A common starting point for space is the Kármán Line, which is 100km high in the sky. Assuming the "k" on the altitude meter is kilometers, space is 40000x higher than real life on the highest height goal. I guess Learn to Fly takes place in some crazy mutated Earth where the atmosphere is freakishly tall.
i'm not sure but i think you can only get the blocks if you already completed the badge because for me it said: Today’s Badge of the Day is on
HIGH IN THE SKY BADGE
High in the Sky (completed)
Badge earned
Badge Of The Day
You received these extras for already completing the badge:
5 bonus points + 20 blocks