The Soyuz MS-12 spacecraft
© Reuters / Shamil Zhumatov
FILE PHOTO: The Soyuz MS-12 spacecraft
Soyuz rockets stand ready to deliver astronauts to space if US manned spacecraft development is delayed, Roscosmos said, after NASA announced plans to purchase additional seats onboard the Russian spacecraft.

"We are ready to help American partners in case trials of their new manned spacecraft are delayed," chief of the Russian Space Agency Roscosmos Dmitry Rogozin said on Twitter. "We agree with NASA's proposal to use both US and Russian spacecraft for delivering mixed international crews to the [International Space Station] ISS in the future."

The news comes in the wake of delays to NASA's Commercial Crew Program which has yet to develop and certify an American alternative to the Soyuz spacecraft that can ferry astronauts to space from US soil. With both SpaceX's Crew Dragon and Boeing's Starliner development nearly two years past the original deadline, NASA is not taking any chances with private American aerospace manufacturers and is seeking to purchase two additional Soyuz seats from Roscosmos.

"This Soyuz seat procurement ensures uninterrupted access to the ISS in the event of a delay in US commercial crew launches, mitigating the significant risk to ISS safety and operations that the absence of US crew members at any point in time would cause," NASA's procurement notice states.

The additional seats would ensure US astronauts' access to the station through September 2020. NASA has been relying on Russian help to get to the space lab since it grounded its shuttle fleet in 2011, paying Roscosmos roughly $81 million per seat.