The time is running for astronauts stranded in space as National Aeronautics and Space Administration (Nasa) has once again delayed the return of Boeing Starliner due to technical issues.

The Boeing Starliner carrying two people was initially set to return from the International Space Station on June 14, but was pushed back for June 26.

However, now the return is being further pushed back, Live Science reported.

Nasa announcing the decision said, "Mission managers are evaluating future return opportunities following the station's two planned spacewalks on June 24 and July 2."

This is Boeing's first crewed mission which includes United States astronauts Butch Wilmore and Suni Williams.

After years of delays, Boeing's Starliner capsule lifted off from Florida's Cape Canaveral Space Force Station on June 5. But during the 25-hour flight, engineers discovered five separate helium leaks to the spacecraft's thruster system.

Mark Nappi, Boeing's Starliner programme manager, announcing the news at a press conference, said, "We've learned that our helium system is not performing as designed. Albeit manageable, it's still not working like we designed it. So we've got to go figure that out."

The return module of the Starliner spacecraft is currently docked to the ISS's Harmony module. 

However, the Harmony module's limited fuel means Starliner can only stay docked for 45 days, so the window for a safe return flight is narrowing.