Weather conditions did not allow for a SpaceX Crew Dragon spacecraft rocket launch late Wednesday afternoon from Kennedy Space Center in Florida.
The launch was scrubbed just under 17 minutes before the expected launch of two veteran NASA astronauts.
Mission controllers determined the weather conditions, specifically electrical activity in the launch area, were not safe for launch.
The space mission, which will be the first time the United States has launched its own astronauts into space for the first time in almost a decade, is now scheduled for Saturday at 3:22 p.m. ET.
Due to the COVID-19 pandemic, NASA is discouraging people from coming to view the launch at Kennedy Space Center. Instead, NASA will stream the launch broadcast Saturday on its own website.
The countdown had proceeded smoothly throughout the afternoon and both astronauts were aboard and prepared for the flight to the International Space Station.
Once launched, the two astronauts -- Robert Behnken, 49, and Douglas Hurley, 53 -- will remain aboard the space station for an undetermined amount of time, perhaps as long as three months.
The rocket and systems were built by SpaceX, a private California-based company founded by entrepreneur Elon Musk. It's being funded by the U.S. government under NASA’s Commercial Crew Program.
Musk visited with both astronauts before they boarded the spacecraft. The two astronauts were transported to the launch pad aboard Tesla vehicles, a company also founded by Musk.
In 2010, NASA changed from space flight being a government-funded venture to contracting with private companies for low-Earth orbit efforts, allowing the agency to focus on longer-range missions, perhaps back to the moon in a few years.
Since the space shuttle program ended in 2011, NASA has relied upon Soyuz rockets to carry U.S. astronauts from launch pads in Russia.
Launch Complex 39 is a rocket launch site at the John F. Kennedy Space Center on Merritt Island in Florida, United States. The site and its collection of facilities were originally built as the Apollo program's "Moonport" and later modified for the Space Shuttle program.
SpaceX has leased the complex during the development of its rocket program. This will mark the first time SpaceX has launched a rocket with astronauts on board.