Two NASA astronauts who traveled initially of June to the Worldwide House Station had been initially scheduled to return dwelling a few weeks in the past, finishing a test flight of Boeing’s Starliner spacecraft.

As an alternative, the astronauts, Butch Wilmore and Suni Williams, will stay on the station for a number of weeks longer as NASA and Boeing engineers proceed to check misbehaving thrusters on the car.

However don’t name the astronauts caught or stranded, officers stated on Friday. And there’s no speak of a rescue mission.

“We’re not caught on I.S.S.,” Mark Nappi, this system supervisor at Boeing for Starliner, stated throughout a information convention on Friday. “The crew is just not in any hazard.”

Steve Stich, the supervisor of NASA’s business crew program, additionally tried to allay worries.

“The car at station is in fine condition,” he stated. “I need to make it very clear that Butch and Suni are usually not stranded in house. Our plan is to proceed to return them on Starliner and return them dwelling on the proper time.”

Mr. Stich then added that the correct time could be after extra evaluation on why five of Starliner’s 28 maneuvering jets behaved oddly because the spacecraft approached the house station. Starliner’s computer systems, which had been autonomously guiding the spacecraft, had been in a position to compensate with the remaining thrusters.

4 of the 5 thrusters now look like working correctly; the opposite thruster is not going to be used in the course of the journey dwelling. Mission managers anticipate that Starliner can undock from the house station and take Mr. Wilmore and Ms. Williams on their return journey from house, however they don’t totally perceive what prompted the issue.

Deadly disasters in NASA’s historical past, just like the lack of the Challenger and Columbia house shuttles, have taught mission managers to be cautious and curious when one thing is just not fairly proper.

“I believe they’re doing their due diligence,” Wayne Hale, a retired NASA flight director, stated in an interview. “Being in no hurry to come back dwelling, it makes a substantial amount of sense to take the time to assemble as a lot data as attainable in order that they will ensure that the issues are all mounted. That makes a substantial amount of sense, to take your time.”

Mr. Nappi supplied the same appraisal throughout Friday’s information convention, saying it was prudent to make use of the time for extra evaluation.

“It might be irresponsible for us, if we’ve got time and we need to do extra, to not do it,” he stated.

Starting subsequent week, engineers will conduct floor checks at NASA’s White Sands Check Facility in California utilizing a thruster similar to those on Starliner. The firings will reproduce those that Starliner carried out in house.

That may in all probability take a few weeks, Mr. Stich stated. “Then we’ll give engineers an opportunity to go take a look at that thruster,” he stated. “This would be the actual alternative to look at a thruster, identical to we’ve had in house.”

Engineers will be unable to instantly look at the troublesome thrusters on the spacecraft now in orbit as a result of they’re situated on what is called the service module. That half will probably be jettisoned in the course of the flight dwelling, burning up within the environment.

“The check will assist us perceive thruster efficiency and will give us one hundred pc confidence that the whole lot we’ve seen on orbit is okay,” Mr. Stich stated. “It’s only one extra piece of knowledge that we are able to have earlier than we really deorbit the car.”

Former NASA officers like Mr. Hale famous that mission managers’ brushing apart engineers’ issues contributed to earlier deadly accidents.

Through the launch of the house shuttle Columbia in January 2003, a chunk of insulating foam from the exterior gasoline tank broke unfastened and struck the shuttle’s left wing. Mr. Hale, who was about to start a brand new place because the launch integration supervisor for the shuttle program, known as contacts on the Protection Division, asking whether or not it had the power to visually examine the shuttle for harm.

However managers larger up within the NASA chain of command weren’t curious and informed Mr. Hale to retract the request for assist. He complied.

What nobody knew on the time was that the froth strike had punched a gap within the wing. Because it returned to Earth, Columbia disintegrated, killing the seven astronauts aboard.

“Wanting again on it, definitely within the Columbia case, there weren’t sufficient questions requested,” Mr. Hale stated. “There was not sufficient time taken. And the lesson clearly has been discovered that you just take the time that’s out there to get to essentially the most full reply and reply all of the questions that any of the consultants might need.”

Whereas NASA and Boeing examine the spacecraft, Mr. Stich of NASA stated, Mr. Wilmore and Ms. Williams would be capable to hop into Starliner to move dwelling within the case of an emergency on the house station. Certainly, when a dead Russian satellite unexpectedly broke apart in orbit on Thursday, they briefly took refuge within the car, and would have used it if the house station had been struck by a big piece of particles.

The capsule is at the moment licensed to spend 45 days docked on the house station, due to limitations to the present design of Starliner’s batteries. However to date, the batteries have carried out nicely, and the keep may be prolonged past 45 days, Mr. Stich stated.

Starliner is just not NASA’s solely drawback to resolve for the time being. A spacewalk was reduce quick on Monday when water leaked out of an umbilical cord that connects to a spacesuit whereas astronauts had been within the airlock. Engineers nonetheless don’t perceive what occurred.

“We’ve got to go give it some thought some extra,” stated Invoice Spetch, NASA’s operations integration supervisor for the Worldwide House Station program.

The following spacewalk, which had been scheduled for Tuesday, is not going to happen till no less than late July, Mr. Spetch stated.