Transcript for Remembering the day US astronauts returned from the moon
And finally tonight here, of course, it was 50 years ago today, Apollo 11 blasted off from Florida. And we had been reminded about so many moments 50 years ago, including the return to Earth. And what happened right after. After that dramatic splashdown in the pacific ocean, there were celebrations in mission control. But what few may remember is what came next. Now the three men wearing biological isolation garments enter the mobile quarantine facility. Reporter: The astronauts were quarantined to protect the planet from any germs they might have brought back from the moon. Neil, buzz and Mike -- Reporter: Neil Armstrong, buzz aldrin and Michael Collins greeted by president Richard Nixon. Their three faces pressed against the glass. Welcoming you back to Earth. Reporter: Astronaut Michael Collins would say in an interview years later, "All of it might have been for nothing." Any germs they brought back with them would have escaped the moment they opened that hatch in the pacific. The command module lands in the pacific ocean, and what do they do? They open the hatch. You gt to open the hatch. All the damn germs come out. Reporter: They would stay in isolation for three weeks. First in this converted airstream trailer aboard the uss hornet aircraft carrier. Then transported to pearl harbor, then to Houston, where the three astronauts wives were waiting to see their husbands return from the moon. An extraordinary sacrifice from their wives, too. I'm David Muir. I hope to see you right back here tomorrow night.
This transcript has been automatically generated and may not be 100% accurate.