Astronaut Mike Hopkins sworn into the Space Force from orbit

NASA astronaut Mike Hopkins was sworn in as the newest member of the U.S. Space Force Friday from his post onboard the International Space Station.

Why it matters: Hopkins is the first NASA astronaut to serve in the Space Force.

• "Today, you will be the first... Space Force astronaut, that will be living space," General John Raymond, the Space Force's Chief of Space Operations said to Hopkins during the swearing in.

The big picture: NASA and the U.S. military have had a close relationship since the earliest days of the space agency.

• Some of the first astronauts were test pilots from the military, and today, the majority of astronauts that have served NASA were military service members.
• "The very first astronaut was Alan Shepard from the Navy and the first airman in space was Gus Grissom. The first marine in space was John Glenn, and the first army officer... in space astronaut was Robert Stewart," Raymond said.

Between the lines: When the announcement of Hopkins' swearing in was made earlier this year, some space watchers questioned whether it would muddy the waters with the public's understanding of what the Space Force does.

• The point of the Space Force is not necessarily to send people to space but to protect essential hardware — like spy and GPS satellites — from potential bad actors.

• "The skill sets that you need to be an astronaut is totally different than the skill set you need to be a space operator in the Space Force," Todd Harrison, an analyst at the Center for Strategic and International Studies, told Axios in November.
• Hopkins' swearing in aboard the space station also raised eyebrows. The space station is considered a tool of diplomacy and peace, not warfighting, and some experts are concerned the transfer aboard the station may send mixed signals to international partners.

Go deeper: The Space Force heads to space