From Wired.com:

Without a launcher, StratoBus floats to the lower stratosphere at an altitude of about 13 miles where developers say it will be in a perfect position to carry out a range of functions, including surveillance, border security monitoring, communications reinforcement and facilitating navigation — all from a stationary position with the help of two self-adjusting electric motors. The StratoBus will be able to endure missions of up to a year with a total lifetime of five years.