100 lines
5.6 KiB
Plaintext
100 lines
5.6 KiB
Plaintext
. RCA ASTRO RECEIVES CONTRACT FOR MARS OBSERVER
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. The Jet Propulsion Laboratory has selected the Astro-Electronics
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Division of RCA, located in Princeton, New Jersey as spacecraft contractor
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for the Mars Observer mission. This is the first of the Planetary Observers,
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a series of low cost missions for the exploration of the inner solar system.
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. In order to achieve the requisite economies, a new procurement
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philosophy is being utilized. Rather than "reinvent the wheel" by designing
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a new vehicle from scratch for each mission, JPL's approach emphasizes use
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of existing, production line spacecraft designs and technology, particularly
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platforms originally designed as Earth-orbiting communication or weather
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satellites. These will be refitted for the contemplated mission by the
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addition of scientific instruments, chosen to fit within the constraints of
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the existing spacecraft design, and whatever engineering modifications may be
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appropriate to transform an Earth-orbital satellite into a spacecraft capable
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of traveling to and conducting experiments at other bodies in the inner solar
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system. In the case of the Mars Observer, the spacecraft selected after a
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competitive procurement process will be based on RCA Astro's SATCOM
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communications satellite. The electronic subsystems will use proven designs
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from the TIROS and DMSP series of meterological satellites.
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. Present plans call for the spacecraft to be launched on an August 1990
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Space Shuttle mission. An upper stage will then be used to inject it into an
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interplanetary transfer orbit. The upper stage which has been selected for
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the mission is the Transfer Orbit Stage (TOS) which has been developed by
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Orbital Sciences Corporation of Vienna, Virginia as a privately financed
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venture. After approximately a one year transit flight, the spacecraft will
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arrive in the Martian vicinity and go into orbit around the planet. The
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initial orbit will be adjusted into a nearly circular, sun-synchronous, low
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altitude polar orbit. The probe's mission is to last for one Martian year,
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slightly less than two Earth years. Scientific objectives are modest and
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well defined. The principal purpose of the Mars Observer mission is to flesh
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out knowledge gained by the Mariner and Viking missions of the 1960's and
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70's. The spacecraft will gather geoscience date by repetitive mapping of
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the Martian surface and climatological data by observation of the seasonal
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variation of the planet's atmosphere. It is hoped that this will resolve
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still unanswered questions about the Martian surface and atmosphere and how
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they interact.
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. Mission operations for the Mars Observer as well as future planetary
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observer missions will be conducted from a new multimission operations
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facility at JPL called the Space Flight Operations Center.
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. AN EXCURSION INTO HISTORY
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. The Mars Observer program is in way a reminder of just how far we've
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come in a relatively short period of time. Mars makes its closest approach
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to the Earth, about thirty-five million miles, once every seventeen years.
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(The last such event occurred in 1971, and the next will be two years from
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now in 1988.) These used to be eagerly anticipated by astronomers who, on
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each such occasion hoped to unravel some of the mysteries of the Red Planet.
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. The excitement began in the Nineteenth Century when the Italian
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astronomer Giovanni Schiaparelli reported he had observed some dark lines on
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the Martian surface which he called "canali." In Italian this simply means
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"channels." However, the coincidence with the English word "canal"
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immediately fueled speculation that Mars supported not only intelligent life
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but an advanced civilization capable of undertaking a planet-wide engineering
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project, the construction of a vast irrigation system to bring water from the
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planets polar caps to its arid desert regions. (Today it is theorized that
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what Schiaparelli actually saw may have been chains of craters on the Martian
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surface. In his relatively small telescope these appeared to be linked
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together to form a continuous line.)
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. The possibility that Mars might be inhabited inspired, among other
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things, H. G. Well's classic story The War of the Worlds, which depicted a
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Martian invasion of the Earth. When produced as a radio program by Orson
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Wells in 1938, this created panic among listeners who thought they had tuned
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into a newscast instead of a drama. On a more serious scientific level, some
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reports say that during Mars 1937 approach the Navy ordered its ships to
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confine their radio traffic to essential messages so as to enhance the
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likelihood of picking up possible Martian transmissions. Not to be outdone,
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the Army had team of cryptoanalysts headed by William Friedman (who on the
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eve of the Second World War would break the Japanese PURPLE code) standing by
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to decipher any messages received.
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. The 1954 event was likewise eagerly awaited. This would be the first
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occasion on which Mars could be observed through the 200 inch Mount Palomar
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telescope. It was hoped that this instrument could not only confirm the
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existence of the "canali" but determine if they followed great circle
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tracks, which would be evidence of artificial construction. One writer
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looked beyond 1954 to the 1971 apparition and stated that it was not too
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much to expect that there might be a telescope outside the Earth's
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atmosphere by that point, although even he did not venture to predict that
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by then spacecraft from Earth would have flown by the planet.
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