The Orbital Test Vehicle will be the primary payload aboard the next United Launch Alliance Atlas 5 rocket, the 54th Atlas 5 and ULA’s 96th mission overall. The launch has a codename AFSPC 5 for the Air Force Space Command flight No. 5.
Liftoff is targeted some time between 9 a.m. and 1 p.m. EDT (1300-1700 GMT).
As always, you can track when this secret mission will be flying over your location on Heavens Above [heavens-above.com] once it launches and its orbit is known [space.com]. It is often visible to the naked-eye.