I toured the USS Nautilus, the world's first nuclear-powered submarine. Take a look inside.

Between 1954 and 1980, the USS Nautilus participated in scientific and military operations around the world.

Nautilus, which was commissioned in 1954, hosted the first-ever underwater legislative meeting when 13 members of Congress rode Nautilus in 1955.

Its nuclear power allowed Nautilus to sail under the polar ice cap and become the first ship to traverse the North Pole in 1958 in an expedition known as Operation Sunshine.

Nautilus also participated in the naval blockade of Cuba during the Cuban Missile Crisis in 1962.

The submarine is now a museum operated by the US Navy in Groton, Connecticut, a short distance from the shipyard where it was built.

After 26 years of service, Nautilus was decommissioned in 1980 and recognized as a National Historic Landmark in 1982. It opened to the public as part of the Submarine Force Museum in Groton, Connecticut, in 1986.

In 2021, Nautilus underwent $36 million of preservation work and reopened in 2022.

The Submarine Force Museum is open Wednesday through Monday and is free to visit.

Measuring 3,400 tons with a length of 319 feet, Nautilus is longer than a football field.

I was amazed by the size of the submarine. As I climbed aboard, the deck provided gorgeous views of the Thames River.

The first stop on my self-guided tour was the forward torpedo room, which featured two torpedo tubes with bronze doors.

Here, crew members loaded torpedoes for firing.

Mannequins depicted crew members working in the forward torpedo room.

After the torpedoes were loaded, the tubes were flooded with water. When the command to fire was issued, high-pressure air from the submarine's ejection pump then forced the water and the torpedoes out of the tubes.

The space also included crew bunks.

Signs on the sink and mirror indicated that they were part of the submarine's original equipment.

Doorways on the USS Nautilus were narrow hatches that sailors had to step through.

Handles on top of the doorways provided a grip to hold on to while stepping through.

The next stop on the tour was the wardroom, which functioned as the living and working space for Nautilus' officers.

Nautilus had a crew of 11 officers and 105 enlisted service members.

A panel of instruments along the wardroom's wall indicated Nautilus' depth and speed.

The officers' meals were served from the officers' pantry next to the wardroom.

Officers ate the same meals as the rest of the crew members, but their food was brought up to the officers' pantry via a dumbwaiter to be reheated and served on Navy china.

Past the wardroom, a hallway led to the officers' quarters.

The walls of the narrow hallway were covered in wood paneling.

The hallway featured a display of an 1892 edition of "Twenty Thousand Leagues Under the Sea," a novel by Jules Verne.

The book was gifted to Nautilus' commanding officer, Commander William R. Anderson, in 1957 by the French Navy's chief of staff, Adm. Henri Nomy. The fictional submarine in the book is also named Nautilus.

The officers' staterooms included sinks, small desks, and storage areas.

Fewer beds in a room indicated a higher rank.

The executive officer's stateroom contained another bunk that folded down.

The executive officer, also known as the "XO," was the ship's second-in-command.

The commanding officer enjoyed the privilege of the ship's only private room.

The commanding officer used the stateroom as a workspace and living quarters.

A crew member known as the yeoman managed all of Nautilus' paperwork from a small office.

The yeoman managed the ship's correspondence and personnel records.

The attack center was Nautilus' battle station.

The attack center contained periscopes to spot enemy ships and the controls to aim and fire torpedoes.

Crew members used a line-of-sight diagram to calculate the range and direction for firing torpedoes.

On the diagram, Nautilus is represented by the bottom ship, and the top ship represents the target.

Torpedoes were fired using this firing panel next to the line-of-sight diagram.

The torpedo firing key, which was used to deploy the torpedoes, was indicated with a blue sign on the firing panel.

An alarm panel in the attack center had various alerts for different emergencies.

The alarms were color-coded for different scenarios:

• Yellow: a fire or casualty
• Red: flooding or a collision
• Green: submerging or emergency surfacing
• Pink: a power plant casualty

A small arms locker contained guns kept under lock and key.

The guns were used for security while the submarine was in port.

The sonar room featured equipment used to listen for and detect other vessels.

Sonar stands for "sound navigation and ranging." Active sonar emitted sound pulses to locate targets, while passive sonar listened for underwater activity.

Nautilus featured the first-ever set of stairs on a submarine.

Before that, ladders were used to climb from one level to another.

In the control room, sailors controlled the ship's depth, tilt, and speed.

Commands were issued in the control room by a crew member known as the diving officer of the watch, who received orders from the attack center.

These levers controlled the flow of water and air in the submarine's main ballast tanks.

When the main ballast tanks filled with water, the submarine would submerge. When filled with air, the submarine would surface.

A crew member worked in the ESM bay, which stands for "electronic surveillance measures."

The ESM bay's instruments could detect other ships' radars.

Nautilus communicated with other ships from the radio room.

The radio room was located just off the control room on the right.

The crew's mess was the largest common space on the submarine.

Here, crew members ate meals, worked, and spent their recreational time.

One of the museum's displays featured a mannequin wearing an oxygen breathing apparatus, or OBA.

Damage control personnel used OBAs if fires broke out on board while submerged. The hoses on the masks could be attached to the submarine's reserve air supply.

The crew's mess also included a lay services box, which crew members used to celebrate religious holidays.

Since there was no Navy chaplain on board the submarine, crew member volunteers conducted services for various faiths with items from the lay services box.

A window in the floor of the crew's mess provided a look into Nautilus' battery well.

Nautilus was mainly powered by its nuclear reactor, but the battery served as an auxiliary source of power in case of an emergency.

Chief petty officers had the privilege of their own private lounge and living area.

Chief petty officers acted as liaisons between officers and crew members. Their living quarters were sometimes known as the "goat locker."

There are a few possible explanations for the nickname. Chief petty officers used to be in charge of goats that were kept on ships to produce fresh milk. Chief petty officers were also nicknamed "old goats" because they were senior officers who had been in the Navy for a long time.

All meals on board Nautilus were cooked in the galley.

A window connected the galley to the scullery, where crew members washed dishes.

The tour ended with more crew bunks.

Nautilus had two crew quarters, one at the front of the submarine and one at the back.

Inside the museum building, I perused exhibits about Nautilus and submarine history, including real working periscopes.

I swiveled the periscope until I could see my car sitting in the museum's parking lot, which was pretty cool.

Nautilus' notable history serves as a reminder of how quickly maritime technology has continued to advance.

Just over 70 years after Nautilus was commissioned as the first nuclear-powered submarine in the world, all of the US Navy's submarines are now nuclear-powered, according to the Department of Defense.