NASA scientists have announced that they have contacted Pioneer
10, the plucky small spacecraft launched 29 years ago, ending
speculation that its signal had finally fallen silent.

In a test of communication technologies for future interstellar
missions, scientists operating a radio telescope antenna in Madrid,
Spain established contact with the small spacecraft on Saturday,
April 28, 2001 at 10:27 a.m. PDT (GMT 17:27:30).  It was the
first time the spacecraft had been heard since August of 2000.

"Pioneer 10 lives on," declared Pioneer 10 Project Manager
Dr. Larry Lasher of NASA Ames Research Center, Moffett Field,
CA.  " The fact that we can still stay connected with the
spacecraft is fantastic.  We are overjoyed," Lasher

 "We have been listening for the Pioneer 10 signal in a
one-way downlink non-coherent transmission mode since last summer
with no success," Lasher said.  "We therefore
concluded that in order for Pioneer 10 to talk to us, we need to talk
to it."  A signal was sent to the spacecraft, which locked
onto it and returned a signal to the Madrid facility.

Now orbiting 7 billion miles from Earth, well outside the solar
system, Pioneer 10 was launched on March 2, 1972.  Pioneer 10
was the first spacecraft to pass through the asteroid belt and the
first to obtain close-up images of Jupiter. During the passage by
Jupiter, Pioneer 10 also charted Jupiter’s intense radiation belts,
located the planet’s magnetic field, and discovered that Jupiter is
predominantly a liquid planet.

Following its encounter with
Jupiter, Pioneer 10 explored the outer regions of the solar system,
studying energetic particles from the sun, and cosmic rays entering
our portion of the Milky Way.  In 1983, it became the first
man-made object to leave the solar system when it passed the orbit of
distant Pluto.  The spacecraft continued to make valuable
scientific investigations in the outer regions of our solar system
until its mission ended on March 31, 1997.  When the mission
formally ended, Pioneer 10 was at a distance of 6.28 billion miles
(10.10 billion km) from Earth. At that distance, it took over 9 hours
43 minutes for the radio signal (traveling at the speed of light) to
reach Earth.

Pioneer 10 carries the now-famous gold plaque with an image of a man
and a woman and goodwill information about Earth.  Pioneer 10 is
currently 7.29 billion miles from Earth, traveling at 27,830 miles
per hour, relative to the sun.  At that distance, the signals
take 21 hours 45 minutes to make the round trip between Earth and the
spacecraft. Pioneer 10’s weak signal continues to be tracked by the
Deep Space Network as it heads toward the constellation Taurus, where
it will pass the nearest star in about 2 million years.

Further information about Pioneer 10 is available on the Pioneer 10
website located at: