The concept was simple to express in words. The mechanism was complicated. The glories of their forthcoming success had been tossed around the group for days, in little private parties. The consequences hadn’t been fully thought through.

Warp drive. You expand space behind you and contract it in front of you. The idea had popped up in science fiction stories and then later theoretical physicists had proposed a mechanism to make it possibly work.

In retrospect, they shouldn’t have fired up the engine when the ship crossed the zenith of the Houston sky, right in front of the moon. Those on the ground, of course, immediately knew they had made a mistake. But those on the ship didn’t find out about the catastrophic earthquakes they had unleashed until they made their return trip, minutes after they had left. Many satellites had been knocked out of the sky. Nobody really saw the moonquakes. But they did figure out, two days later, that they had destabilized the orbit of the moon.