of variables. The electric field predicted for representive values in incoming current density are on the order of 10 to the minus 7th power voltsmeter. The Greens function approximations of the potential distribution were consistent with analytic results to at least two significant figures.

# Descriptors:

- *SPACECRAFT
- *ELECTRIC FIELDS
- *ELECTROSTATIC CHARGE
- COMPUTER PROGRAMS
- MATHEMATICAL MODELS
- ELECTROMAGNETIC FIELDS
- MATRICES(MATHEMATICS)
- THESES
- APPROXIMATION(MATHEMATICS)
- BOUNDARY VALUE PROBLEMS
- ELECTROMAGNETIC INTERFERENCE
- DIFFERENTIAL EQUATIONS
- GREENS FUNCTIONS
- INTEGRAL EQUATIONS
- ITERATIONS
- DISTRIBUTION FUNCTIONS
- VARIATIONAL METHODS
- NOISE(ELECTRICAL AND ELECTROMAGNETIC)
- LAPLACE TRANSFORMATION

# Subject Categories:

- Statistics and Probability
- Electricity and Magnetism
- Unmanned Spacecraft