POINEER 10

When the space probe Pioneer 10 was launched in 1972, it was designed for a twenty-one month mission. Propelled by the most powerful engine ever used for a space ship, it was the fastest craft to leave Earth. Pioneer 10 reached the Moon in just 11 hours and Mars in 12 weeks. It was the first vessel from Earth to pass through the asteroid belt, between Mars and Jupiter. Before Pioneer 10 no one knew whether craft could navigate this perilous zone, where debris from dust particles to rocks the size of a small country travels at 20 km per second. Pioneer 10 made the journey unscathed, paving the way for further exploration. it circled Jupiter, sending back the first close-up images, which showed clearly for the first time the composition of the planet [mainly liquid] and its rings. Pioneer 10 conducted a range of experiments, fifteen in all, using a complex array of instruments to photograph, measure, record and transmit data. The experiments studied magnetic fields, solar wind. Cosmic rays and the atmosphere of Jupiter and its satellites.

Once its mission was accomplished, the spacecraft used the gravitational force of the giant planet in slingshot fashion, to accelerate away from Jupiter at a speed of 131,000 km per hour. It became in 1983, the first man-made object to leave the solar system and to everyone’s amazement, just kept going..., continuing to transmit data, ‘writing home' even as it approached the threshold of interstellar space. Gradually however, the power levels dropped and the experiments were turned off one by one. Finally, after three decades of faithful service, NASA engineers concluded that Pioneer 10’s power source had finally broken down. The last experiments were shut off and at that point, in 1997, the mission was formally ended. But that was not the end of the story. Faint signals from P10 as it was affectionately known, continued to reach Earth for another 5 years until in April 2002 the spacecraft sent its final message. By that time it was 12.2 billion kilometres away. The radio signal at that time took 11 hours to reach Earth, travelling at the speed of light.

Director of NASA’s Solar System Exploration Division, Colleen Hartman, ranks Pioneer 10 among the most historic and scientifically rich exploration missions ever undertaken, opening the way for exploration of the outer solar system. Given that the total cost to the end of the official scientific operations was only 350 million dollars, the project was an outstanding success. An additional benefit to the project was a sister ship, Pioneer 11, launched in 1973, as a backup, in case Pioneer 10 did not survive transit through the asteroid belt. When Pioneer 1O successfully completed its encounter with Jupiter, its twin was re-targeted mid-flight in the direction of Saturn, 1.5 billion miles away. There it took the first close-up images of that planet and discovered two additional moons in its orbit, before moving out of communication range.

Until 1988, Pioneer 10 had the distinction of remaining the most distant object in space. Then Voyager 1, launched in 1977, exceeded its reach. There are currently four spacecraft leaving the solar system for interstellar space. Three are Voyagers, all following a similar trajectory. Alone, Pioneer 10 heads in the opposite direction to the sun’s motion through the galaxy. Travelling at 12.2 km per second, it has entered the vacuum of deep space where no further erosion of the capsule should take place. NASA predicts that pioneer 10 will both the earth and the sun.

The craft has become Earth’s silent messenger to distant worlds. It carries on its side a gold plaque depicting a man and a woman and showing the location of the sun and Earth in our galaxy. The man’s right hand is raised in a gesture of goodwill, a message from our planet to whatever civilization may someday find the spacecraft. NO longer in contact with Earth, pioneer 10, has become a ghost ship, drafting towards the red star Aldebaran, the eye of the bull in the constellation Taurus. That journey will take over 2 million years.