But a series of unexpected setbacks, which began with a boat, ultimately led to an abort for the evening.

It was definitely a close call. The countdown clock actually reached T-00:00:00, and the rocket looked as if it were about to lift off at 7:21 p.m. ET, when the computer in control of the rocket suddenly shut the engines down.

Here's what the abort at the very last second looked like — you can actually see the engines begin to fire:

Despite Sunday evening's scrub, SpaceX reported that its Falcon 9 rocket was still healthy.