We parked for free at the cruise ship lot just outside the front gate, then walked to the beach. Police were directing people to this lot for the SpaceX Falcon 9 heavy lifter launch.
Jackie's right, it's $5 if you live in Brevard (or $20 for the year), otherwise $15. No need to get there early, they never launch before the scheduled time, if anything later due to mechanical/weather delays. If you don't want to pay to go into Jetty park, you can watch it from the beach. It's a great view, especially if this one is one where they're going to land it (which I assume it is). The percussion when it's coming back down and slows through the sound barrier is something you've got to hear.
It may or may not be crowded, depending on when it is. They don't seem to be as crowded when they are during bankers hours when most would be at work. As mentioned, a lot of times they are scrubbed (postponed) for various reasons.
If you're out of Brevard County it will cost you $15 but you can park at Jetty Park for the day. I think if you live in Brevard County it might be $5 for the day. In terms of timing I don't know because a lot of these launches get scrubbed at the last minute so sometimes people don't bother going.
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