"How is it that we're spending hundreds of thousands of dollars in U.S. taxpayer money [on Russian engines] at a time when Russia is the process of invading Ukraine?" said Musk. "It would be hard to imagine that [Russian Deputy Prime Minister] Dmitry Rogozin is not benefiting personally from the dollars that are sent there."
Rogozin is among nearly a dozen Kremlin-linked officials who were personally targeted last month by White House sanctions.
The market for launching national security rockets into space is dominated by a joint venture between aerospace giants Boeing and Lockheed Martin. The partnership, known as United Launch Alliance, secured a five-year contract in December 2013 with the U.S. Air Force for rocket boosters and launch services worth up to $9.5 billion.
"We are aware of Mr. Musk's press conference and are reviewing the transcript," said Christa Bell, a ULA spokesperson.
The Air Force did not immediately respond to requests for comment.
Musk has criticized ULA's close relationship with the government in the past. But likely on his mind are the 14 other government launches that will be up for grabs starting next year. The Defense Department has estimated that it could spend $70 billion on space launches through 2030. To bid on those contracts, SpaceX will need a certification from the Air Force. But, he said, that process keeps getting held up.
For the government, it's a question of reliability versus cost. Musk claims to be able to save the government a substantial amount on each launch. The Pentagon, however, has strong ties with Boeing and Lockheed that go back decades.
"It's a good model in that it delivers a very reliable launch vehicle," said James Lewis, a space policy scholar at the Center for Strategic and International Studies. "If you just spent a billion dollars on a satellite, it's really painful when it crashes — particularly when it's self-insured so that Uncle Sam has to eat it."
Musk says it costs $60 million to launch Space X's Falcon 9 rocket. He hopes to drive those costs down by developing a reusable rocket booster known as the Falcon 9R. On Friday, Musk announced that SpaceX had successfully tested a version of the 9R by "soft-landing" it on a patch of ocean. The rocket was destroyed by heavy waves about eight seconds after it landed, but the entrepreneur is already looking ahead to future tests.
Eventually, the goal is to land the rocket upright on its extendable legs "with the accuracy of a helicopter," Musk told reporters.