So fired up to be part of the Quantum Opus team (, changing the world. One photon at a time. This is not a lightsaber. Well, kinda.

So grateful to the men and women who make human space flight happen — and who helped this Midwesterner make my contribution. But now it’s time to hang up the space boots (or just let ‘em float there) and embark on a different kind of exploration. I’m incredibly honored to have

With the support of so many incredible people over many years, we all accomplished the mission: we left the International Space Station and human spaceflight a little better than we found it. Thank you. With that, please consider this my out-of-the-office for a while.

Having the opportunity to talk to students across the planet via ham radio while aboard the @Space_Station has been a huge highlight of my time in space. Their enthusiasm, riding those long electromagnetic waves, was completely contagious.

I agree, Paul Rudd -- the world of quantum physics is absolutely fascinating. During the night, I loved floating by the Cold Atom Lab, seeing it all lit up, humming along. I would always smile and think, “Just the Universe, doing her thing. Through quantum mechanics. Per usual.”.

As our stay aboard this amazing, orbiting laboratory comes to an end, here's a look back at a bunch of the science we've conducted during this mission.

Absolutely unreal.

Made a great pass over (sunny!) northern Michigan yesterday as my family was actually down there skiing. I sent these shots to my kids and told them, “Good luck with the Space edition of ‘Where’s Waldo?’”

We had Monday off up here for the holiday, so I did a little sightseeing. This view could never get old.

Open-shoulder surgery on a spacesuit with @AstroDuke — thanks @Astro_DavidS and the entire Mission Control team @NASA_Johnson for the assist. Patient is doing well after a complete checkup, with a trip out the door likely in the next few days. Telemedicine works!

“Join the Navy and see the world,” they said. I guess we’ll give ‘em that one.

RT @Space_Station: .@NASA_Astronauts Josh Cassada and Frank Rubio ended their spacewalk at 2:21pm ET today after successfully installing a….

RT @Space_Station: The Exp 68 crew studied life science and prepared for a Saturday spacewalk after the station boosted its orbit today. ht….

Us, coming home after a long day at work last week. Later I took my family on a video tour inside the ISS. When she saw my spacesuit, my wife hollered, “Thanks, suit!” Yep, and also thanks to the many, amazing people who train us and safely execute the plan from Mission Control.

RT @NASA_Astronauts: Earth's thin atmosphere was penetrated by the last rays of an orbital sunset as the @Space_Station flew 258 miles abov….

.@AstroDuke flew a great approach to capture NG-18, the SS Sally Ride, bringing Exp 68 required EVA hardware just in time for the 11/15 spacewalk, all kinds of exciting science, essential provisions, and even some fresh fruit and cheese which we haven't enjoyed in over a month!.

I've voted my entire adult life, but this year’s voting booth definitely takes the cake. So thankful to everyone – especially Democracy – for allowing me to remain part of this essential process this year.

Ready for Game 3? Expedition 68 says, “PLAY BALL!”.

RT @NASA_Astronauts: After a long day of work yesterday, #Exp68 astronauts still had time for Halloween costumes and trick-or-treating in m….

We’re doing some exciting science up here with partners from all around the planet, but a pause over last weekend allowed @AstroDuke and me to use @esa’s GRIP experiment chair for a slightly different purpose--we even managed not to make a mess.