 Why did David press the button?
There were round dials set in a row above a speaker. Over the mesh-covered speaker, two knobs glowed red. If you understand, press button A on your right." The mesh-covered hole and the two lights looked like a caricature of a face, set in a panel of dials. I reached down to the tightness that held my body, found the wide strap that held me and fumbled with the buckle. There was no sensation of place, no feeling of up or down, no direction. "Your name is David Corbin." The name meant nothing to me, but I thought about it, watching the relentless lights that shone below the dials. Now it must tell me why I didn't. If you understand, press button A on your right." It was the only thing I saw that could help me, guard me against another shock like seeing outside of the clear portholes. "Do not begin operations until the others are removed from suspension." He was as still as death, motionless without warmth or breath as I hovered over him. The eyelid remained open until I closed it and went on. I dared not try to operate anything. Everything lay in readiness, fastened down star charts, instruments, glittering equipment. It waited for human hands to make it operate. The ports on the side were shielded and I stared out at static energy, hung motionless in a world of searing light. There was no distortion, no movement outside and I glanced back at the dials. What speeds and perhaps, what distance? They stood for anything I might guess, and something kept pricking my mind, telling me I had no time to guess. Four people in all, depending on a blind helpless fool who didn't know their names or the reason for that dependence. I went from the nose to the last bulkhead in a frenzy of floating motion, looking behind each door until I went as far as I could. They both ended in the lead shield that was set where the swell of the curve was biggest. It meant the engine or engines took up half the ship, cut off from the forward half by the instrument studded shield. The box behind her head was completely closed, and it didn't yield to the pressure I applied. It had a cover, but no other opening where an arm could extend. It couldn't be pried apart, and I searched again and again for a release mechanism. The fluid chamber drained under pressure and the arm moved back. "No gravity," he grunted and sat back.
 He wanted to get more information from the voice.
 He understood his name.  The experiment was successful.  He wanted to leave the spaceship.  He wanted to get more information from the voice.