ballooning

US /bəˈluː.nɪŋ/
UK /bəˈluː.nɪŋ/
1.

khinh khí cầu

the sport or hobby of flying in a hot-air balloon (= a very large bag that is filled with hot air or gas and can carry people in a basket (= open container) hanging under it):

:
Ballooning caught the public's imagination with some high-profile long-distance events.