New Delhi:

Astronaut Sunita Williams, currently in space, will see 16 sunrises and sunsets on New Year as the International Space Station, where she is located, keeps on the move. A post on X today from the space station handle read: “As 2024 comes to a close today, the Exp 72 crew will see 16 sunrises and sunsets while soaring into the New Year. Seen here are several sunsets pictured over the years from the orbital outpost”. 

As 2024 comes to a close today, the Exp 72 crew will see 16 sunrises and sunsets while soaring into the New Year. Seen here are several sunsets pictured over the years from the orbital outpost. pic.twitter.com/DdlvSCoKo1

— International Space Station (@Space_Station) December 31, 2024

Ms Williams, who started for the space station in June in Boeing’s Starliner spacecraft along with astronaut Barry Wilmore, and initially expected to be back in 9 days, had to spend Christmas at the space station too. 

In a video shared by US space agency NASA, she said it was a “great time to be up here”. Her colleagues were seen sporting Santa caps – apparently part of holiday supplies sent up to the orbiting laboratory by NASA on SpaceX Dragon capsule.

“Welcome to the International Space Station as we get ready for the Christmas holidays. It’s a great time up here, we get to spend it with all of our ‘family’ on the International Space Station. There are seven of us up here and so we’re going to get to enjoy company together,” Ms Williams is heard saying in the video.

Ms Williams and Mr Barrymore are now hoping to be back in March after yet another postponement by NASA. They were set to return in February 2025, but it was postponed due to the delay in SpaceX’s Crew-10 mission, who have to relieve them.

The Crew-9’s two astronauts had arrived at the space station in late September, with two empty seats for Wilmore and Williams. The plan was for all four to return home in February 2025.

SpaceX has launched its Crew Dragon spacecraft on a “rescue mission” to bring back two astronauts stranded at the International Space Station (ISS) since June. Butch Wilmore and Sunita Williams travelled to the space station on Boeing’s Starliner spacecraft, which was on its first mission with a human crew.

But several engines malfunctioned once in space and the vehicle was found to be leaking helium, which is essential for the functioning of its engines. After weeks of analysis and discussion by NASA and Boeing engineers, the space agency decided to send Wilmore and Williams home on the Crew Dragon because of safety concerns with Starliner.

For Boeing, this embarrassing episode is the latest in a long series of problems. They include fatal crashes of its 737 Max aircraft in 2018 and 2019 and a door that blew out mid-flight on a 737 Max 9 plane in January 2024.

Boeing’s Starliner craft has been beset with challenges since 2014 when Nasa awarded both Boeing and Space X with contracts to develop spacecraft that could transport astronauts and supplies to and from the ISS as part of its Commercial Crew Program (CCP).

Boeing received US$4.2 billion (£3bn) to develop the Starliner craft, while SpaceX received US$2.6 billion (£1.9 billion) to develop the Crew Dragon. Despite the lower contract value, SpaceX’s Crew Dragon has performed much better than Starliner, making a successful first crewed flight in 2020 and launching regularly to the ISS ever since. Starliner, meanwhile, has still not had a fully successful crewed flight.

SpaceX was seen as something of an upstart at the time the contract was awarded, so the outcome shows how much the landscape has shifted in the space sector. It’s also a vote in favour of the iterative, agile processes that Space X adopts, versus the more traditional, linear development processes at Boeing.

Boeing’s reputation for safety and reliability took a massive hit with the two fatal crashes of its 737 Max aircraft. According to a Congressional committee report from 2020, the accidents happened against a background of financial pressure to compete with Airbus’ relatively new A320neo family of aircraft.

This pressure “resulted in extensive efforts to cut costs” and maintain the 737 Max program schedule, the report said. The committee identified several instances where “the desire to meet these goals and expectations jeopardised the safety of the flying public”. Nevertheless, Boeing still managed to spend several billion dollars buying back shares, which can boost a company’s share price, among other things.

Boeing engineers were concerned about pressures within the company and their effects on safety. These worries extended to the development of the Maneuvering Characteristics Augmentation System (MCAS), an onboard system intended to prevent stalling by adjusting the aircraft’s angle automatically. However, the system was initially omitted from aircraft documentation. Pilots who were not familiar with the system didn’t know how to override it, leading to the fatal accidents.

In response to the Congressional report, a Boeing spokesperson said in a statement: “We have learned many hard lessons as a company from the accidents…as this report recognises, we have made fundamental changes to our company as a result, and continue to look for ways to improve.”

