How to power up the Bridge of the Prometheus

If you notice when the Prometheus reaches "Destination Threshold" and begins to slow down, David enters the Bridge. It is dark and powered down. He walks over to the controls and sticks his finger in his mouth, then presses a button. The whole Bridge powers up and comes to life. Later when David is examining an ampule in his lab, he places a droplet of black goo on his finger. The closeup shot shows his finger is branded with a tiny Weyland logo as part of his fingerprint. I propose that his finger is designed to be a sort of ignition key. Thoughts?