So she was surprised when she noticed that her estranged spouse still seemed to know things about her spending. Had she bought a car? How could she afford that?
Ms Worden put her intelligence background to work, asking her bank about the locations of computers that had recently accessed her bank account using her login credentials.
The bank got back to her with an answer: one was a computer network registered to Nasa.
She was about to be part of Nasa’s first all-female spacewalk. But the couple’s domestic troubles on Earth, it seemed, had extended into outer space.
Ms McClain acknowledged that she had accessed the bank account from space, insisting through a lawyer that she was merely shepherding the couple’s still-intertwined finances.
Ms Worden felt differently. She filed a complaint with the US Federal Trade Commission (FTC) and her family lodged one with Nasa’s Office of Inspector General, accusing Ms McClain of identity theft and improper access to her private financial records.
Investigators from the inspector general’s office have since contacted Ms Worden and Ms McClain, trying to get to the bottom of what may be the first allegation of criminal wrongdoing in space.
“I was pretty appalled that she would go that far. I knew it was not okay,” Ms Worden said.
The five space agencies involved in the space station — from the United States, Russia, Japan, Europe and Canada — have long-established procedures to handle any jurisdictional questions that arise when astronauts of various nations are orbiting Earth together.
But Mark Sundahl, director of the Global Space Law Centre at Cleveland State University, said he was not aware of any previous allegation of a crime committed in space.
Nasa officials said they were also unaware of any crimes committed on the space station.
Ms McClain, now back on Earth, submitted to an under-oath interview with the inspector general last week. She contends that she was merely doing what she had always done, with Ms Worden’s permission, to make sure the family’s finances were in order.
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“She strenuously denies that she did anything improper,” said her lawyer, Rusty Hardin, who added that the astronaut “is totally cooperating”.
Ms Hardin said the bank access from space was an attempt to make sure that there were sufficient funds in Ms Worden’s account to pay bills and care for the child they had been raising.
Ms McClain had done the same throughout the relationship, he said, with Ms Worden’s full knowledge. Ms McClain continued using the password that she had used previously and never heard from Ms Worden that the account was now off limits, he added.
A complaint involving bank access from the space station is just one of a number of complex legal issues that have emerged in the age of routine space travel, issues that are expected to grow with the onset of space tourism.
One potential issue that could arise with any criminal case or lawsuit over extra-terrestrial bank communications, Ms Sundahl said, is discovery: Nasa officials would be wary of opening up highly sensitive computer networks to examination by lawyers, for example.
But those sorts of legal questions, he said, are going to be inevitable as people spend more time in outer space.
The couple’s dispute revolved largely around Ms Worden’s son, who was born about a year before the two met.
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Ms Worden, who had previously worked at the US National Security Agency, resisted allowing Ms McClain to adopt the child, even after they were married at the end of 2014.
In early 2018, while the couple was still married, Ms McClain went to a local court in the Houston area to ask a judge to grant her shared parenting rights and “the exclusive right to designate the primary residence of the child” if the parties could not reach a mutual agreement, according to records.
She contended that Ms Worden had an explosive temper and was making poor financial decisions, and she wanted the court to “legally validate my established and deep parental relationship” with the young boy.
Around the same time, Ms McClain apparently posted official Nasa photos — now deleted — on her Twitter account, showing herself in her astronaut suit smiling alongside Ms Worden’s son.
“The hardest part about training for space is the four-year-old I have to leave behind every time I walk out the door,” she wrote at the time.
The social media attention angered Ms Worden further, as she did not want Ms McClain to claim to be the mother of the child.
Later in 2018, Ms Worden filed for divorce after Ms McClain accused her of assault — something Ms Worden denies and said she believed was part of Ms McClain’s bid to get control of the child. The assault case was later dismissed.
Despite the turmoil, Ms McClain portrayed no outward signs of trouble on the space station.
The Spokane, Washington, native was an acclaimed leader with a decorated past — a West Point graduate who became a commissioned army officer and flew more than 800 combat hours in Operation Iraqi Freedom before joining Nasa in 2013.
She remains a lieutenant colonel in the army, and Stars and Stripes reported this week that she is on a list of candidates Nasa is considering to be the first woman on the moon.
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In the days after Ms McClain’s email to Ms Worden, the latter filed a complaint with the FTC, accusing Ms McClain of committing identity theft — though she saw no sign that anyone had moved or made use of the funds in the account.
Ms McClain, meanwhile, was gaining national attention for another reason.
Nasa was promoting the coming milestone of an all-female spacewalk, with Ms McClain set to do work outside the space station with fellow astronaut Christina Koch.
But in a sudden switch a few days before the spacewalk, Nasa scrapped McCain’s role, explaining that there were not enough suits available in the two women’s size.
Saturday Night Live skewered the agency, with actress Aidy Bryant portraying a disappointed Ms McClain with her dreams crushed by poor Nasa planning.
A Nasa spokeswoman, Megan Sumner, said the decision about the spacewalk was not influenced by any allegations about Ms McClain. Ms Sumner declined to comment about the other issues raised by Ms Worden.
The New York Times