Faced with a public outcry after the accidents, Boeing made adjustments to its safety management systems and supply chain quality controls. It also added safety goals as a feature of its employee compensation processes and is generally trying to shift its culture to emphasise safety. There is also more oversight by the Federal Aviation Administration.

Safety culture

The partial failure of Starliner’s mission doesn’t help Boeing’s effort to bounce back from its problems. The company’s reputation has not been irreparably damaged, however. Boeing can recover and is taking the right initiatives to re-emphasise a safety culture – something that’s crucial to its business going forward.

But recovering trust while upholding financial performance can take years. Boeing has lost US$32 billion (£24 billion) since 2019. While losses narrowed in 2023, figures for the last two quarters have not been encouraging with respect to returning to profit. Boeing has a strong order book, but the company needs to find ways to balance efficiency and profitability without compromising safety.

For now, the future of Nasa’s Commercial Crew Program, to transport astronauts to and from the space station, is secure. Nasa can lean more on SpaceX, as it is doing to return the stranded astronauts.

Other companies such as Sierra Space are also developing spacecraft that could, in future, undertake the safe transport of humans to and from space. It’s quite possible that Nasa could eventually partner with these companies for its future needs.

The US space agency prefers to have more than one supplier in crucial services such as this, so that it has flexibility when needed. It’s also preferable in case something goes wrong with one of the vehicles, something known as having “redundancy”.

The ISS is expected to be decommissioned in 2030, when it will reach the limits of its useful life. Nasa is likely to support Boeing’s continued involvement with the Commercial Crew Program given the sunk costs of the contract and Nasa’s need to have more than one supplier.

Yet, even after the ISS is commanded to burn up over the Pacific Ocean, there will probably be commercially owned space stations that require vehicles to transport astronauts. However, both Boeing’s Starliner and SpaceX’s Crew Dragon spacecraft spent more than a decade in development. So while other companies are waiting in the wings, their vehicles are not going to materialise immediately.

Nasa is also building a space station in orbit around the Moon, called Gateway. This is part of Nasa’s Artemis programme. The space agency’s Orion spacecraft will fulfil the crew transport role at first, but there could be a place for commercial providers further down the road.

The Artemis programme has the objective of returning humans to the Moon this decade and Gateway will be central to lunar operations. Nasa could also launch missions to other destinations in deep space from this lunar space station.

Boeing may or may not choose to be a part of this bold new era in spaceflight. But it will need to fully implement the significant changes necessary to rebuild trust and recover from a challenging few years.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

A file photo of Barry Wilmore and Sunita Williams on Starliner
| Photo Credit: AFP/NASA

The two astronauts stuck at the International Space Station since June welcomed their new ride home with Sunday’s (September 29, 2024) arrival of a SpaceX capsule.

SpaceX launched the rescue mission on Saturday (September 28, 2024) with a downsized crew of two astronauts and two empty seats reserved for Barry Wilmore and Sunita Williams, who will return next year. The Dragon capsule docked in darkness as the two craft soared 265 miles (426 kilometers) above Botswana.

NASA switched Mr. Wilmore and Ms. Williams to SpaceX following concerns over the safety of their Boeing Starliner capsule. It was the first Starliner test flight with a crew, and NASA decided the thruster failures and helium leaks cropped up after liftoff were too serious and poorly understood to risk the test pilots’ return. So Starliner returned to Earth empty earlier this month.

The Dragon carrying NASA’s Nick Hague and the Russian Space Agency’s Alexander Gorbunov will remain at the space station until February, turning what should have been a weeklong trip for Mr. Wilmore and Ms. Williams into a mission lasting more than eight months.

Two NASA astronauts were pulled from the mission to make room for Mr. Wilmore and Ms. Williams on the return leg.

“I just want to say welcome to our new compadres,” Ms. Williams, the space station commander, said once Mr. Hague and Mr. Gorbunov floated inside and were embraced by the nine astronauts awaiting them.

Mr. Hague said it was a smooth flight up. “Coming through the hatch and seeing all the smiles, and as much as I’ve laughed and cried in the last 10 minutes, I know it’s going to be an amazing expedition,” he said.

NASA likes to replace its station crews every six months or so. SpaceX has provided the taxi service since the company’s first astronaut flight in 2020. NASA also hired Boeing for ferry flights after the space shuttles were retired, but flawed software and other Starliner issues led to years of delays and more than $1 billion in repairs.

Starliner inspections are underway at NASA’s Kennedy Space Center, with post-flight reviews of data set to begin this week.

