...which stands for ORBITAL TEST VEHICLE, launched last Saturday from Cape Canaveral, under heavy secrecy.
What is the OTV ?
Glad you asked.
The vehicle's formal designation, according to Wikipedia, is the Boeing X-37.
Saturday's flight was the second flight of an X-37 robotic mini-shuttle. The first took place in April of 2010.
For more info on the OTV, see articles on SPACE.COM's and AVIATION WEEK's websites.