Stratolaunch, the Seattle-based space venture created by Microsoft co-founder Paul Allen seven years ago, says it’s discontinuing its programs to develop a new type of rocket engine and a new line of rockets.

The company said it would continue work on the world’s largest airplane, which is designed to serve as a flying launch pad for rockets. Last week, Stratolaunch put its 385-foot-wide, twin-fuselage plane through a high-speed taxi test that many saw as a precursor for its first test flight at Mojave Air and Space Port.

RELATED: What's next for Paul Allen's big investments?

RELATED: Paul Allen’s Stratolaunch unveils plans for new family of rockets, space plane | GeekWire

“Stratolaunch is ending the development of their family of launch vehicles and rocket engine. We are streamlining operations, focusing on the aircraft and our ability to support a demonstration launch of the Northrop Grumman Pegasus XL air-launch vehicle,” the company said in an emailed statement. “We are immensely proud of what we have accomplished and look forward to first flight in 2019.”

Read more on GeekWire.com.