The USS Theodore Roosevelt aircraft carrier left a naval base in Guam for the first time since a coronavirus outbreak on the vessel diverted it to the territory in late March.
The Navy said that the aircraft carrier entered the Philippine Sea on Thursday "to conduct carrier qualification flights for Carrier Air Wing 11."
The ship was diverted to Guam and arrived there March 27 after an outbreak of the coronavirus that causes the disease COVID-19 aboard the ship.
The aircraft carrier also became a center of a controversy involving its captain, Capt. Brett Crozier, who was relieved of command April 2 after sending a strongly worded letter to Navy leadership about his concerns, which was leaked to the media.
That decision to relieve the captain is under review, and Crozier could be reinstated.
The ship was moored in Guam so everyone on board, about 5,000 people, could be tested.
Around 1,140 personnel have tested positive for the coronavirus illness, an official said, although some have recovered. About 700 people who have tested positive remain on Naval Base Guam, including 14 sailors who tested positive again after recovery, a Defense official said Wednesday.
The Navy said that nearly 4,000 crewmembers were moved off the ship, which has been cleaned "from bow to stern," and that enough crewmembers to operate the carrier have been returned from quarantine.
The ship's current commanding officer, Capt. Carlos Sardiello, said in a statement that the mission it is now on, carrier qualification, needs fewer personnel than other missions.
"Bringing fewer Sailors on board will enable enhanced social distancing while underway," Sardiello said in a statement.
A Defense official told NBC News that the carrier qualifications that the USS Theodore Roosevelt will conduct while at sea allow Carrier Air Wing 11 to disembark while at sea and conduct refresher trainings including landings on Andersen Air Force Base in Guam.
The mission also occurred after a simulation in which other safety measures in addition to social distancing were practiced, the Navy said. Those mitigation measures include wearing masks, medically supervising the crew, adjusted meal times and other steps.
There are more than 3,300 sailors conducting this mission, the official said, and they met a criteria before they could return to the ship including being in isolation for a minimum of 14 days, having no symptoms for 3 days with no medicine, and two exit tests where a sailor tests negative.
The Theodore Roosevelt is expected to be at sea for approximately two weeks.