“We’re a long way from saying, ‘Hey, we’re writing off Boeing,’” NASA’s associate administrator Jim Free said at a pre-launch briefing.

The arrival of two fresh astronauts means the four who have been up there since March can now return to Earth in their own SpaceX capsule in just over a week, bringing the station’s crew size back down to the normal seven. Their stay was extended a month because of the Starliner turmoil.

Although Saturday’s (September 28, 2024) liftoff went well, SpaceX said the rocket’s spent upper stage ended up outside its targeted impact zone in the Pacific because of a bad engine firing. The company has halted all Falcon launches until it figures out what went wrong.was extended a month because of the Starliner turmoil.

Washington:

The SpaceX crew that will ferry back two astronauts stranded on the International Space Station docked with the orbiting laboratory Sunday, a live stream of the mission showed.

The Falcon 9 rocket took off at 1:17 pm (1717 GMT) from Cape Canaveral, Florida on Saturday, with the Crew-9 mission on a Dragon spacecraft making contact with the ISS at 5:30 pm Sunday.

After docking was completed, NASA astronaut Nick Hague and Russian cosmonaut Alexander Gorbunov boarded the station just after 7:00 pm, embracing their floating colleagues on the space station.

“What a fabulous day it was today,” NASA deputy administrator Pam Melroy said at a news conference.

When Hague and Gorbunov return from the space station in February, they will bring back two space veterans — Butch Wilmore and Suni Williams — whose stay on the ISS was prolonged for months due to problems with their Boeing-designed Starliner spacecraft. 

The newly developed Starliner was making its first crewed flight when it delivered Wilmore and Williams to the ISS in June.

Welcome, #Crew9! After floating through the Dragon’s hatch, our new arrivals join the crew aboard the @Space_Station. They’ll spend five months conducting @ISS_Research and maintenance on the orbiting lab. pic.twitter.com/DJX7f9vxlg

— NASA (@NASA) September 29, 2024

They were supposed to be there for only an eight-day stay, but after problems with the Starliner’s propulsion system emerged during the flight there, NASA was forced to weigh a radical change in plans.

After weeks of intensive tests on the Starliner’s reliability, the space agency finally decided to return it to Earth without its crew, and to bring the two stranded astronauts back home on SpaceX’s Crew-9 mission.

SpaceX, the private company founded by billionaire Elon Musk, has been flying regular missions every six months to allow the rotation of ISS crews.

But the launch of Crew-9 was postponed from mid-August to late September to give NASA experts more time to evaluate the reliability of the Starliner and decide how to proceed.  

It was then delayed a few more days by the destructive passage of Hurricane Helene, a powerful storm that roared into the opposite side of Florida on Thursday.

In total, Hague and Gorbunov will spend some five months on the ISS; and Wilmore and Williams, eight months.

In all, Crew-9 will conduct some 200 scientific experiments. 

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

In this image from video provided by NASA, the empty Boeing Starliner capsule floats down towards White Sands Missile Range in New Mexico late Friday, Sept. 6, 2024, after undocking from the International Space Station.
| Photo Credit: AP/NASA

Boeing’s beleaguered Starliner returned to Earth on Saturday (September 7, 2024) without the astronauts who traveled in it to the International Space Station, after NASA deemed the risk too great.

The gumdrop-shaped capsule landed gently at the White Sands Space Harbor in New Mexico at approximately 0401 GMT, its descent slowed by parachutes and cushioned by airbags, having departed the ISS around six hours earlier.

After months of turmoil over its safety, Boeing’s new astronaut capsule departed the International Space Station on Friday (September 6, 2024) without its crew and headed back to Earth.

NASA’s two test pilots stayed behind at the space station — their home until next year — as the Starliner capsule undocked 260 miles (420 kilometres) over China, springs gently pushing it away from the orbiting laboratory. The return flight was expected to take six hours, with a nighttime touchdown in the New Mexico desert.

“She’s on her way home,” astronaut Suni Williams radioed after Starliner exited

Ms. Williams and Butch Wilmore should have flown Starliner back to Earth in June, a week after launching in it. But thruster failures and helium leaks marred their ride to the space station.

NASA ultimately decided it was too risky to return the duo on Starliner. So the fully automated capsule left with its empty seats and blue spacesuits along with some old station equipment. SpaceX will bring the duo back in late February, stretching their original eight-day mission to more than eight months.

