65K views · 6.2K reactions | NASA astronauts Jessica Meir and Christina Koch completed today's spacewalk at 2:04 p.m. EST after working seven hours and 29 minutes in the vacuum of space swapping space station batteries. https://go.nasa.gov/2QX5Kwj | International Space Station | Facebook

Historic footage from Apollo 9 shows the first full test of true spacewalk systems in Earth orbit. What may look unstable is normal in microgravity, as visor and checklist hardware float freely. This mission proved astronauts could work safely outside a spacecraft before going to the Moon. Follow @spaceeves #Apollo9 #Spacewalk #NASA #SpaceHistory | SpaceEve