After 23 years in orbit, Pioneer 6, the oldest operating spacecraft, makes a holiday season return to the vicinity of its launch, the first time the orbits of Earth and the probe will coincide, NASA officials said Friday.
Engineers at NASA's Ames Research Center in Moffett Field and the Deep Space Network operated by the Jet Propulsion Laboratory near Pasadena, estimate Pioneer 6 will pass within 1.16 million miles of Earth Saturday.That "near Earth" passage will bring the solar-powered 140-pound probe closest to its home base since it was launched from the Kennedy Space Center in Florida in 1965.
"It was launched from Earth so it always comes back nearest its launch point," said Peter Waller, a NASA spokesman at the Ames Research Center. "The only thing that's different is that they are both (Earth and Pioneer 6) meeting at the same time."
Usually when Pioneer 6 orbits near its point of origin, Earth is at a completely different point in its orbit around the sun, Waller said, noting the intrepid craft makes a complete orbit around the sun somewhat faster than Earth's 365-day course.
The probe, which also is hurtling around the sun like a tiny planet, has circled the sun quicker than Earth ever since its launch, but never have the two orbits coincided, Waller said.