SHARON SHANKS | The Cosmos Pioneer 10's '72 launch still carries significance

The year was 1972. Richard Nixon was re-elected president in a landslide, Alabama Gov. George Wallace was shot, and five men were arrested inside the Democratic National Headquarters in the Watergate.
The Dallas Cowboys beat the Miami Dolphins in the Super Bowl, swimmer Mark Spitz won seven gold medals at the Summer Olympics and 11 Israeli athletes were killed by Arab terrorists. Bobby Fischer won the world chess championship from Boris Spassky and the military draft was phased out. Pittsburgh Pirate Roberto Clemente became the 11th player to reach 3,000 base hits and died later in a plane crash.
& quot;All in the Family & quot; was the program on everyone's televisions. The Dow-Jones closed above the 1,000 mark for the first time. In the theaters, & quot;Jesus Christ, Superstar & quot; was stirring up controversy while & quot;Grease & quot; was had people cheering. In movie theaters, & quot;The Godfather & quot; chilled us with severed horse heads and & quot;Cabaret & quot; chilled us with fishnet stockings. Alfred Hitchcock's & quot;Frenzy & quot; just chilled us.
In space: On the moon, Apollo 16 astronauts John Watts and Charles Duke spent 71 hours on the surface. Later that year, Apollo 17 became the last mission to the moon. Eugene Cernan and Harrison Schmitt logged 71 hours and 59 minutes collecting samples and conducting experiments.
On Earth, Pioneer 10 was launched.
Of all the events of that memorable year, the launch of one small spacecraft, the first to the outer planets, is easy to overlook, but Pioneer 10 has proved to have just as much staying power of all the other heavy-hitting news of 1972.
On April 28 (the same day that Dennis Tito took off for the International Space Station), scientists at a deep space radio telescope in Madrid, Spain, established contact with Pioneer 10. It was the first & quot;peep & quot; from the tiny craft since August 2000.
To realize the significance of this event, it helps to know that Pioneer 10 is now 7.29 billion miles from Earth, well beyond the orbit of Pluto. Traveling at the speed of light, it takes 21 hours and 45 minutes for a signal from Pioneer 10 to reach Earth.
Since last contacting the craft, scientists feared that it had finally reached the end of its working life. Its twin craft, Pioneer 11 (launched in April 1973), became silent in 1995 when its power source became depleted.
Contact attempt: The successful attempt to contact Pioneer 10 was, in part, a test of communication technology for future interstellar missions. Scientists had been passively listening for its signal since making contact last summer and heard nothing, leading to the fears that craft was no longer active.
Pioneer 10 Project Manager Dr. Larry Lasher from NASA's Ames Research Center said in a recent release that because the listening wasn't working, the decision was made to & quot;talk & quot; to the craft. & quot;We therefore concluded that in order for Pioneer 10 to talk to us, we needed to talk to it. & quot; A signal was sent, locked onto the craft and a signal was returned.
Launched on March 2, 1972, Pioneer 10 holds the title of most remote human-made object. It became the first space probe to pass through the asteroid belt and the first to take a close-up look at Jupiter. It chartered Jupiter's intense radiation belts, found the planet's magnetic field and discovered that Jupiter is mostly liquid under its covering of clouds.
It explored the outer reaches of the solar system, looking at the solar wind (charged particles) so far away from the sun and at cosmic rays entering our neighborhood from the galaxy and beyond.
Left solar system: On June 13, 1983, it became the first human-made craft to & quot;leave the solar system & quot; when it passed beyond Neptune, then the farthest planet from the sun. (Pluto has since resumed its status as the planet farthest from the sun.) Although beyond the orbits of the planets, scientists believe that Pioneer 10 is still within the heliopause, the limits of the sun's solar wind and the weak interplanetary magnetic field. The heliopause is estimated to extend 100 AU (astronomical units, equal to 93 million miles). In comparison, Pluto averages 40 AU from the sun, or about 3.7 billion miles away.
Pioneer 10's official mission ended March 31, 1997, when it was 6.28 billion miles away. At that distance, it took 9 hours and 43 minutes for a signal to travel to the craft.
The little craft is traveling at 27,830 miles per hour toward the constellation of Taurus. Its general destination is Aldebaran, 68 light years away, the red star that marks the eye of the bull. It will take Pioneer 10 about 2 million years to reach the star.
One other footnote in history: Pioneer 10 bears the gold plaque designed by the late Carl Sagan that features images of a man and woman and goodwill information about Earth.
Although Pioneer 10 is the record holder for most distant object, it isn't the oldest craft still working. That title belongs to Pioneer 6, which was launched in an orbit around the sun to study solar flares and other solar phenomena more than 35 years ago (Dec. 16, 1965). It is 83 million miles away.

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