Space travel company Virgin Galactic on Wednesday said it had reached an agreement with Boeing subsidiary Aurora Flight Sciences to build two new air launch carrier aircraft for its spaceships.

These new motherships will replace Virgin Galactic‘s existing carrier plane — the VMS Eve built by Scaled Composites — with the first of the new aircraft due to enter service by 2025. The company also plans to launch new Delta-class spaceships the same year.

The value of the contract was not disclosed.

Virgin Galactic CEO Michael Colglazier said in a statement the next generation motherships “will be faster to produce, easier to maintain and will allow us to fly substantially more missions each year.”

He added the goal was 400 flights per year from the company’s base in New Mexico, called Spaceport America.

Todd Citron, Boeing‘s Chief Technology Officer added, “Boeing is excited to contribute our culture of safety, our operational excellence, and our expertise in aircraft design and manufacturing to help advance human space travel.”

The statement did not however offer any technical details.

Established in 2004, Virgin Galactic is looking to build on the success of a high profile test mission in 2021, which saw its founder Richard Branson experience a few minutes’ weightlessness on the edge of space.

Unlike other companies that use vertical-launch rockets, Virgin Galactic uses a carrier aircraft that takes off from a runway, gains high altitude, and drops a rocket-powered spaceplane that soars into space before gliding back to Earth.

Both VMS Eve and the company’s spaceplane VMS Unity are at the company’s production facility in Mojave, California, where they are undergoing maintenance. Virgin Galactic said its first commercial missions will begin in the first quarter of 2023.