Rocket builder vs NASA astronaut: Musk, Sen. Kelly have social media skirmish over Ukraine

WASHINGTON − Elon Musk and Sen. Mark Kelly, D-Ariz., traded jabs on social media Monday, after the billionaire space entrepreneur called the former NASA astronaut a "traitor" for his recent trip to Ukraine.

Kelly, Arizona's senior senator and former Navy combat pilot, was in Ukraine for about 36 hours, departing the U.S. Wednesday and returning 10 p.m. Sunday.

"What I saw proved to me we can’t give up on the Ukrainian people," Kelly said of his trip, in a post Sunday evening. "Everyone wants this war to end, but any agreement has to protect Ukraine’s security and can’t be a giveaway to Putin."

The Democratic senator chronicled online his various experiences and meetings while visiting the war-torn country. This was Kelly's third time in Ukraine in the past two years, he said.

Elon Musk responded in a comment on the post Sunday saying, "You are a traitor."

The attack from Musk, one of President Donald Trump's closest allies, comes amid growing tension between the Trump administration and Ukraine officials. After a particularly dramatic White House meeting between Trump, Vice President JD Vance and Ukrainian President Volodymyr Zelenskyy last month, the U.S. paused military aid, including weapons and intelligence, to Ukraine.

Kelly said the administration has approached the situation "rather poorly."

"The decisions that have been made over the last couple weeks with regards to Ukraine are making all of us less safe," he told reporters Monday.

And there was no love lost between the senator and Musk.

"Traitor?" Kelly replied online. "Elon, if you don’t understand that defending freedom is a basic tenet of what makes America great and keeps us safe, maybe you should leave it to those of us who do."

To reporters on Monday, Kelly said, "He's not a serious guy."

"He should go back to building rockets."