Astronauts confident Boeing space capsule can safely return them to Earth

Astronauts Sonny Williams and Butch Wilmore's mission aboard the Boeing Starliner has been extended due to technical issues, including helium leaks and thruster failures. NASA is working to diagnose these problems, delaying the astronauts' return until at least the end of July. Meanwhile, the astronauts are contributing to the ISS crew's scientific and maintenance tasks. NASA assures that the astronauts are not stranded and can return in an emergency. The situation highlights the challenges of human spaceflight and spacecraft design.

What does NASA say about the astronauts' ability to return home?

What is the earliest possible time for the astronauts' return according to the text?