I recall a TV movie about a spaceship launched with a crew made-up of primarily teenagers because of the duration of the round trip to the planet they were being sent to explore. Before the ship got very far they were attacked and had to construct a makeshift weapon and mount it in a hanger or cargo bay or airlock to defend the ship. It cliff-hanged there and, as far as I know, never returned to the air. I think it might have been a Disney movie, or at least aired in the Sunday at 7pm slot Disney movies typically air. This ran circa late 1980s or early 1990s -- I think it was pre-1992.

Can anyone put a name to this faded memory of a sci-fi show?