The astronauts will depart from Launch Complex 39A in Florida on SpaceX’s Crew Dragon craft and takeoff on a Falcon 9 rocket at 4:33 p.m. EDT for the Demo-2 mission.

Here are ten things to know before tuning in to watch the launch later today.

Commercial Crew Program

The mission is part of NASA’s Commercial Crew program. Through the program, NASA works with companies in the aerospace industry to develop technology to bring crews into low-Earth orbit and the International Space Station, according to NASA’s website.

Robert Behnken

The two astronauts participating in the mission are Robert Behnken and Douglas Hurley. According to his bio, joint operations commander Behnken had two missions in March 2008 and February 2010 with over 700 hours in space between both missions. A native of St. Ann, Missouri, Behnken became an astronaut in 2000, after graduating with a Bachelor of Science from degree in Mechanical Engineering from Washington University in 1992 and later a doctorate in Mechanical Engineering from the California Institute of Technology in 1997.

Douglas Hurley

According to his bio, spacecraft commander Hurley was a pilot and lead robotics officer for missions in July 2009 and July 2011, the last manned mission. He received a Bachelor’s in Civil Engineering from Tulane University in 1988. Prior to his work with NASA, he was a pilot for the U.S. Marine Corps. He became an astronaut in 2000.

The Crew Dragon

The spacecraft being used for the mission is SpaceX’s Crew Dragon. According to SpaceX’s website, the Dragon has been launched 22 times with 21 visits to the International Space Station and can hold up to seven passengers. It’s also the only craft that’s “capable of returning significant amounts of cargo to Earth.”

What This Could Mean for the Future of Space Travel

The Demo-2 Mission is the last test for SpaceX’s space travel technology to become certified by NASA for missions to the International Space Station, according to the SpaceX site. The SpaceX website calls the Commercial Crew Program a “turning point for America’s future in space exploration” and wrote that it has the building blocks for future explorations of the moon, Mars, and more.

The Length of the Mission is Undetermined

While it will only take the crew about a day to reach the International Space Station and dock, the length of the mission will be determined once on the ISS, “based on the readiness of the next commercial crew launch,” according to the NASA site. For this mission, the Crew Dragon can stay in orbit for 110 days, but the operational version of the craft will be required by NASA to be able to stay in Orbit for 210 Days.

The End of the Mission

The mission will conclude with the craft undocking with both astronauts, according to SpaceX’s website. The Dragon will splashdown off of Florida’s coast and be taken by the SpaceX Go Navigator.

Demo-1 Mission

On March 2, 2019, SpaceX launched a Dragon which docked with the International Space Station autonomously, making it the first craft to do so. On March 2, 2020, the company released a video to celebrate the first mission.

Elon Musk’s Thoughts on the Success of the Mission

Prior to the launch, SpaceX CEO and founder Elon Musk told Bloomberg that the event could be historic if it’s a success. “Assuming it’s successful—I don’t want to seem presumptuous—then it will be an incredible moment for humanity,” he told Bloomberg. “I think it’s something that everyone should be able to celebrate.”

The Last Time Astronauts Were Sent to the Space Station

According to Space.com, the last NASA manned mission was on July 8, 2011. The last mission was a parts delivery so that the space station could keep operating in orbit. “We’ve known this is coming for a long time, but nevertheless, the end of the program - something a lot of these folks have been with for 30 years - the mood is getting more and more somber. The end is just weeks away instead of years away. It’s getting more somber,” Shuttle launch director Mike Leinbach said at the time, according to Space.com.