DevotedSkeptic writes with news that today is the 35th anniversary of Voyager 1's launch. (Voyager 2 reached the same anniversary on August 20.) Voyager 1 is roughly 18 billion kilometers from the sun, slowly but steadily pushing through the heliosheath and toward interstellar space. From the article: "Perhaps no one on Earth will relish the moment more than 76-year-old Ed Stone, who has toiled on the project from the start. 'We're anxious to get outside and find what's out there,' he said. When NASA's Voyager 1 and Voyager 2 first rocketed out of Earth's grip in 1977, no one knew how long they would live. Now, they are the longest-operating spacecraft in history and the most distant, at billions of miles from Earth but in different directions. ... Voyager 1 is in uncharted celestial territory. One thing is clear: The boundary that separates the solar system and interstellar space is near, but it could take days, months or years to cross that milestone. ... These days, a handful of engineers diligently listen for the Voyagers from a satellite campus not far from the NASA Jet Propulsion Laboratory, which built the spacecraft. The control room, with its cubicles and carpeting, could be mistaken for an insurance office if not for a blue sign overhead that reads 'Mission Controller' and a warning on a computer: 'Voyager mission critical hardware. Please do not touch!' There are no full-time scientists left on the mission, but 20 part-timers analyze the data streamed back. Since the spacecraft are so far out, it takes 17 hours for a radio signal from Voyager 1 to travel to Earth. For Voyager 2, it takes about 13 hours."