Preparations continued on May 22 for the first crewed United States space flight since 2011.
The rocket is set to launch on May 27, carrying two USA astronauts to the International Space Station.
This is also notable as the first space flight programme to be carried out as a public-private partnership, with SpaceX producing the Crew Dragon spacecraft and Boeing producing the Starliner. Assuming all goes well with the test flight, it will be used for regular missions to the International Space Station.
The president will travel to Florida for Wednesday's launch, a White House official confirmed on Friday.
Lifting off from Launch Pad 39A atop a specially instrumented Falcon 9 rocket, Crew Dragon will accelerate its two passengers to approximately 17,000 miles per hour and put it on an intercept course with the International Space Station.
This would be the first time NASA has sent astronauts into space in a spacecraft built by a private company. And NASA's effort to restore human spaceflight from USA soil, under the agency's Commercial Crew Program, has suffered years of delays and setbacks. With American shuttles no longer in use, the United States has had to rely on Russian Federation for rides to the station.
The new mission, deemed Demo-2, is "the final major step" to certify Crew Dragon for lengthy missions to the station. Douglas Hurley was a Marine Corps fighter pilot and test pilot who was part of the last Space Shuttle mission in 2011.
NASA isn't sure how long it wants the astronaut duo to spend on the International Space Station after arriving via the Crew Dragon.
Before the launch can happen, however, there is still a lot more work to do for the two space companies to complete, including another check on Monday, May 25.
The two veteran astronauts suiting up for their first flight in a SpaceX Crew Dragon say they're both expecting a much different experience from their Space Shuttle missions. (Gregg Newton/AFP via Getty Images) A Falcon 9 SpaceX heavy rocket lifts off from pad 39A at the Kennedy Space Center in Cape Canaveral, Fla on February 6, 2018.
Rep. Eddie Bernice Johnson (D-Tex.), chair of the House Science Committee, said in a statement she trusts Bridenstine "will ensure that the right decision is made as to whether or not to delay the launch attempt".
The original target for crewed flights replacing the shuttle was 2015, a hiatus that the late Neil Armstrong, the first man to walk on the Moon, once described as "embarrassing". As the rockets begin their descent, they will land on a drone ship called "Of course, I still love you" stationed in the Atlantic Ocean with a boost-back burn followed by an entry burn.
Flying astronauts is a far more hard task, and Boeing and SpaceX have had to overcome challenges that delayed the first launches from 2017.