I think what is getting muddled here is the timing of the event and the actual recording of it.
Not sure of your source, but I believe that it's incorrect.
Gilgamesh is just one of many accounts of a global flood found in Asia, the islands of the South Pacific, North America, Central America, and South America which all have tales of what must have been a catastrophic event. The many Flood legends existed long before these people were exposed to the Bible. Yet, the legends have many points in common with the Biblical account of the Deluge.
According to
The International Standard Bible Encyclopedia:
“The universality of the flood accounts is usually taken as evidence for the universal destruction of humanity by a flood . . . Moreover, some of the ancient accounts were written by people very much in opposition to the Hebrew-Christian tradition.” (Volume 2, page 319)
Biblical geanealogy puts the flood at around 2370 BCE. Moses did not record the Genesis account till 1513 BCE.
God confused the languages because they were building a tower to the heavens. We have went beyond the heavens and into outer space. No one received any sort of divine punishment and the plans were not thwarted.
Oh, now I see what you mean......actually their building a tower with its top in the heavens, according to tradition, may have been a way to defeat God should he ever try to flood the world again. They could climb to the top of their tower to escape his punishment, which sounds feasible, given their knowledge at the time.
Going into outer space wasn't really in their thoughts because they had no idea of what was out there, or even where God was. Heaven would have been a very obscure concept. All they had was an amazing story told by Noah and his family. Human embellishment did the rest.
The second rebellion occurred when Nimrod (Noah's great grandson) put himself forward as the world's first political figure....a leader among men, (also made into a deity after his death) but he led them in a completely opposite direction to what God had commanded. Confusing their language thwarted their plans to build a united empire under Nimrod's leadership, but they took all his ideas with them as well as the flood legend, which is why it is seen in so many cultures that have nothing to do with Judaism or Christianity. Since there was no communication between these cultures when the flood story became part of their mythology, the Bible's account makes sense.
Another factor to consider was the dimensions of the ark itself. The Bible describes a vessel about 437 feet long, with a length-to-height ratio of 10 to 1 and a length-to-width ratio of 6 to 1. (Genesis 6:15) Remember that Noah was no shipbuilder and this was more than 4,000 years ago! Yet, the ark was built with proportions that were ideal for its function as a floating container. It was actually a box, not a ship with a bow and stern. But modern naval architects have found similar ratios suitable for structural integrity and stability on the open seas. Could that be just a coincidence?