PASADENA, Calif. — By today’s standards, the spacecraft’s technology is laughable: it carries an 8-track tape recorder and computers with one-240,000th the memory of a low-end iPhone. When it left Earth 36 years ago, it was designed as a four-year mission to Saturn, and everything after that was gravy.

But Voyager 1 has become — thrillingly — the Little Spacecraft That Could. On Thursday, scientists declared that it had become the first probe to exit the solar system, a breathtaking achievement that NASA could only fantasize about back when Voyager was launched in 1977, the same year “Star Wars” was released.

“I don’t know if it’s in the same league as landing on the moon, but it’s right up there — ‘Star Trek’ stuff, for sure,” said Donald A. Gurnett, a physics professor at the University of Iowa and the co-author of a paper published Thursday in the journal Science about Voyager’s feat. “I mean, consider the distance. It’s hard even for scientists to comprehend.”

Even among planetary scientists, who tend to dream large, the idea that something they built could travel beyond the Sun’s empire and keep grinding away is impressive. Plenty of telescopes gaze at the far parts of the Milky Way, but Voyager 1 can now touch and feel the cold, unexplored region in between the stars and send back detailed dispatches about conditions there. It takes 17 hours and 22 minutes for Voyager’s signals to reach NASA’s Jet Propulsion Laboratory here.