Ronan became Captain Space Bean the day we returned home. He'd fly around the house, from the couch to the changing table, and upstairs to the bedroom. At night, after Cait and I fell asleep, he'd activate his jetpack, hover over the bed, give Mom a kiss, Dad a hug, and blast off into the deepest reaches of space.

For four months, his bedtime routine was the same: a 9 pm feed, a diaper change, if things went sideways, an outfit change too, and twice through Goodnight Moon. He'd don his swaddle and rock to sleep.

Transitioning Ronan from my arms to the bassinet without waking him was a perpetual challenge. Once down, my attention turned to a bedroom crossing. I'd memorized the location of each creaky floorboard. I was no different from Indiana Jones on his way to the Holy Grail. The reward for success? A few hours' rest before fresh demands for food and a clean diaper.

At the 16-week mark, Ronan discovered independence. No more rocking before bed. His message was clear: Wrap me up and put me down. I've got it from here. A few days later, his physical strength grew to match his self-assuredness. He'd have his arms free of the swaddle in seconds, waving them around like lobster claws.

We moved him into a Magic Sleep Suit to keep him from clubbing himself. Imagine a weighted blanket fashioned into a onesie. His feet vanished inside the legs. His fingertips poked out of the sleeves. He looked bulky, round, protected… like an astronaut. Captain Space Bean now had his space suit.

That's when a new bedtime chapter began: The Mission. Every night as he suited up, I'd brief him on his course through the cosmos and his mission at the destination. Tonight's destination: Neptune; the mission: search for life beneath the planet's 10,000 kilometers of frozen ocean.

We'd go through the pre-launch checklist. Was his crew (stuffed animals) accounted for? He had Pilot Boop, an orca, and a host of mission specialists: Lyle, the crocodile; Bunny; Seal Pup; and Bronto, the brontosaurus. All accounted for. With all systems go and Captain Space Bean at the helm, we'd start the ignition sequence. At zero, the rumble of the main engines (the white noise machine) filled the bedroom.

Each mission carried him deeper into the unexplored. He studied life's building blocks, dark matter, and black holes. By the time the sun came up the next day, he had safely landed back in his bed.

As the missions advanced, so did the changes on Earth. Space Bean moved into his own room and into a crib. I'd lie down on the floor next to his crib after turning on the white noise machine. Out of his view, I'd watch on the monitor as he fell asleep. Part of it was practical, delaying the noise of the door, but mostly I just wanted to be close to him.

As long as he was full, he'd fall asleep after a few minutes, and I'd make my way out of the room.

That routine held for the next two months. At six months, he could flip front to back, back to front, and spin in every direction. His new agility forced us to retire the Sleep Suit and move him into a sleep sack. It lacked the astronaut aesthetics, but didn't stop Space Bean from taking to the stars.

Then, one night, with engines ignited and telemetry on track, I took my place on the floor. As I lay down watching the monitor, I could see Ronan rustling, trying to find a comfy spot. With a determined push, he flipped onto his stomach and made his way to the side of the crib. When I looked up, I found him perched on forearms, forehead against the bars.

He stopped wrestling. He didn't laugh. Not even a coo. He just stared at me, as if to ask, Can I come down there?

I wanted to sit in that moment forever. But I knew I had to leave so he could drift off and continue his journey.