(With inputs from AP)

In this screen grab from a NASA livestream, the Boeing Starliner spacecraft can be seen pulling away from the International Space Station for its unmanned return to the surface of Earth on September 6, 2024.
| Photo Credit: AFP

After months of turmoil over its safety, Boeing’s new astronaut capsule departed the International Space Station on Friday (September 6, 2024) without its crew and headed back to Earth.

NASA’s two test pilots stayed behind at the space station — their home until next year — as the Starliner capsule undocked 260 miles (420 kilometres) over China, springs gently pushing it away from the orbiting laboratory. The return flight was expected to take six hours, with a nighttime touchdown in the New Mexico desert.

“She’s on her way home,” astronaut Suni Williams radioed after Starliner exited

Ms. Williams and Butch Wilmore should have flown Starliner back to Earth in June, a week after launching in it. But thruster failures and helium leaks marred their ride to the space station.

NASA ultimately decided it was too risky to return the duo on Starliner. So the fully automated capsule left with its empty seats and blue spacesuits along with some old station equipment. SpaceX will bring the duo back in late February, stretching their original eight-day mission to more than eight months.

Boeing’s first astronaut flight caps a journey filled with delays and setbacks. After the space shuttles retired more than a decade ago, NASA hired Boeing and SpaceX for orbital taxi service. Boeing ran into so many problems on its first test flight with no one aboard in 2019 that it had to repeat it. The 2022 do-over uncovered even more flaws and the repair bill topped $1 billion.

SpaceX’s crew ferry flight later this month will be its 10th for NASA since 2020. The Dragon capsule will launch on the half-year expedition with only two astronauts since two seats are reserved for Wilmore and Williams for the return leg.

As veteran astronauts and retired Navy captains, Mr. Wilmore and Ms. Williams anticipated hurdles on the test flight. They’ve kept busy in space, helping with repairs and experiments. The two are now full-time station crew members along with the seven others on board.

Even before the pair launched on June 5, Starliner’s propulsion system was leaking helium. The leak was small and thought to be isolated, but four more cropped up after liftoff. Then five thrusters failed. Although four of the thrusters were recovered, it gave NASA pause as to whether more malfunctions might hamper the capsule’s descent from orbit.

Boeing conducted numerous thruster tests in space and on the ground over the summer, and was convinced its spacecraft could safely bring Wilmore and Williams home. But NASA disagreed and opted for SpaceX.

A minute after separating from the space station, Starliner’s thrusters could be seen firing as the white, blue-trimmed capsule slowly backed away. NASA Mission Control called it a “perfect” departure.

Flight controllers planned more test firings of the capsule’s thrusters following undocking. Engineers suspect the more the thrusters are fired, the hotter they become, causing protective seals to swell and obstruct the flow of propellant. They won’t be able to examine any of the parts; the section holding the thrusters will be ditched just before reentry.

NASA’s commercial crew program manager Steve Stich said earlier this week that teams have been so focused on Starliner’s return that they’ve had no time to think about what’s next for Boeing. He said the space agency remains committed to having two competing U.S. companies transporting astronauts.

New Delhi:

NASA, on Saturday, announced that Boeing’s Starliner capsule will return empty from the International Space Station (ISS), citing ongoing propulsion system problems. This latest development adds to Boeing’s woes, with estimated losses in the Starliner program exceeding $1 billion, reported CNBC.

Astronauts Butch Wilmore and Sunita Williams will now return on Elon Musk’s SpaceX’s Crew-9 vehicle in February 2025, after a six-month extended stay on the ISS. The original nine-day test flight was delayed due to issues with Starliner’s thrusters.

A “technical disagreement” between NASA and Boeing led to the decision, with NASA prioritising safety and choosing SpaceX for the return mission.

“Boeing has worked very hard with NASA to get the necessary data to make this decision,” NASA Administrator Bill Nelson said on Saturday. “We want to further understand the root causes and understand the design improvements so that the Boeing Starliner will serve as an important part of our assured crew access to the ISS.” Mr Nelson stressed that test flights like the Starliner mission are “neither safe, nor routine.”

Following the decision, NASA will conduct an additional phase of its Flight Readiness Review to determine the optimal time to bring the empty Starliner capsule back to Earth. 

Despite Boeing’s assurances that Starliner was safe for emergency crew return, NASA disagreed. Mr Nelson expressed support for Boeing, stating he was “100% certain” that Starliner would launch with a crew again in the future. Boeing also reaffirmed its commitment to safety, saying it would execute the mission as determined by NASA and prepare for a safe uncrewed return. 

