In the summer of 1974, a vessel called the Hughes Glomar Explorer sat in the middle of the Pacific Ocean, about 1,500 miles northwest of Hawaii, and lowered a steel claw the size of a large house three miles to the ocean floor. It was supposedly a deep-sea mining ship, operated by Howard Hughes's company. It was actually a CIA operation. It was trying to lift an entire Soviet submarine from the bottom of the sea.

This was Project AZORIAN. It was, by any measure, one of the most audacious covert operations ever attempted — and its results, still partially classified more than fifty years later, tell you something important about what American intelligence was willing to attempt at the height of the Cold War.

The Submarine and the Window

In March 1968, the Soviet Golf II-class ballistic missile submarine K-129 sank in the Pacific approximately 1,560 miles northwest of Hawaii. The Soviets searched extensively but never found it. The US Navy, using its own hydroacoustic monitoring system (SOSUS), had detected the sinking and had a rough location. In late 1968, the Navy dispatched the deep-submergence vehicle USS Halibut, under a classified mission, to locate and photograph the wreck. Halibut found K-129 at a depth of approximately 16,500 feet and photographed it extensively.

What those photographs showed made the intelligence community intensely interested in recovery. K-129 carried three SS-N-4 nuclear ballistic missiles and, reportedly, nuclear torpedoes. It also carried cryptographic equipment, cipher materials, and communications gear that, if recovered intact, would give American signals intelligence analysts an extraordinary window into Soviet naval communications. The submarine had broken into sections on the bottom, but a significant portion of the hull appeared reasonably intact.

The CIA, under Director Richard Helms and later William Colby, developed the recovery concept in partnership with the Navy. The problem was engineering: nobody had ever lifted anything from 16,500 feet of ocean. No equipment existed to do it. The entire apparatus — the ship, the lifting system, the capture vehicle — would have to be designed and built from scratch, in secret, at a cost that would eventually reach approximately $800 million (roughly $4.5 billion in 2024 dollars).

The Cover Story: Howard Hughes and Deep-Sea Mining

The CIA's solution to the cover problem was characteristically elaborate. In the early 1970s, deep-sea manganese nodule mining was attracting genuine commercial interest, and Howard Hughes — already known as a reclusive billionaire with a documented interest in unusual ventures — was a plausible backer for a heavy-lift deep-ocean vessel. The CIA approached Hughes through intermediaries. Hughes, who had existing contractual relationships with the agency, agreed.

The Hughes Glomar Explorer was built by Sun Shipbuilding in Chester, Pennsylvania, and delivered in 1973. It was 618 feet long, displaced 63,000 tons, and contained a large internal compartment called the "moon pool" — a flooded well in the center of the hull through which the lifting mechanism could be lowered. The lifting system, called the Heavy Lift System, used a latticed pipe string built up section by section from aboard the ship, terminating in a massive claw-like capture vehicle called the Clementine.

Every person working on the program — engineers at Global Marine (the ship operator), construction workers, ship's crew — signed secrecy agreements and was briefed into the program only as far as their specific role required. Many believed the mining cover story; others knew something classified was happening but not what. The total workforce across all contractors ran to several thousand people. Keeping the program secret from that many people, over years of construction and preparation, was itself a significant counterintelligence achievement.

"We were building something nobody had ever built, to do something nobody had ever done, on a cover story that was itself technically plausible," a former program engineer told journalist Sherry Sontag, whose 1998 account Blind Man's Bluff drew on declassified records and interviews.

The Lift: Summer 1974

The Glomar Explorer arrived on station in late June 1974. The Soviet Navy sent a surveillance vessel, the SB-10, to observe — the Soviets were aware of the ship's presence and presumably suspicious of the mining cover, though apparently uncertain about its actual purpose. The CIA's operational security held: the Soviets monitored but did not interfere.

The lift operation began on July 4, 1974. The pipe string, assembled section by section through the moon pool over several days, reached the ocean floor and the Clementine capture vehicle made contact with the K-129 wreckage. The lift began.

At approximately 6,700 feet of water depth — less than halfway up — the Clementine broke apart. Engineering stress analyses prepared during planning had identified the connection points between capture vehicle sections as potential failure points under the load of the submarine hull; those points failed under actual conditions. A portion of the K-129 — estimated at roughly one-third of the section the CIA had targeted — was recovered. The remainder fell back to the ocean floor.

What Was Recovered — and What Wasn't

The CIA has never fully disclosed what was recovered from K-129. What is known from declassified documents and confirmed in a 2010 CIA historical review is that the recovered section did not include the ballistic missile compartment or the cryptographic equipment that were the primary intelligence targets. The recovered section reportedly contained the remains of six Soviet sailors, who were given a burial at sea conducted in both English and Russian. A film of the ceremony was provided to the Russian government in 1992.

Whether any cryptographic materials, torpedo components, or nuclear materials were recovered in the partial lift remains disputed and partially classified. The CIA's 2010 declassified summary acknowledges that "some intelligence value" was obtained. Analysts familiar with the program, quoted in various accounts, suggest the haul was modest relative to the program's cost and ambition.

The Leak and the Cover's End

In early 1975, the Los Angeles Times and then other publications began reporting that the Glomar Explorer was a CIA front and that the operation had targeted a Soviet submarine. The story had leaked through a combination of a 1974 break-in at the Los Angeles offices of Summa Corporation (Hughes's company), during which documents related to the program were stolen, and subsequent efforts by the thieves to sell information. By the time Seymour Hersh published a detailed account in the New York Times in March 1975, the story was effectively out.

The CIA requested a news blackout, which held briefly. The government's argument — that Soviet knowledge of the partial success might compromise ongoing intelligence value — was plausible but contested. When the story fully broke, the operational cover for the Glomar Explorer was finished.

The ship itself went on to a second career as a legitimate deep-sea drilling vessel, leased to various operators. The phrase "Glomar response" — the refusal to confirm or deny the existence of a document or record — entered legal usage from the CIA's response to Freedom of Information Act requests about the program: "We can neither confirm nor deny." Courts have upheld the Glomar response doctrine in national security cases ever since.