On this day in engineering history, Pioneer 10 became the
first spacecraft to flyby Jupiter, the fifth planet from the Sun and the
largest planet in Earth's solar system.
Launched from Florida's Cape Canaveral Air Force Station
(CCAFS) on March 3, 1972, Pioneer 10 provided the National Aeronautics and
Space Administration (NASA) with its first images both of Jupiter's atmosphere
and several Jovian moons.
A year and a day later, another NASA spacecraft,
Pioneer 11, made its closest approach to Jupiter, a gas giant whose upper
atmosphere is composed mainly of hydrogen and helium.
Powerful Pioneer
Propelled into space by an Atlas/Centaur launch vehicle,
Pioneer 10 was built by TRW Inc. and managed by the NASA
Ames Research
Center at Moffet Field, California.
Like the unmanned Voyager spacecraft of the late 1970s, the 258-kg (569-lb.) Pioneer
probe was powered by radioisotope thermoelectric generators (RTGs) containing
plutonium-238, a radioactive isotope of plutonium (PU) with a half-life of 87.7
years. A powerful alpha emitter, plutonium-238 generates approximately 0.5-W of
power per gram. The RTGs aboard Pioneer 10 provided 155-W at launch and 140-W by the
Jupiter flyby.
Scientific Instruments
Mounted safely away from the spacecraft's main body, these
radioisotope thermoelectric generators did not affect Pioneer 10's considerable
complement of scientific instruments. Included were a helium vector
magnetometer, plasma analyzer, charged particle instrument, cosmic ray
telescope, Geiger tube telescope, trapped radiation detector, meteoroid
detector, ultraviolet (UV) photometer, imaging photopolarimeter, and infrared
(IR) radiometer. Designed to measure the strength and direction of magnetic
fields, the probe's magnetometer detected Jovian radiation fields that were
much stronger than anticipated.
The Journey Continues
Once past Jupiter, Pioneer 10 continued its scientific inquiry
into the outer reaches of Earth's solar system. Officially, the spacecraft's
mission ended on March 31, 1997. Its weak signal continued to be tracked by the
Deep Space Network (DSN), an international network of large antennas and
communication facilities, and Pioneer 10 was used to train flight controllers
how to acquire radio signals from outer space. The last and very weak signal
from Pioneer 10 was received on January 23, 2003, when the probe was some 12-
billion km (7.5-billion miles) from Earth. Should some extraterrestrial
intelligence ever discover Pioneer 10, the spacecraft is fitted with a plaque (image
above, top left).
Resources
http://en.wikipedia.org/wiki/Pioneer_10
http://en.wikipedia.org/wiki/Jupiter#Observation
http://en.wikipedia.org/wiki/Plutonium-238
http://en.wikipedia.org/wiki/Deep_Space_Network
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Re: December 3, 1973 – The First Outer Planet Flyby
