July 19 (UPI) -- President Donald Trump praised the 1969 moon-landing mission as "one of the great achievements" in U.S. history in an Oval Office meeting with Apollo 11 astronauts, who offered their thoughts on whether the U.S. should return to the moon before heading to Mars.
Trump spoke with Buzz Aldrin and Michael Collins, the two surviving members of the mission, and the family of the late Neil Armstrong, the first person to walk on the moon. The meeting marked the 50th anniversary of the day Armstrong stepped foot on the moon July 20, 1969.
"Tomorrow will represent 50 years from the time we planted a beautiful American flag on the moon," Trump said.
The president spoke about NASA's seven-year plan to land humans on the moon for the first time since 1972 before making a landing on Mars.
"We don't know what we're going to find on Mars, but it certainly is going to be a trip that's very interesting," Trump said. "To get to Mars, you have to land on the moon, they say."
Collins, who served as command module pilot for Apollo 11, said he preferred a "Mars direct" approach. In an interview with UPI earlier this week, Collins said NASA's plan to build a lunar base, with a platform orbiting the moon, is heading in the wrong direction.
"I see more moon missions as delaying Mars, which is a much more interesting place to go," Collins said.
But during the Oval Office meeting, Aldrin described those in support of a "Mars direct" approach as "impatient."
NASA Administrator Jim Bridenstine, who was also on hand for the Oval Office meeting, said Monday that he and Trump are on the same page regarding the agency's primary objectives.
"The president said to go to the moon sustainably, in other words, to stay," Bridenstine said. "And the president said to go with commercial partners, to go with international partners, and to utilize the resources on the moon for future space exploration."