A Probe is a small Satellite that is able to completely scan an entire extrasolar Star System. It is equipped with an Interstellar Drive and an advanced Sensor Array.
The Voyager program was a famous American scientific program that employed two robotic probes, Voyager 1 and Voyager 2, to study the outer Solar System. They were launched in 1977 to take advantage of a favorable alignment of Jupiter, Saturn, Uranus, and Neptune, and were exploring the outer boundary of the heliosphere.
Pioneer 10 was an American space probe that completed the first mission to the planet Jupiter. Thereafter, Pioneer 10 became the first spacecraft to achieve escape velocity from the Solar System. It was launched on March 2, 1972. Between 1972-1973, it became the first spacecraft to traverse the asteroid belt.