Follow @NASAHistory on #NationalAstronautDay —and every day—for the latest updates from the history of spaceflight:

It's National Astronaut Day, and tomorrow, Butch Wilmore and Sunita Williams lift off to the stars.

Their mission: to test #Starliner for commercial flight.

Sate travels, star sailors. You are the pride of our great nation.

Love this @nasa photo of #Starliner rolling to the pad. Looking forward to watching this mission!

Crew Flight Test NASA astronauts Butch Wilmore and Suni Williams joined roll to pad activities.

Wilmore is the commander of the spacecraft and Williams is the first female astronaut to pilot and fly on the first flight of a crewed spacecraft.

Another mission milestone complete!

This morning, ULA rolled out the Atlas V rocket for NASA Commercial Crew's upcoming Crew Flight Test mission, carrying Boeing Space's #Starliner spacecraft.

Launch is targeted for 10:34pm ET May 6: go.nasa.gov/3ULmpDN

🚀 The Starliner has arrived at the launch pad atop the mighty Atlas/Centaur stack, and wow, does she look ready to dance among the stars! 🌟 Here with her brave crew and yours truly, the backup, just in case. Dream team assemble! Boeing Space ULA NASA Commercial Crew…

And the mighty #AtlasV is rolling! Launch is Monday around 10:34 EDT. It will be a can’t miss moment!
Thank you Boeing Space and ULA !
NASA Astronauts

.Boeing Space's #Starliner spacecraft atop the #AtlasV rocket is rolling out to its launch pad today. NASA Astronauts Butch Wilmore and Suni Williams will launch to the station aboard the new spaceship at 10:34pm ET on Monday. #LaunchAmerica

Watch history in the making! Keep track of #Starliner 's mission from liftoff to docking on the International Space Station with live coverage on NASA+. go.nasa.gov/4diDMDn

NASA Astronauts Suni and Butch pose with our most excellent Boeing Space Pad team and ULA friends- and if you look carefully you can see the Atlas/Centaur and #Starliner The “stack” is about to move as slow as it ever will until launch on Monday! #Maythe4thBeWithYou

This week on #SpaceToGround , science returned to Earth, a Dragon spacecraft was relocated to a different port, scientific results from the VECTION investigation were released, and get a behind-the-scenes look at NASA’s Boeing Crew Flight Test, scheduled to launch Monday, May 6.

I’m so happy to share President Biden will present Ellen Ochoa, former center director & astronaut NASA's Johnson Space Center, with the Presidential Medal of Freedom.

The Presidential Medal of Freedom is the nation’s highest civilian honor award, & Ellen, along with Dr. Jane Rigby, senior project…

While we get ready for the Crew Flight Test, we're also working on #Starliner spacecraft for future missions. In our factory now: the Starliner-1 crew module that flew OFT-2, a new service module, and the Pad Abort Test vehicle. #NASASocial

🔴 Our Crew Flight Test NASA Social panel is LIVE!

Learn more about #Starliner 's upcoming crewed test flight to International Space Station and use #AskNASA for the opportunity to have your question answered!

twitter.com/i/broadcasts/1…

Even astronauts aren't immune to quarantine! 🚀 Butch and Suni are probably wondering if they stumbled onto a Martian zoo exhibit—viewing Earth from behind the glass. Go #Starliner ! NASA Commercial Crew NASA_Astronauts Boeing Space

One hour until #AskNASA questions are answered!

Join us for NASA's Kennedy Space Center's broadcast at 1:30 pm ET on May 3, when NASA experts will chat about how NASA Commercial Crew launches benefit International Space Station science.

With the Launch Readiness Review complete, tune in to learn more during our NASA Social panel at NASA's Kennedy Space Center!

Have a question for our experts? Use #AskNASA or comment below!

Watch the panel live, starting at 3:30pm ET: go.nasa.gov/4a9vKtw

More: go.nasa.gov/3ybOcnY

LIVE: Experts discuss details ahead of the launch of Boeing Space's #Starliner Crew Flight Test. Liftoff is targeted for May 6 at 10:34pm ET (0234 UTC May 7). Two NASA Astronauts will be aboard testing the end-to-end capabilities of the spacecraft. twitter.com/i/broadcasts/1…