The U.S. Air Force Has a Spy Ship — Yes, Ship — in the Persian Gulf

USNS ‘Invincible’ is in the perfect position to track Iranian missiles


The U.S. Air Force quietly keeps a small, inconspicuous spy ship in the Persian Gulf, presumably in order to keep an eye on Iran’s missile launches.

Technically speaking, USNS Invincible—a 224-foot vessel displacing a mere 2,800 tons—belongs to Military Sealift Command, the quasi-civilian branch of the Navy that operates America’s military logistics ship and other specialist vessels.

But Invincible is just a hull—unremarkable, painted white and maintained by 18 civilian contractors. It’s what’s inside and atop the hull that really matters. A sophisticated, dual X- and S-band radar called Gray Star that belongs to the Air Force.

No one says much about Invincible or Gray Star. Military Sealift Command refers to the vessel as a “missile range instrumentation ship” whose job it is to “monitor missile launches and collect data.”

The Air Force’s Intelligence, Surveillance and Reconnaissance Agency, in its official history for 2012, lumps Gray Star in with its sea-based systems that collect “scientific and technical data of foreign military capabilities and systems.”

War Is Boring obtained a copy of the history through the Freedom of Information Act.

The word “Iran” does not appear in any official description of Invincible or Gray Star.

But it’s apparent from the ship’s deployments that she spends most of her time keeping tabs on the regime in Tehran—specifically, Iran’s expanding arsenal of medium-range ballistic missiles.

The Air Force ISR Agency admits that Invincible “typically” deploys to Central Command’s area, which includes the Persian Gulf and Indian Ocean. But there’s not a lot of actual evidence of the ship’s presence overseas. The military seems keen to downplay Invincible’s activities.

In May 2012, Invincible—which has no official home port in the U.S.—passed through the Strait of Hormuz into the Persian Gulf in a convoy of U.S. Navy and British vessels. An official photo depicts the transit.

U.S. Navy photos

Another official photo from November 2012 shows sailors from the destroyer USS Jason Dunham riding in a small boat to visit Invincible somewhere in the Persian Gulf.

And that’s the last official photograph we have of the Air Force spy ship. Military Sealift Command reveals in its official history for 2013 that Invincible sailed to the Mediterranean in May of that year.

But an online ship-tracking service shows that on July 27, 2013, Invincible was back in the Gulf, sailing 50 miles or so northeast of Bahrain, where the U.S. Fifth Fleet maintains its headquarters. After that date, the spy ship disappeared from online location databases.

Tehran is 650 miles from Bahrain’s capital Manama.

We can reasonably assert that Invincible is still in the Persian Gulf. One user of the LinkedIn social media Website claims he was part of Invincible’s crew as recently as December 2013. He lists his location at that time as Bahrain.

And in the fall of 2014, Invincible’s crew shipped a one-ton package back to the U.S. via a commercial freighter. The crew gave its home address as Manama. The package arrived back in America in October.

Which is a strong indicator that the Air Force’s spy ship with her high-tech Gray Star radar is still on duty near Iran, apparently still watching for Tehran’s missile tests.