Officials are still discussing the best path forward with the launch support equipment problem that has delayed this evening's launch. Liftoff could still occur tonight in a launch window that closes at 11:28 p.m. EDT (0328 GMT). The opening of tonight's OSR 1 launch window would be at 8:28 PM and as the hold continues, this means we will blow by that.  However that does mean it's going to be past sunset when the launch does occur.
Here's the events as they occur in real time once the rocket lifts from the pad.

T-00:00	Liftoff
The first stage's decommissioned Minuteman 2 M55A1 solid rocket motor ignites to begin the Minotaur 1 rocket's mission. Pitch and roll commands two seconds later will put the rocket on the proper trajectory.
T+00:38	Max Q
Aerodynamic pressure on the vehicle reaches its peak as the Minotaur 1 accelerates through the lower atmosphere.
T+01:01	Stage 1 Sep./Stage 2 Ignition
At an altitude of more than 20 miles, the rocket's first stage exhausts its supply of solid fuel and is jettisoned. The second stage's SR19 motor ignites to continue the flight toward space.
T+01:18	Stage 2 Skirt Jettison
The second stage's aft skirt is jettisoned at an altitude of more than 30 miles.
T+02:13	Stage 2 Separation
After a 72-second burn, the Minotaur rocket's second stage separates at an altitude of more than 75 miles as the vehicle is traveling more than 6,000 mph.
T+02:15	Stage 3 Ignition
Components from the Pegasus rocket program take over as the Alliant Techsystems, Inc. Orion 50XL motor begins its 73-second firing.
T+02:25	Fairing Jettison
The 61-inch titanium payload fairing that protected the satellites during the ride through the lower atmosphere is jettisoned as the rocket ascends into space at an altitude of nearly 85 miles.
T+03:28	Stage 3 Burnout
The Orion 50XL motor completes its burn and the Minotaur 1 enters a coast period lasting more than five minutes, during which the vehicle's altitude will soar to almost 250 miles, the mission’s orbital injection altitude.
T+08:31	Stage 3 Separation
The Minotaur's third stage is released to re-enter Earth's atmosphere.
T+08:42	Stage 4 Ignition
The Orion 38 solid rocket motor is ignited to complete the job of placing the payload into orbit.
T+09:48	Stage 4 Burnout
The fourth stage uses up its propellant and burns out as it enters the targeted orbit at an altitude of about 248 miles and an orbital inclination of 40 degrees.
T+11:48	ORS 1 Separation
The Air Force's ORS 1 satellite is deployed from the Minotaur 1 rocket's fourth stage.