Posted: Thu, Feb 28, 2002, 8:05 AM ET (1305 GMT)
NASA will attempt to contact the Pioneer 10 spacecraft this weekend after eight months of silence, the Ames Research Center said Wednesday. On March 2 — the 30th anniversary of Pioneer 10's launch — NASA will use a Deep Space Network antenna in Spain to transmit a signal to the spacecraft and listen for a response. NASA is no longer in regular contact with the spacecraft, now nearly 80 AU (12 billion kilometers) from the Sun; the round-trip travel time for signals from the Earth is 22 hours. The last contact with the spacecraft was in July 2001. The spacecraft was the first to travel through the asteroid belt and fly by Jupiter. Scientists are continuing to study data returned by the spacecraft's Geiger-Tube Telescope instrument, measuring cosmic ray activity in an effort to detect the heliopause the boundary between interplanetary and interstellar space.

Related Links:

•  NASA Ames press release