History in the making: 2 NASA astronauts enter ISS after 19-hour journey

Two NASA astronauts on Sunday entered the International Space Station from SpaceX's Dragon spacecraft after a historic launch from the Kennedy Space Center in Florida, marking the dawn of a new age in commercial space travel.

The National Aeronautics and Space Administration (NASA), which is an independent agency for space research, aeronautics and related programmes in the US, confirmed the arrival of astronauts Bob Behnken (49) and Doug Hurley (53) at the ISS.

Read: Russian space agency calls Trump's reaction to SpaceX launch "hysteria"

"This is the first time in human history @NASA_Astronauts have entered the @Space_Station from a commercially-made spacecraft. @AstroBehnken and @Astro_Doug have finally arrived to the orbiting laboratory in @SpaceX's Dragon Endeavour spacecraft," NASA said in a tweet.

They were welcomed aboard the ISS where they became members of the Expedition 63 crew, which currently includes NASA astronaut Chris Cassidy.

The docking had taken place 19 hours after a SpaceX Falcon 9 rocket blasted off from the Kennedy Space Center.

Elon Musk's SpaceX company earlier confirmed the successful docking of the NASA astronauts with the ISS, the orbiting laboratory.

"Docking confirmed - Crew Dragon has arrived at the @space_station!" the California-headquartered company announced on Twitter.

Watch: The historic moment of SpaceX Falcon 9 rocket launch

Saturday's liftoff also assumes significance as it marks the launch of humans into orbit from US soil for the first time in nearly a decade.

The SpaceX Crew Dragon spacecraft, carrying NASA astronauts Behnken and Hurley, lifted off at 3:22 pm EDT Saturday atop the company's Falcon 9 rocket from Launch Complex 39A at NASA's Kennedy Space Center.

Read: NASA astronauts head for International Space Station on historic SpaceX flight

With the liftoff, SpaceX became the first private company to launch people into the orbit, a feat achieved previously by only three governments: the US, Russia and China.

The successful launch, which was postponed early this week due to inclement weather, gave Americans something to cheer about as in the last three months they have lost over 100,000 of their countrymen due to the coronavirus that has brought the economy to its knees. More than 40 million people have lost their jobs.

Top US leadership including President Donald Trump, First Lady Melania Trump, and thousands of curious Americans had gathered to watch the launch live on a bright Sunday afternoon. Congratulating Musk, NASA and the astronauts, Trump described the launch day as a great day for the country.

The President said he spoke with Musk, whom he called one of the "great brains."

He also spoke with the two NASA astronauts prior to the takeoff. Secretary of State Mike Pompeo said that "Launch America is the first big step on our roadmap to the Moon for Artemis".

NASA's Artemis programme, the US initiative to explore more of the lunar surface, aims to land the first woman and next man on the Moon by 2024.

"This is a dream come true for me and everyone at SpaceX,” said Musk, who is also the CEO of Tesla.

"It is the culmination of an incredible amount of work by the SpaceX team, by NASA and by a number of other partners in the process of making this happen," he said.

"Today a new era in human spaceflight begins as we once again launched American astronauts on American rockets from American soil on their way to the ISS, our national lab orbiting Earth," said NASA Administrator Jim Bridenstine.

The launch of this commercial space system designed for humans is a phenomenal demonstration of American excellence and is an important step on our path to expand human exploration to the Moon and Mars, he said.

"Today, in lifting our ambitions and our imaginations to the heavens, the United States has once more reshaped the future of space travel," said Joe Biden, former US Vice President and Democratic Party's presumptive presidential nominee.

Their voyage not only marks the return of American astronauts travelling to space from US soil, but a pioneering new phase of public-private cooperation for the peaceful exploration of space, Biden said as he asserted that the seed of today's launch was planted by the Obama-Biden administration.

"We planted the seeds of today's success during the 2009 Recovery Act, which according to NASA, has saved taxpayers up to USD 30 billion and invigorated an aerospace industry in Florida that accounts for more than 130,000 jobs in the state," he said.

Known as NASA's SpaceX Demo-2, the mission is an end-to-end test flight to validate the SpaceX crew transportation system, including launch, in-orbit, docking and landing operations.

This is SpaceX's second spaceflight test of its Crew Dragon and its first test with astronauts aboard, which will pave the way for its certification for regular crew flights to the station as part of NASA's Commercial Crew Programme.