NASA and Boeing are targeting a June 26 return to Earth of the Boeing Starliner from the International Space Station, officials said Tuesday.

Starliner's first crewed mission to the ISS, which had been scheduled to last about eight days, has been extended due to thruster malfunctions and helium leaks.

The spaceship blasted off from Florida atop a United Launch Alliance Altas V rocket on June 5 following years of delays and safety scares—as well as two aborted launch attempts that came as astronauts were strapped in and ready to go.

NASA and Boeing officials said at a press conference that they were looking at a return date of no earlier than June 26 for the two astronauts, Butch Wilmore and Suni Williams, both ex-US Navy test pilots.

NASA aims to construct a lunar base through the Artemis program, a manned lunar exploration initiative. However, the practical reality of what the general public envisions for the space base differs somewhat from well-known science fiction movies. To build a base on the moon using abundant and diverse construction materials, significant transportation costs are involved. All these materials must be launched from Earth using rockets.

Because transporting construction materials from Earth to the moon is costly and time-consuming, local materials must be utilized in order to establish a lunar base.

One promising method for lunar base construction using local materials is microwave sintering, which solidifies lunar regolith (soil) below its melting point.