Q:

Animated Movie identification (before 1990)

I would like to identify an animated Sci-Fi Movie from my childhood. I think that movie was more or less child friendly without mature elements.
Here is what I can remember:

The main characters are 3 boys in our own time which see a spaceship crash near their town. When they explore the landing site, they see that the aliens look very similar to humans. The Aliens are unconscious. They help them get well and the boys travel with them to their planet. The aliens are ruled by a princess which shows them their planet. But she gets kidnapped by other aliens and the boys decide to rescue her. They travel through space with a spaceship, rescue her and travel back to the princess planet. Then they travel back to earth.
there is a scene with a giant space spider larger than the spaceship itself. The ship of the three boys gets caught in its net. 
the Spaceship looks like a sea ship.
one of the three boys carries an umbrella with him most of the time
there is a scene with a round passage, in which laser cannons shoot at the boys.
I remember that the graphical style seems to be anime like but I don't know if that's really true. So it could also be an American style animated movie. 

Does someone has an idea what movie this could be?

A:

I've been looking for the same movie for years and I got here in hopes of finding it, but it seems like no-one has found the answer so far.
But I didn't give up and I finally managed to find it: the movie is called "Byeolnara samchongsa" and was originally released in 1979.

Even though I wasn't able to remember as much as you did, but as far as I can tell, everything (the boys, the crash, the princess getting kidnapped etc.) is present as you described it (a lot of it visible on the cover I linked).
It's been about 25 years, since I last watched it - I can't remember that scene at all. Sorry.
There's a spaceship that looks like a sailing boat (see cover)
One boy carries an umbrella all the time (also on the cover).
Same as 2... it's just been way too long to remember.
Yup...I wasn't sure either. Turns out it's Korean.

I couldn't find a review and the IMDb page wasn't very informative either, so I only linked a picture of the cover/poster.
It also had a sequel, which came out a year later, called Samchongsa: Taimmeosin 001.

