This is the description from the
"Yellow Book", NASA SP-473
Interplanetary Dust Experiment (A0201)
S. Fred Singer and John E. Stanley
University of Virginia
Charlottesville, Virginia
Background
The study of interplanetary dust historically has been plagued by the problem
of low data rates and therefore statistically inadequate data analyses. The
LDEF satellite will permit for the first time the flight of an experiment with
a large effective area, yielding data with which excellent statistical
confidence can be achieved. Additionally, it has been shown that a major
source of the interplanetary micrometeoroid enviroments is comets. Confirmation
and expansion of these results may give important insight into the cometary
phenomenon.
Objectives
The objective of this experiment is to study interplanetary dust, variously
referred to as cosmic dust, cometary dust, zodiacal dust, or meteoric dust
particles. Specific objectives are to obtain information regarding particle
mass and velocity, and to undertake correlative analyses with other
experiments, both on LDEF or near the time of the LDEF flight.
Approach
The experiment will use metal-oxide-silicon (MOS) capacitor-type impact
sensors with two different sensitivities. The total active area of the
experiment will be about 1 m^2. Sixty percent of the sensors will have an
oxide thickness of 0.4 micrometers, the higher sensitivity, and 40 percent
will have a thickness of 1.0 micrometers.
The experiment will be located in four locations spaced at 90 degree
intervals around the LDEF periphery and on the Earth-facing and space-facing
ends. (See fig. 59.) Tray requirements include one
6-in.-deep tray, one-third each of three 3-in.-deep trays, one 3-in.-deep
end corner tray on the Earth-facing end, and about one-third of a 3-in.-deep
end corner tray on the space-facing end. A one-third-tray location typically
will contain 80 impact sensors and 1 Sun sensor.
Figure 59.-Interplanetary dust experiment.
Approximately every 2 hours, an experiment power and data system will record
the status of all sensors and the recent experiment activity, which will
include the time of occurence of each impact and the total number of
impacts for each sensitivity and tray location. The Sun sensors will be
used to record the time from the most recent crossing of the dark-to-light
terminator.
When the experiment is recovered, the recorded data and LDEF tracking data
will be analyzed to determine the dust encountered as a function of mass,
time, and velocity direction in geocentric coordinates. These data will then
be correlated with theories and observations of other dust-related
phenomena.
Klaus G. Paul, 4-30-1994