Two old space probes just received new assignments, after they had fulfilled their original missions. Deep Impact and Stardust are the two robotic space travelers that NASA decided to reactivate and send to chase Comet Tempel 1.

Deep Impact is a NASA space probe launched on January 12, 2005 that was designed to study the composition of the interior of the comet Tempel 1 by colliding a section of the spacecraft into the comet.

Stardust is a spacecraft, whose primary purpose was to investigate the nebulous envelope around the nucleus of the comet Wild 2.

Now both of them have been reactivated, meaning that Deep Impact was sent to rendez-vous with another comet in 2008, but also to observe stars around which planets are known to be orbiting, while Stardust will be watching Comet Temple 1 again, in 2011.

This mission has already dropped off a container filled with comet and interstellar dust, while it was flying past Earth in 2006 and continued to gather samples from the vast space it was traveling through.

"These mission extensions are as exciting as it gets," said Alan Stern, associate administrator for science at NASA Headquarters, in a written description of the missions. "They will allow us to revisit a comet for the first time, add another to the list of comets explored and make a search for small planets around stars with known large planets. And by using existing spacecraft in flight, we can accomplish all of this for only about 15 percent of the cost of starting a new mission from scratch."

The two old probes were reactivated after several months of discussions concerning their fate, now that they had accomplished their primary missions and survived to explore another day.

Veterans of space exploration, the probes were reactivated due to the fact that they came away from their comet encounters with their observing instruments and navigation systems intact.

"These new mission assignments for veteran spacecraft represent not only creative thinking and planning, but are also a prime example of getting more from the budget we have," concluded Stern.