CAPE CANAVERAL SPACE FORCE STATION — After the scrub of a Russian launch Thursday morning that would have carried a NASA astronaut and two others to the International Space Station, some may ask why the U.S. is sending astronauts to space on Russian rockets?

Well, it has always been that way since the very first ISS mission, explained Stephen Siceloff, a NASA public affairs officer at Kennedy Space Center.

He says that there has always been a partnership between NASA and the Russian space agency Roscosmos since the Expedition 1 launch on Oct 31, 2000, from the Baikonur Cosmodrome in Kazakhstan.

An expedition means the current crew in the International Space Station.

Back in the day, both nations’ space agencies would take turns to send their own and international crews to the ISS for free, either with the Roscosmos’ Soyuz spacecraft or NASA’s space shuttle.

But once NASA retired its shuttle program in 2011, the Soyuz spacecraft was used heavily.

And it came at a hefty price tag, according to a NASA audit of its commercial crew program.   

“Between 2012 and 2017, NASA will pay Roscosmos $1.7 billion to ferry 30 NASA astronauts and international partners to and from the ISS at prices ranging from $47 million to more than $70 million each. After 2017, NASA hopes to obtain transportation to the ISS from American companies,” the 60-page NASA audit stated.

However, NASA would not get that opportunity to use American companies until 2020 during the first-crewed SpaceX launch of the Demo-2 mission.

Since SpaceX came along, the two nations took turns to ferry crews and cargo to the ISS for free again, Siceloff said.

The ISS is set to retire (and deorbit) in 2030, and NASA, along with other nations’ space agencies have agreed to stick with it until the end. Except for Russia, which stated it would stay until 2028. But Siceloff said he feels Russia will stay until the end.

“Russia will get there,” he told Spectrum News. “It’s been a great partnership.”

Speaking of other nations, there is “an international partnership of five space agencies from 15 countries operating the International Space Station,” NASA stated.

Read the treaty for the space station here.

A brief history of the two nations’ space partnership

The U.S. and Russia have always had some form of space cooperation going back to the 1960s with exchanging information when it came to space biology and medicine, among other things.

The U.S. and the then-Soviet Union signed an agreement in 1972 to explore and use space for peaceful purposes, which is known as the Civil Space Agreement.

Three years later, the two nations did the first-ever international docking between countries, called the Apollo-Soyuz Test Project. It was also the first historic handshake in space between an astronaut and cosmonaut.

In the years since, the two powerful nations have helped or partnered with one another when it comes to robotic probes to the moon, Mars and other planets, or the International Space Station.