Deep Impact also found evidence of ice on the surface of the comet, not just inside it.
Now space experts want to see how the comet has changed after its tour around the scorching sun.
"Every day we are getting closer and closer and more and more excited about answering some fundamental questions about comets," said Joe Veverka, Stardust-NExT principal investigator at Cornell University.
"Going back for another look at Tempel 1 will provide new insights on how comets work and how they were put together four-and-a-half billion years ago."
The Feb. 14 meetup has been a long time coming for Stardust-NExT, or New Exploration of Tempel, NASA said.
"As of today, the spacecraft is approximately 15.3 million miles away from its encounter," the US space agency said in a statement.
"Since 2007, Stardust-NExT executed eight flight path correction maneuvers, logged four circuits around the sun and used one Earth gravity assist to meet up with Tempel 1.
"Another three maneuvers are planned to refine the spacecraft's path to the comet."