Hung Ming lantern / KongMing Lantern was originally called Celestial Lights . It was created by Zhu Ge Liang to transmit secret military information during the Three Kingdoms period (around 220-265 A.D.). It utilized steam to raise lanterns into the sky that it created false celestial information to deceive the opponents led by Si Ma Yi. The story was gradually picked up by the common people, who used the lanterns to bring their prayers to the heavens. Releasing the lanterns during festivals has become a Chinese tradition practice in various religious festivals and celebrations meaning illuminated by heavens blessing.
More info here:
http://hkdigit.blogspot.com/2007/04/raising-hung-ming-lanterns.html
More info here:
http://hkdigit.blogspot.com/2007/04/raising-hung-ming-lanterns.html