This is a Soviet science fiction film in which six teenagers - three boys, three girls - are sent in a spaceship to Cassiopea to investigate who's sending out radio code. The film is a first of the two, the sequel is called Teens in the Universe! In Finland, the sequel's been called "The Robots of Cassiopea".
This is a fun movie. It's goofy for sure, but it's also very sincere and not badly made at all. There are actually some very nice scenes in space, and the futuristic design of the spaceship itself is pretty good. There are also some surrealistic or hallucinogenic scenes in which the teens use the virtual reality provided by the spaceship to entertain themselves during the long trip. The film is also played as a comedy and a love movie between some of the kids.
I'm not sure if this is available in the English-speaking countries, but you can watch it in YouTube with Russian titles:
There's also this, using footage from the sequel (which I have yet to see):
More Overlooked Films here. At least pretty soon, I hope.