NASA is "taking its time" as it conducts a critical review to decide when to bring astronauts Butch Wilmore and Suni Williams back to Earth from the International Space Station (ISS).

Wilmore and Williams entered space on Boeing's "Starliner" spacecraft in June this year. During the docking process, the spacecraft's thrusters failed to operate as planned. NASA and Boeing have since conducted thruster tests on the ground and in space, but new details suggest otherwise after agency officials revealed last week that a review could take place this week.

The last time NASA spoke to the media about its decision to send two astronauts home was last week. At this event, commercial crew program managers from NASA and Boeing revealed that the deformed PTFE seal inside the "Starliner" thruster was the cause of the thruster failure during docking. They made significant progress last week, though, as they replicated the thruster anomalies on Earth to determine the root cause behind the problem.

NASA Commercial Crew Program Manager Steve Stich also revealed that the team will conduct a key test in space before deciding on a review to return the crew. They conducted this test over the weekend, and NASA later released news that after the test, all thrusters tested were restored to pre-flight levels.

Stich outlined in media talks that his agency will work to "conduct an agency review as soon as it is ready." It could be as early as late next week.

Boeing's Starliner docks with the International Space Station. Image: NASA

It now appears that NASA and Boeing will spend more time analyzing data from Starliner than the best lift openings. In a press release issued earlier today, NASA said that as part of several operations leading up to Starliner's return to Earth from the International Space Station, teams are "taking time to analyze the results of the recent docking heat" test. NASA added that teams on the ground and aboard the International Space Station are conducting simulations to train for the spacecraft's return.

The crucial agency review discussed by Stich now appears to have been postponed to next week. According to NASA, Starliner's return plan will continue "until next week" before the agency decides when it will conduct a review. If the review allows the crew to return to Boeing's spacecraft, NASA and Boeing will determine a return date for Starliner.

Mark Nappi, Boeing's Starliner program leader, added last week that after the review is complete, Boeing will be able to provide all details to NASA to move forward with the review. Stich has emphasized that analyzing the data is "a very complex subject" because the NASA team must understand "how helium leaks, thrusters and GNC flight control systems work during a deorbit burn."

Keeping "everyone informed" will be the next step NASA must take before conducting a review, Stich added.