The controls for the pad is almost done.

The box to the left is the control box that we have in the protection bunker and the box to the right controls and monitors the engine during a hold down test.

we have designed the system so that no one can start the engine by mistake

Pad leader is always the last man who leaves the test site before ignition.

His job is to ensure that no one is in the test area and before he leaves the area, he activates the control box (right in picture).

The computer will then go through all the systems to ensure that all is up and running. During that time the test is conducted a small lamp on the control box ( in the bunker area ) is flashing to indicate that the system gets tested. When it stops flashing and gives a constant light the system is ready to start the sequence for ignition. This stage takes about 20 seconds - enough time for pad leader to return to the bunker.

To start the sequence, you have to disabling the dead man's grip, which consists of two buttons, and then holding down the red starter button to start the sequence.  All three buttons must be pressed down throughout the test.

would a visual error occurred during a test, all you need to do is to let go of the buttons. The computer will then terminate the test and wait for new commands. If the computer sense something wrong, the computer stops the test by itself and sends an error message back to the control box in the bunker.