First son Eric Trump was the third of Trump's children to address the Republican National Committee Convention, following speeches by his half-sister Tiffany Trump and big brother Donald Trump, Jr.
In an argument that NASA may dispute, he said Americans would "soon" be headed to Mars.
"Every day my father fights for the American people. The forgotten men and women of this country, the ones who embody the American spirit, which is unlike anything else in the world. It built the New York City skyline, it built the Hoover Dam and soon -- under my father's leadership -- it will send Americans to Mars," he claimed.
Cristóbal Alex, a senior advisor to Joe Biden, blasted the first son's speech.
"Eric Trump is talking about Mars travel. Americans are worried about COVID and jobs," he said.