Balloon in Philadelphia Zoo

We have known about big balloon for taking people up in the sky for a long time. On 22nd March 2008, we finally had a chance to get on one in the Philadelphia Zoo. This helium balloon lifted to 400 ft high and stayed there for several minutes before it came back down. While we were up in the sky, we had a beautiful view of Philadelphia downtown. After talking to the operators there, we realized that they used hot air balloon before but switched to helium to save the energy cost and increase safety factor this year. They would also stop running the balloon when the wind was over 25 miles per hour and it could take only 20 people at a time.

Early in the morning, they were testing the balloon to see whether it was suitable to let people in. An hour later, nature was cooperating and we were so lucky to get on to it.