Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/jplnews/0456.ZIP/0456.PR

Text File | 1993-04-21 | 3KB | 57 lines

OFFICE OF PUBLIC INFORMATION
JET PROPULSION LABORATORY, CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA.  TELEPHONE [phone]

FOR IMMEDIATE RELEASE:  Friday, September 15, 1967

          The Mariner IV spacecraft last night was buffeted about
in interplanetary space between the orbits of Earth and Mars when
it apparently crossed the path of a stream of micrometeoroids.
          The 575-pound spacecraft, which was launched in Novem-
ber, 1964, and photographed Mars in July, 1965, was pelted with
at least 17 pieces of meteoric matter during a seven-minute
period beginning at 7:54 p.m. Pacific Daylight Time.
          Numerous other bits could have occurred, project offi-
cials pointed out, in addition to those observed acoustically by
the microphone portion of Mariner IV's cosmic dust detector.
          The spacecraft apparently was not damaged by the encoun-
ter with the interplanetary debris.  Mariner responded to a
routine command which was being prepared before the hits occurred
and was transmitted when the disturbance ended.  No loss of power
from the solar panels was noted, and the on-board attitude control
system was able to stabilize the rocking motion of the spacecraft.
          Other data received in the Mariner command center at the
Jet Propulsion Laboratory during the meteor shower included:
          ...Unusual brightness observed by the spacecraft's
Canopus sensor indicating the sensor may have been following light
reflected from micrometeorites or hair-thin particles knocked
loose from Mariner during one or more hits.
          ...A slight drop in the level of Mariner IV's radio
signal received at the Deep Space Network station at Goldstone,

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Calif., at 8 p.m. -- the instant that a cluster of five hits was
recorded.
          ...A disturbance in the pitch and yaw axes of the space-
craft which required nearly an hour for the attitude control
system to overcome by firing spurts of nitrogen gas.
          ...A slight drop in spacecraft temperatures -- about
one degree -- appeared in the telemetry during the same time
frame indicating Mariner's thermal shield may have been altered
by minute particles.
          When the disturbance occurred, Mariner IV was about
29.6 million miles from Earth and had completed nearly 1.4 billion
miles of flight in 1020 days since launch.
          During the past few months, Mariner IV has been tracked
in a combined operations effort with its sister ship, Mariner V,
now enroute to a flyby of the planet Venus next October 19.


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