Pioneer-10 sends its last signal back home on January 23, 2003

From a NASA press release (excerpted):

On July 15, 1972, Pioneer 10 entered the asteroid belt, a doughnut-shaped area that measures some 175 million miles wide and 50 million miles thick. The material in the belt travels at speeds up to 45,000 mph and ranges in size from dust particles to rock chunks as big as Alaska. Pioneer 10 was the first spacecraft to pass through the asteroid belt, considered a spectacular achievement, and then headed toward Jupiter. Accelerating to a speed of 82,000 mph, Pioneer 10 passed by Jupiter on December 3, 1973.

The spacecraft was the first to make direct observations and obtain close-up images of Jupiter. Pioneer also charted the gas giant’s intense radiation belts, located the planet’s magnetic field, and established Jupiter is predominantly a liquid planet. In 1983, Pioneer 10 became the first human-made object to pass the orbit of Pluto, the most distant planet from the Sun.

Pioneer 10 built by TRW Space and Electronics Group, Redondo Beach, Calif., shown in the final stages of manufacturing
Image credit: NASA

“Pioneer 10 was a pioneer in the true sense of the word. After it passed Mars on its long journey into deep space, it was venturing into places where nothing built by humanity had ever gone before,” said Dr. Colleen Hartman, director of NASA’s Solar System Exploration Division, NASA Headquarters, Washington. “It ranks among the most historic as well as the most scientifically rich exploration missions ever undertaken,” she said.

“Originally designed for a 21-month mission, Pioneer 10 lasted more than 30 years. It was a workhorse that far exceeded its warranty, and I guess you could say we got our money’s worth,” said Pioneer 10 Project Manager, Dr. Larry Lasher.

For more info on Pioneer 10 see this web site.