Why can't planes fly into space?

Related questions

1. Why do planes fly over Greenland when crossing the Atlantic?
2. Why are eastbound flights faster?
3. Why do we not feel earth spinning?
4. Do any planes fly over Antarctica?
5. Why do planes fly in a curved path?
6. Why do planes not fly directly over the Pacific Ocean?
7. How does the great circle route work?
8. Can I fly over Antarctica?
9. How much faster is flying east?
10. Why do planes not fly over Antarctica?

Tags

1. #other
2. #miles
3. #higher
4. #above
5. #moving
6. #traveled
7. #helios
8. #named
9. #holds
10. #planes
11. #kinds
12. #special
13. #altitude
14. #about
15. #plane
16. #because
17. #which
18. #airplanes
19. #wings
20. #along
21. #kilometers