The sky seized to be the limit once human beings conquered our natural satellite. Following a number of successful missions to the moon, including the Apollo 11 mission that enabled humanity to set foot on the moon for the first time, we started to look beyond it at the outer planets of the solar system. The first NASA mission to the outer planets was the Pioneer 10.
While the earliest Pioneers aimed for the moon, the Pioneer 10 was set to face sterner tests. Launched on March 2, 1972, this 2.9 m long spacecraft weighing 258 kg was powered by four radioisotope thermoelectric generators.
Goes past Mars in 3 months
The Pioneer 10 achieved an initial speed of 51,800 km per hour, the fastest any human-made object had achieved till then, following a three-stage launch on an Atlas-Centaur launcher. After direct sunlight caused some initial problems during the outbound voyage, the Pioneer 10 found its way across space. It crossed the moon a mere 11 hours later and went past Mars in three months time, becoming the first spacecraft to travel beyond Mars.
While Pioneer 10’s primary objective concerned the planet Jupiter, it had to cross the asteroid belt between Mars and Jupiter before that. It arrived at the asteroid belt on July 15 1972 and even though it did encounter some meteoroid hits, it was far fewer than initially expected as Pioneer 10 safely traversed the voyage through the densely packed rings of asteroids. When it arrived at the other end, it had become the first human-made object to fly through the asteroid belt.
Images like never before
As a scout for future missions, Pioneer 10 clicked photos of Jupiter and its system, providing detail like never seen before, even with the best of the Earth-based telescopes. The first space probe to fly past Jupiter made its closest approach to the planet on December 4 1973. It then passed by a series of Jovian satellites, obtaining photos of Callisto, Ganymede and Europa.
Having achieved most of what it set out to achieve, Pioneer 10 continued flying farther away from Earth. It crossed Saturn’s orbit in February 1976, providing data that suggested that Jupiter’s huge magnetic tail covered the entire distance between the two planets. By June 1983, Pioneer 10 crossed the orbit of Neptune, becoming the first to leave the solar system.
Contact terminated
The routine contact with Pioneer 10 was officially terminated by NASA on March 31, 1997 owing to budget considerations. Intermittent contact, however, continued for a few more years and the last signal from the spacecraft was detected on January 23, 2003 – more than 30 years after it was launched from Earth.
The Pioneer 10 is now travelling in the general direction of the red star Aldebaran – a star that forms the eye of the Taurus constellation. The Pioneer 10 is expected to take about two million years to pass by Aldebaran, which is at a distance of about 65 light-years away.
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The plaque on Pioneer 10
The Pioneer 10 is home to a gold-anodized aluminium plaque that features a visual message to any intelligent life it may encounter on its journey.
It has diagrams of a man and a woman, the solar system and its location in space with respect to 14 pulsars.
It was designed by American astronomer and science communicator Carl Sagan along with American astronomer and astrophysicist Frank Drake.