In a statement on X, Boeing said, “We continue to focus, first and foremost, on the safety of the crew and spacecraft. We are executing the mission as determined by NASA, and we are preparing the spacecraft for a safe and successful uncrewed return.”

Ken Bowersox, NASA associate administrator, said NASA officials were unanimous in their decision to choose SpaceX to bring the crew home. Meanwhile, SpaceX will bring two astronauts along on its Crew-9 vehicle – instead of the four who were originally planned to go – to make room for Wilmore and Williams.

Boeing’s Starliner capsule, ‘Calypso’, has been docked at the International Space Station since June, with its mission extended indefinitely due to ongoing thruster failures. The Starliner crew flight test, intended to be a final milestone for Boeing, has instead become a major setback. 

Story so far: Veteran American astronauts Sunita Williams and Barry (Butch) Wilmore, are still docked with the International Space Station (ISS) since June 6 after facing delays, space debris threats, helium leaks and technical glitches on the Starliner spacecraft on which they travelled.

The U.S Space Agency — National Aeronautics and Space Administration (NASA) — held a ‘space-to-earth’ news conference with the two astronauts on July 10 to receive an update on their mission’s progress. Both astronauts said they ‘felt confident’ that they could return to Earth on Starliner itself.

Also read | How Boeing can bring NASA’s Sunita Williams, Barry Wilmore back to Earth

“I have a real good feeling in my heart that this spacecraft will bring us home, no problem,” said Ms. Williams, while Mr. Wilmore said, “That mantra you’ve heard, failure is not an option.” He added that both crew members were staying on the ISS to test the spacecraft

NASA along with the space capsule’s manufacturer Boeing is evaluating Starliner’s propulsion system and the five small helium leaks in the service module. The team is conducting ground tests on identical thrusters at New Mexico’s White Sands Missile Range while another investigation is underway at NASA’s Marshall Space Flight Center in Alabama to determine why the propulsion system’s seal failed, leading to helium leaks.

The continued delay in Ms. Williams and Mr. Wilmore’s safe return, which was initially scheduled to begin on June 18, has piqued concerns across the world, including India. Apart from Ms. Williams and Mr. Wilmore, NASA astronauts Michael Barratt, Matt Dominick, Tracy C. Dyson, Jeanette Epps and Russian Cosmonauts Nikolai Chub, Alexander Grebenkin, and Oleg Kononenko are aboard the ISS.

Here’s a look at the attempted launches, what went wrong, and current efforts for the crew’s safe return

Starliner’s attempted launches and success

Sunita Williams, 58, is the pilot of NASA’s Crew Flight Test mission aboard Boeing’s Starliner space capsule. The mission is a joint venture between NASA and American private space players to open up commercial travel to low-Earth orbits and the ISS to more people for scientific and commercial purposes.

United Launch Alliance, a joint venture by Boeing and Lockheed Martin manufactured the Atlas V rocket which transported the astronauts via Boeing’s space capsule Starliner to the ISS. With this, NASA will have a second space capsule option (apart from SpaceX’s Crew Dragon), which has a crew module which can house up to seven astronauts and a non-reusable service module which houses the equipment and systems (air, temperature controls, water supply etc) needed for a stay in space.

The first crewed test flight of Starliner with the above-mentioned astronauts was scheduled for May 6 for a week-long stay at the ISS. However, the flight was scrapped less than two hours before the launch after an issue was detected in an oxygen relief valve of the rocket’s second stage. All launch activities were suspended and the flight was postponed to May 17.

A helium leak was detected in a thruster in Starliner’s service module, further postponing the launch to June 1. On that day, the ground launch sequencer, the computer which launches the rocket, triggered an automatic hold stopping the countdown clock three minutes fifty seconds before the launch.

On June 5, Starliner was finally launched successfully from NASA’s Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida and the two astronauts docked with the forward-facing port of the ISS. During their week long stay, the astronauts were tasked with verifying if Starliner was performing as intended by conducting tests on the various control systems and manoeuvring the thrusters. Prior to take-off, a small helium leak was noticed in the space capsule’s propulsion system but not deemed serious.

What went wrong?

En-route to the ISS, four more small helium leaks sprung up. Both NASA and Boeing officials reviewed flight data to find out the cause of the leaks. On June 6, NASA’s Commercial Crew Program manager Steve Stich admitted that similar thruster issues were revealed during the spacecraft’s uncrewed test flight in 2022, adding, “thought we had fixed that problem,” at a press conference.

