Ms. Worden’s spouse, Anne McClain, was a decorated NASA astronaut on a six-month mission aboard the International Space Station. 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 Federal Trade Commission and her family lodged one with NASA’s Office of Inspector General, accusing Ms. McClain of identity theft and improper access to Ms. Worden’s 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 O.K.,” Ms. Worden said.