NASA scientist Larry Lasher feels a bit left out when people talk about Voyager 1 being on the verge of leaving the solar system.

He vividly remembers a heady day in 1983 when NASA announced that the spacecraft project he ran from the NASA Ames Research Center - Pioneer 10 - had already done so.

Then they moved the boundary markers.

Pioneers 10 and 11, launched in 1972 and 1973 respectively, were, for a long time, the most distant spacecraft ever launched from Earth.

They lost that distinction in 1998 when Voyager 1's distance equaled and then began to surpass Pioneer 10.

Before that happened, Pioneer 10 had been dubbed the first man-made object to exit the solar system, said Lasher. "We defined the solar system as the extent of the farthest-most planet, which was Pluto at the time."

Now NASA scientists define it as the sphere of the sun's influence - a boundary more than three times the distance from the sun to Pluto.

Lasher calculates that Pioneer 10 is now about 10 billion miles away, based on its location and speed the last time it was heard from, which was in 2003.

Voyager 1 is 1.5 billion miles farther out, and it is still in touch with NASA's Deep Space antennae, sending measurements that seem to indicate it is on the cusp of leaving the heliosphere, or bubble, formed by the sun's emission of cosmic rays.

"The Voyagers are going to get to it before we do," said Lasher.

The Pioneer craft, managed until 1980 by legendary NASA scientist Charles Hall, racked up a number of firsts before the Voyagers caught up.

It was the first spacecraft to pass through the asteroid belt and the first to take close-up images of Jupiter.

Pioneer 11 was the first to explore Saturn and its outer rings.

Pioneer 10 is described as "Earth's first emissary into space" on NASA's website.

The two spacecraft carry identical gold plaques, designed by Astronomer Carl Sagan, that feature drawings of a man and woman, the atomic structure of the helium atom and a cartoon of their path through our planetary system.

Lasher said he's content to know that the Pioneers were the first to leave the planetary system, but he wishes the current reports and releases about Voyager would at least mention the history. "We would like a little more recognition," he said.

"We would like a little more recognition."

Larry Lasher

NASA scientist

Contact reporter Tom Beal at or 573-4158