MARTINSBURG, West Virginia — A Maryland husband and wife accused of trying to sell U.S. nuclear submarine secrets to a foreign country were ordered to remain in jail Tuesday, pending a hearing later this week.

Jonathan and Diana Toebbe of Annapolis made short, separate appearances before Magistrate Judge Robert Trumble in the federal courthouse, not far from where they were arrested Saturday. Authorities say they were taken into custody during their latest alleged attempt to “dead drop” information to a person they thought was their foreign intelligence service handler – but who was in truth an undercover FBI agent.

The Toebbes face the prospect of life in prison if convicted of violating the Atomic Energy Act by sharing “restricted data” about the nuclear propulsion systems for Virginia-class submarines, which are cutting-edge cruise-missile carriers that cost $3 billion apiece to build.

The arrests shocked the quiet Annapolis neighborhood where the couple lived with their two children and dogs. Diana Toebbe, 45, had worked for years as an English teacher at the private Key School, which has placed her on leave.

Jonathan Toebbe, 42, who once wore a Navy uniform as a nuclear engineer, appeared in court wearing a bright-orange prison jumpsuit with the word “Inmate” on the back. His hands were shackled to chains around his hips, so when the judge ordered him to raise his right hand, he could lift it only at his waist.

No lawyer appeared beside Toebbe, and Trumble said based on his financial declaration, the court would appoint an attorney for him.

After U.S. marshals escorted Toebbe out of the courtroom, his wife shuffled in wearing a similar jumpsuit and chains, with additional cuffs around her feet. Asked if the statement she signed about her finances was correct, she replied, “to the best of my knowledge, which is very limited.” She also appeared without a lawyer, and the judge said one would be appointed to represent her.

Trumble ordered the pair to remain in custody until a detention hearing Friday, when prosecutors say they will ask the judge to keep them in jail pending their trial.

Authorities have charged that both Toebbes are flight risks. The criminal complaint filed against them cites an email allegedly written by Jonathan Toebbe, which says they had stashed passports and cash in case they needed to flee.