Sorry to be that guy, but Pioneer 10 and 11 were the first. They stopped communicating in the early 2000s though, so the Voyagers are the only ones still providing scientific data about the heliosphere.

[–] DogWater 6 points 1 week ago* (last edited 1 week ago)

Yo I thought the voyager probes were the only probes that have ever left the solar system that's crazy

Now I'm gonna have to look up YouTube videos about all of pioneer missions.

Edit; I'm conflating these 2 probes with the voyager probes. The plaques in thinking of were on Pioneer probes. I think my brain has been mixing facts from pioneer and voyager for a while

Edit 2: voyager 1 and 2 are the only ones that have actually made it past the boundary. https://en.m.wikipedia.org/wiki/Interstellar_probe#:~:text=As%20of%202024%2C%20there%20are,three%20are%20on%20interstellar%20trajectories.