CAPE CANAVERAL, Fla. — President Trump on Saturday celebrated the successful launch of U.S. astronauts into space, an achievement he heralded as a moment of unity for Americans even as he spent part of the day exacerbating tensions in the country amid continuing protests over the killing of a black man by police in Minneapolis.

Two astronauts blasted off aboard a SpaceX rocket from Kennedy Space Center on Saturday afternoon under blue skies, marking the first such trip from the United States in almost a decade as well as the first time a private corporation launched people into orbit.

“A new age of American ambition has now begun,” Trump said following the launch. He added: “Those of us who saw the spectacular and unforgettable lift off this afternoon watched mor than an act of history. We watched an act of heroism.”

Trump has made the U.S. space program a priority, making the cosmos a place both to be militarized as well as an opportunity for economic expansion. The White House reconstituted the National Space Council with Vice President Pence as its chair, speeding up efforts to return to the moon, standing up the new Space Force military branch, and slashing regulations while promoting the growth of a commercial space industry.

Trump and Pence were on site Saturday as well as earlier in the week for the original launch date before it was canceled due to weather with astronauts aboard the rocket for their journey.

On Saturday, Trump highlighted his commitment to the space program while exaggerating the extent it had been abandoned by his predecessors.

“The United States has regained our place of prestige as a world leader, as has often been stated, you can’t be number one on Earth if you are number two in space,” he said. “And we are not going to be number two anywhere.”

While Trump celebrated the U.S. astronauts’ return to space, he couldn’t escape the turmoil in the country as protests once again were held in cities across the country sparked by outrage over the killing of George Floyd by a Minneapolis policeman on May 25.

Those protests included a demonstration outside the White House on Friday night that saw clashes between protesters and the Secret Service.

Saturday morning Trump took a defiant rather than conciliatory stance toward those protesters.

“I was inside, watched every move, and couldn’t have felt more safe,” the president tweeted. “They let the ‘protesters’ scream & rant as much as they wanted, but whenever someone have been greeted with the most vicious dogs, and most ominous weapons, I have ever seen.”

He later seemed to urge his supporters to show up outside the White House on Saturday night to counter the protesters.

“Tonight, I understand, is MAGA NIGHT AT THE WHITE HOUSE???” he wrote.

But in Florida, Trump struck a theme of unity that was at odds with his tweets, emphasizing the pain over the death of Floyd, the disturbing images of which were captured on video by people on the scene.

“Yesterday I spoke to George’s family and expressed the sorrow of our entire nation for their loss. I stand before you as a friend and ally to every American seeking justice and peace,” he said before moving on to address the successful rocket launch. “Healing, not hatred, justice, not chaos, are the mission at hand.”

Trump also mentioned the “pain” caused by the coronavirus pandemic that spread across the country, killing more than 100,000 Americans and devastating the economy.

“The same spirit of American determination that sends our people into space will conquer this disease,” Trump said.

Trump made his comments in the cavernous vehicle assembly building, made famous during the space shuttle program.

About 300 people — many politicians, but also NASA and SpaceX engineers and their family members — were in the audience.

Most of them wore masks, but there was no social distancing, and some — such as Education Secretary Betsy DeVos — did not wear masks.

The loudest applause, along with two sustained standing ovations, went to SpaceX owner Elon Musk.

“Thank you, Elon,” Trump said when Musk took a couple of bows from his seat with the audience.

Astronauts Bob Behnken and Doug Hurley rode a SpaceX Falcon 9 rocket in a SpaceX Crew Dragon capsule. They are headed to the International Space Station. Saturday’s launch was the first time since July 2011, when the space shuttle program ended, that American astronauts have lifted off from American soil.