4 november 1997
De 'extended mission' is afgelopen. We hebben afgelopen maand gedaan wat
we kunnen doen, zonder succes.
"After operating on the surface of Mars three times longer than expected
and returning a tremendous amount of new information about the red planet,
NASA's Mars Pathfinder mission is winding down."
"We concede that the likelihood of hearing from the spacecraft again
diminishes with each day," zegt Pathfinder Project Manager Brian Muirhead.
"We will scale back our efforts to reestablish contact but not give up
entirely. Given that, and the fact that Pathfinder is the first of several
missions to Mars, we'll say 'see you later' instead of saying goodbye."
Op het tijdstip van de laatste gegevens van de pathfinder werkte hij al
drie keer langer dan waar hij voor gemaakt was. De rover werkte zelfs
al 12 keer langer dan verwacht. De Pathfinder was gemaakt voor een maand,
en de rover een week.
"This mission has advanced our knowledge of Mars tremendously and will
surely be a beacon of success for upcoming missions to the red planet,"
vertelt Dr. David Baltimore, president of the California Institute of
Technology, which manages JPL for NASA. "Done quickly and within a very
limited budget, Pathfinder sets a standard for 21st century space
exploration."
"Engineering milestones of the mission included demonstrating a new way
of delivering a spacecraft to the surface of Mars by way of direct entry
into the Martian atmosphere. In addition, Mars Pathfinder demonstrated for
the first time the ability of engineers to deliver a semi-autonomous roving
vehicle capable of conducting science experiments to the surface of another
planet. "
Scientific highlights of the Mars Pathfinder mission are:
- Martian dust includes magnetic, composite particles, with a
mean size of one micron.
- Rock chemistry at the landing site may be different from
Martian meteorites found on Earth, and could be of basaltic andesite composition.
- The soil chemistry of Ares Vallis appears to be similar to
that of the Viking 1 and 2 landing sites.
- The observed atmospheric clarity is higher than was expected
from Earth-based microwave measurements and Hubble Space
Telescope observations.
- Dust is confirmed as the dominant absorber of solar radiation
in Mars' atmosphere, which has important consequences for the
transport of energy in the atmosphere and its circulation.
- Frequent "dust devils" were found with an unmistakable
temperature, wind and pressure signature, and morning
turbulence; at least one may have contained dust (on Sol 62),
suggesting that these gusts are a mechanism for mixing dust
into the atmosphere.
- Evidence of wind abrasion of rocks and dune-shaped deposits
was found, indicating the presence of sand.
- Morning atmospheric obscurations are due to clouds, not ground
fog; Viking could not distinguish between these two
possibilities.
- The weather was similar to the weather encountered by Viking
1; there were rapid pressure and temperature variations,
downslope winds at night and light winds in general.
Temperatures were about 10 degrees warmer than those measured
by Viking 1.
- Diversity of albedos, or variations in the brightness of the
Martian surface, was similar to other observations, but there
was no evidence for the types of crystalline hematite or
pyroxene absorption features detected in other locations on
Mars.
- The atmospheric experiment package recorded a temperature
profile different than expected from microwave measurements
and Hubble observations.
- Rock size distribution was consistent with a flood-related
deposit.
- The moment of inertia of Mars was refined to a corresponding
core radius of between 1,300 kilometers and 2,000 kilometers
(807 miles and 1,242 miles).
- The possible identification of rounded pebbles and cobbles on
the ground, and sockets and pebbles in some rocks, suggests
conglomerates that formed in running water, during a warmer
past in which liquid water was stable.
Einde Extended Mission
De originele tekst van alle gegevens op deze pagina zijn te lezen (in het
Engels) in o.a. de 'Mission status reports' op de Internet-site van NASA:
