While there has been a lot of hype and buzz surrounding Musk and SpaceX, the NASA astronauts have largely shied away from the spotlight.
In a video released by NASA ahead of the launch, the two were bashful when asked about what makes the other great and joked with each other like longtime friends.
There are a lot of similarities between Doug Hurley and Bob Behnken. Both joined NASA's astronaut program in 2000, they are both married to fellow NASA astronauts and they are fathers. They even share the same taste in music.
Here is everything you need to know about Hurley and Behnken, the astronauts NASA administrator Jim Bridenstine has called "truly the best of us."
Hurley, 53, was a U.S. Marine Corps fighter pilot prior to being selected as an astronaut by NASA in 2000.
He piloted two spaceflight missions in July 2009 and July 2011, and has logged a total of 683 hours in space.
Hurley is a native of Apalachin, New York. When he's not flying to space, he enjoys hunting and spending time with his family in the Texas Hill Country, according to his official NASA biography.
Hurley is married to fellow NASA astronaut Karen Nyberg. They have one son.
Ahead of the launch, Hurley shared an image that his son drew of the Crew Dragon spacecraft on Instagram.
Behnken, 49, a veteran Air Force test pilot, was first selected as an astronaut in July 2000.
The St. Ann, Missouri, native has logged more than 708 hours in space and flew on two space shuttle flights in March 2008 and February 2010. He has also logged more than 37 hours of spacewalking on six different occasions, according to NASA.
Behnken is married to fellow NASA astronaut K. Megan McArthur and has a young son.
Bringing spaceflight capabilities back to the U.S. is important to him so that his son can witness him launch, Behnken said in a video released by NASA.
"On a deeply personal level, I’m really excited that my son is going to get a chance to see me launch into space," he said. "Being an astronaut has been a little bit of an abstraction thing for him because he’s seen me do it in old videos but he hasn’t seen me do it for real."
"I'm just one piece of a multi-thousand member team that is going to hopefully pull this off in short order," he added. "It's inspiring to me and I'm just excited to be a part of it."