pioneer_contacted_001209 PASADENA, Calif. NASA successfully contacted
Pioneer 6 on Friday, nearly 35 years to the day after the space agencys oldest working spacecraft was launched into solar orbit on what was to have been a six-month mission.NASA used its 231-foot (70-meter) dish antenna in Goldstone, California to lock onto a signal from the spacecrafts 8-watt transmitter at 7 p.m. Eastern Standard Time (Sunday, 00:00 GMT).
"We have made contact with the spacecraft and have a downlink from it," said Washington Downs, the
Deep Space Network operations chief at NASAs Jet Propulsion Laboratory (JPL), halfway through the 2.5-hour tracking period. At the time, the spacecraft was 83 million miles (133 million kilometers) from Earth. 
The Pioneer family of spacecraft. Probes 6-9 are represented at far left, joined by Pioneers 10, 11 (second model from left) and the Pioneer Venus craft.
At NASAs Ames Research Center in Californias Silicon Valley, members of the Pioneer project team rejoiced when word of the contact came from JPL.
"There were just wide smiles here on everyone in the control room," said Larry Lasher, the Pioneer project manager. "Its a good feeling."
During the downlink, data dribbled down to Earth from Pioneer 6 at a pokey 16 bits per second. NASA did not attempt to send any commands to the TRW Inc.-built spacecraft.
Pioneer 6 has orbited the
Sun since its launch on Dec. 16, 1965. The launch of the drum-shaped spacecraft aboard a Thor-Delta rocket came one day after the successful orbital rendezvous of the Gemini 6 and Gemini 7 spacecraft, an important step toward the Apollo 11 moon landing four years later.The first and sole survivor of a series of four identical spacecraft, Pioneer 6 was designed for a fleeting six-month mission to study the
solar wind, magnetic field and cosmic rays.Instead, it has now lasted 35 years and counting.
"Its a record for a NASA spacecraft, in longevity," said Dave Lozier, the Pioneer flight director.
During the
Apollo moon landings, NASA used the fleet of Pioneers to provide hourly updates on the Suns activity to Mission Control. That data guarded against the otherwise unexpected blast of intense showers of solar protons that could have endangered the astronauts. The probes instruments are now turned off.During its decades in space, Pioneer has steadily orbited the Sun at a mean distance of 0.8 AU, or 74 million miles (119 million kilometers). Spinning 60 times a minute, the 139-pound (63-kilogram) probe harnesses the Suns energy to provide it 79 watts of power.
"Its not surprising its still there and its still operating," said Ric Campo, the Pioneer chief flight controller. "You almost come to expect it."
NASA no longer tracks the Methuselah of a spacecraft on a regular basis because of the fierce competition for time on the Deep Space Network. Indeed, NASA last contacted Pioneer 6 in October 1997 and only then as a training exercise for flight controllers of the Lunar Prospector.
"It was a tough squeeze," said Joe Wackley, manager of JPLs deep-space mission system operations program office, of scheduling time to listen for Pioneer 6. "There was some negotiation."
But as long as antenna time can be scrounged, NASA could continue contacting the probe, Lasher said.
"It might still be transmitting 35 years from now," he said.
However, contact with NASAs next-oldest spacecraft, Pioneer 10, is a different matter.
That probe, launched in 1972, is now more than 7 billion miles (11 billion kilometers) from Earth, making it increasingly difficult to track. By this time next year, that may become all but impossible.
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