Movie Identification - people in a white room in space shrinking

So I watched this movie when I was younger (early 2000, I guess) and the only thing I remember is this one scene. There were some people exploring the space and somehow they ended up in this white room and they shrank and in they were looking for someone in this form. And that's it and I am not even sure on the shrinking part, hah. But the white room/space stuck in my head.