LOS ANGELES -- When it comes to getting to space, the U.S. relies on Russia.
It was a Russian Soyuz spacecraft that transported three crew members, including an American and a Russian, to the International Space Station Thursday. American astronauts and satellites cannot currently get off the ground without engines made in Russia.
About half of all U.S. military rockets launch with the help of Russian engines, including the Air Force rocket that carried a U.S. spy satellite last week.
"It's the only engine in the world in power class, nearly a million pounds of thrust, and it's extremely reliable," said Bill Harwood, a space writer and CBS News consultant.
But the 15-year arrangement between the U.S. and the Russians is now threatened by the fallout from the crisis in Ukraine. The U.S. imposed sanctions on some Russian officials, including Dmitry Rogozin, the man who helps run the space and defense program. He's now threatening to ban Russian rocket engines on U.S. military flights. On Twitter, he suggested the U.S. deliver its astronauts to the international space station using a trampoline rather than Russian spacecrafts.
"It's all served to stir up the pot and created widespread awareness of just how much dependence on Russian space technology there actually is," said Harwood.
There are 16 Russian engines currently in the U.S. If the country doesn't get more, nine missions will be delayed, costing the government $2.5 billion, according to the RD-180 Availability Risk Mitigation Study.
California-based SpaceX will unveil a new spacecraft Thursday night that it hopes will carry humans. The U.S. government is in the process of certifying SpaceX for military missions, but even if it does, there would still be launch delays without Russian engines.
Sen. John McCain (R-Ariz.), wants the U.S. government to stop using Russian-made engines altogether. But it could take an estimated 5 years and $1.5 billion to fully develop an American alternative.