(BSS/AFP) - NASA on Monday announced it was planning new missions using Boeing`s Starliner spacecraft, the first since the vessel`s botched test flight left two astronauts stranded at the International Space Station for months.

Starliner was last used in June 2024 to transport US astronauts Suni Williams and Butch Wilmore to the ISS for what was originally an eight-to-14-day mission.

However, the spacecraft`s propulsion had problems during orbit, and it was deemed unfit to fly them back -- leaving them stranded at the orbiting outpost for a period that stretched for nine months before they were able to return.

In a report assessing the troubled test flight, NASA blamed engineering vulnerabilities in Starliner, classifying them a "Type A" mishap -- the same as the deadly Challenger and Columbia space shuttle disasters.

Boeing and NASA have worked to fix these issues in time for two upcoming missions involving the spacecraft, which serves a key role for the US space agency`s long-term goals.

The first mission, expected by December at the earliest, will be an uncrewed mission returning to the ISS "to validate the recent remediation effort," NASA administrator Jared Isaacman told reporters Monday.

"From there, we will gather data, continue implementing the remaining changes recommended in the (Program Investigation Team) report, and plan for a crewed Starliner Two mission in 2028," he added.

Having a successful crewed Starliner mission is essential, as rival SpaceX has said it plans to end production of its reusable Crew Dragon capsules, which have served as the only other spacecraft to take US astronauts to the ISS since 2020.