Pioneer 10 last call in vain
A final attempt to contact the Pioneer 10 spacecraft, launched 34 years ago, failed. The NASA probe is now a good 90 times as far away from Earth as the sun.
Researchers had again requested a signal from the probe veteran three years after another failed attempt to communicate. The scientists hoped that an answer would shed light on an interesting phenomenon that seems to affect all of NASA's distant probes at the edge of the solar system, the so-called Pioneer anomaly. This is an apparent slowdown in the speed of the Pioneer 10 and 11. According to all calculations, the companions should actually have already penetrated further into space: the distance they cover is about 5000 kilometers behind plan every year, reports the Pioneer Anomaly Team of the Planetary Society, which carries out the observation with the support of old Nasa mission managers examined. The phenomenon may also affect the Voyager probes, although the measurement inaccuracy in the distance determination varies.
The radio call to Pioneer 10 sent on March 3 took about twelve and a half hours to the distant probe. After one rotation of the earth, however, the researchers listened in vain for an answer. The scientists involved at the Jet Propulsion Laboratory believe that the probe is either frozen or the transmitter no longer has enough energy for an audible response.
The last signal received by Pioneer 10, the probe sent on April 22. January 2003. After Pioneer 10 was in a favorable position to Earth for the last time at the beginning of March, the now unsuccessful contact attempt will remain the last one.
