The National Transportation Safety Board has announced a third mission to the wreckage of the containership El Faro. The mission, which embarked last Friday, has as its primary objective to retrieve the sunken cargo ship’s voyage data recorder (VDR).

El Faro, a U.S.-flagged cargo ship, sank during Hurricane Joaquin October 1, 2015. The El Faro wreckage was positively identified on November 1, 2015, during the NTSB’s initial mission. The voyage data recorder that was located on April 26 in about 15,000 feet of water near the Bahamas.

The Military Sealift Command’s fleet ocean tug USNS Apache is expected to arrive at the accident site around August 9. Along with the NTSB, the U.S. Coast Guard, the U.S. Navy, and Phoenix International are joining the recovery effort, using CURV-21, a deep ocean remotely operated underwater vehicle to retrieve the VDR and conduct additional wreckage documentation.

“We’re hopeful that the information contained in the voyage data recorder will provide insights into the circumstances of the ship’s sinking,” said Brian Curtis, acting director of the NTSB Office of Marine Safety.

Following the El Faro’s sinking, the NTSB conducted an initial search mission to locate the vessel and conduct an initial survey of the debris field in October and November of 2015. The data collected during that mission was used by investigators to plot “high probability” search zones for the second mission in April, which resulted in the location of the mast and VDR. The wreckage is in approximately 15,000 feet of water, about 41 miles northeast of Crooked Islands, Bahamas.

USNS Apache is expected to arrive at Mayport, Florida, between August 16 and August 20, following completion of the mission.

The cost for this mission is expected to be $500,000, bringing the total for the three missions to approximately $3 million.