The undocking and return journey of Starliner, which was scheduled for June 18, was postponed to June 22, then June 25 and later to July 2.

Mr. Stich opined that thruster issues may have been caused overheating when fuel was burned during the space capsule’s rendezvous with the ISS. According to CNN, the Starliner’s service module has 28 reaction control thrusters, of which five have failed during flight. Four were brought back online eventually.

The Starliner, which had its first uncrewed Orbital test flight in 2019, faced a software glitch, leaving the space capsule in the wrong orbit before it returned to ground without docking with the ISS. In 2022, the space capsule successfully conducted its first uncrewed test flight when it docked with the ISS and then undocked four days later to return to Earth. This flight too faced issues with the thrusters.

What is causing the delay?

Apart from technical issues, the crew also faced a debris collision threat on June 28. The US Space Command alerted the six astronauts onboard the ISS to execute ‘safe haven’ procedures i.e. crew members board the spacecraft they arrived in, in case an emergency departure is needed. This was necessitated after a defunct Russian satellite (RESURS-P1) broke into more than 100 pieces of debris in an orbit near the ISS. Ms. Williams and Mr. Wilmore were forced to board the Starliner to take shelter for an hour before they resumed their activities on the ISS.

On July 2, NASA said that the spacecraft was in good shape to remain docked to the ISS for over 45 days (its upper limit), giving the ground teams of NASA and Boeing time to conduct simulations and tests on the thrusters. Analysis is also underway to determine why several helium leaks have arisen in the capsule, said NASA. Currently, NASA has not set any end date to the mission, making the extension indefinite.

How will the crew return?

In the July 10 press conference, NASA has said, that if absolutely necessary, Starliner would be capable of returning to Earth – acting as an escape pod. Moreover, NASA also has the option of ferrying Mr. Wilmore and Ms. Williams to Earth aboard Crew Dragon. The SpaceX spaceship transported four astronauts to the ISS in March and is capable of fitting more people in case of an emergency. However, such an option has would be a last resort in case Starliner is deemed non-functional.

But NASA has reiterated its confidence in the Starliner to return the duo, dropping the option of using the Crew Dragon.

Boeing Starliner’s return to Earth from the International Space Station with its first crew of astronauts has been postponed, NASA said on Friday.

NASA did not provide a new date, raising questions about when the mission’s two astronauts will return as more testing and technical issues have created more delays.

The return to earth was previously scheduled for June 26.

The crew of U.S. astronauts, Butch Wilmore and Sunita Williams, lifted off June 5 as a final demonstration to obtain routine flight certification from NASA.

The crewed test of the spacecraft, which has been test-flown to space twice since 2019 without humans aboard, has encountered five failures of its 28 maneuvering thrusters, five leaks of helium that are meant to pressurize those thrusters, and a slow-moving propellant valve that signaled unfixed issues from the past.

The issues and the additional tests NASA and Boeing have had to do call into question when exactly Starliner will be able to fly its crew home, and add to a list of broader problems Boeing faces with its Starliner program. The company has spent $1.5 billion in cost overruns on top of its $4.5 billion NASA development contract.

NASA wants Starliner to become the second US spacecraft capable of ferrying its astronauts to and from the ISS alongside SpaceX’s Crew Dragon, which has been the agency’s primary ride since 2020. Boeing’s Starliner program has struggled with software glitches, design problems, and subcontractor disputes for years.

When Starliner arrived in the space station’s vicinity to dock on June 6, the five thruster failures prohibited the spacecraft from making a close approach until Boeing could implement a fix. The company rewrote software and tweaked some procedures to revive four of them and proceed with docking.

Starliner’s undocking and return to Earth represent the spacecraft’s most complicated phases of its test mission. NASA officials have said they want to better understand the cause of the thruster failures, valve issue, and helium leaks before Starliner embarks on its roughly six-hour return journey.

While just one thruster remains dead in Starliner’s current flight, Boeing encountered four thruster problems during the capsule’s uncrewed return from space in 2022.

According to flight rules established jointly by Boeing and NASA, Starliner’s maneuvering thrusters must, at a minimum, allow for “6-degrees of freedom of control,” and each has one backup thruster, a NASA spokesperson told Reuters.

That could mean at least 12 of the 28 thrusters – most of which are backups – are required for a safe flight, or potentially fewer, as long as the remaining thrusters have one backup and can work together in a way that doesn’t restrict Starliner’s freedom of movement in space.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)