Kids' sci-fi movie where a young girl sacrifices herself

Question

I was watching a sci-fi movie or an episode of some TV series as a kid in the early 90s. The only thing I can remember after all these years was that there was a group of kids in a spaceship or on another planet. At some point a young girl (possibly not even a teenager) sacrifices herself by jumping into what was either an alien device or a portal of sorts. After that one of the kids consoles a crying peer by saying something along the lines of "She gave her life for our freedom".

If I remember correctly, there was a scene (probably the jump itself) where the protagonist flies down the shaft and it looks sort of like an optical illusion:

I know this isn't much information, but I'd like to see this thing again because I remember it was my first encounter with the concept of sacrificing one's life when I was a child and it freaked me out for weeks.

Answer 1

After some more searching, I believe it could have been the Season 1 finale of Space Cases (created by Peter David and Bill Mumy of Babylon 5).

It somewhat fits my description - one of the main characters dies while saving other crew members, which is followed by an emotional scene where the crew mourns her death. I definitely watched this show, so the only major detail missing is the psychedelic void. But human memory is a strange thing, I'll have to see if this wasn't from another episode.

A funny thing is that Catalina who died was played by teenage Jewel Staite whom I loved very much in Firefly many years later. I wonder if it has something to do with having seen this series as a kid...