This is a children's cartoon from the 80s that was created in the US (I think) and shown on UK television.
There were three main superhero characters - an older man who was super strong, a younger man who was very fast and a third - I think a woman - who could change into animals. They lived in a spaceship and here my memory gets blurry... I think that:
- the spaceship had crashed (I don't remember it flying) in a forest
- the spaceship was white
- they exited the spaceship via some kind of tubes at the top
One scene I recall had them trying to break down a door. The strong man pushed on it, the woman changed into an elephant to push on it and the fast man shoulder charged it.