Helicopter Sea Combat Squadron Nine's primary mission is to employ the versatility of the MH-60S helicopter to support the strike group commander's objectives, with emphasis on Anti-Surface Warfare (ASUW), Combat Search and Rescue (CSAR), support of Special Operations, and Vertical Replenishment (VERTREP).

HSC-9 was established as Helicopter Antisubmarine Squadron Three (HS-3) on 18 June 1952, at the Naval Air Facility Elizabeth City, North Carolina.

Astronauts Carpenter, Grissom, Young, Collins, Gordon, Conrad, McDivitt, Scott, and Schweickart all ended their space journeys with rides aboard HS-3 helicopters.

In the early 1970s, the squadron participated in the relief of Tunisian flood victims, rescuing or relocating 630 people while transporting over 43,000 pounds (20,000 kg) of food and medical supplies.

Squadron personnel participated in some of the publicity events leading up to the actual ringing of Forrestal's bell on 4 July 1976.

HS-3 was awarded two Navy Unit Commendations for operational accomplishments and outstanding maintenance efforts during the 1985-86 Mediterranean and Indian Ocean deployment on board Saratoga.

In 1990, the Tridents enforced United Nations sanctions against Iraqi trade while deployed on board the Saratoga in the Red Sea.

Preparations for the squadron's 1995 Mediterranean deployment were interrupted when the Tridents were called on to support Operation Uphold Democracy during the military intervention in Haiti.

The Tridents deployed one week after the completion of Uphold Democracy and flew in support of Operation Deny Flight over Bosnia-Herzegovina.

During this deployment, HS-3 also flew the first actual CSAR mission by an HS squadron since the Vietnam era to search for the crew of a downed French Mirage fighter.

Once a cease-fire was agreed upon, Theodore Roosevelt transited the Persian Gulf to support maritime interdiction operations and enforce no-fly zones over southern Iraq.

In September 2008, after completing a lengthy training cycle, the Tridents deployed aboard Theodore Roosevelt to the Arabian Sea in support of combat operations in Afghanistan.

On 16 April 2009, the Tridents returned home to Naval Air Station Jacksonville, Florida, from their final cruise as a Helicopter Anti-Submarine Squadron.

On 13 January 2010, the Tridents sent two helicopters in support of Operation Unified Response, providing humanitarian aid and disaster relief following the devastating Haiti earthquake.

The Tridents also brought ashore over 556,000 pounds (252,000 kg) of sustainment supplies and made 1,300 passenger transfers in support of the Operation.