Deep in the bowels of the National Aquarium, a more than 230-pound sea turtle named Pegasus gracefully glides in her tank.

Pegasus is majestic, but visitors to the aquarium likely won’t get a glimpse at her. The approximately 40-year-old loggerhead sea turtle is part of the aquarium’s rehabilitation program.

The National Aquarium cares for sea turtles year-round that have been injured by boats or suffer from cold stunning, basically hypothermia for turtles.

“Pegasus washed up on shore unable to really kind of hold her own in the waves, and was just getting tossed around, really lethargic, and there was no real clear injury, which was very strange, but there was some small signs that she was suffering from a blunt force trauma,” said Caitlin Bovery, the rehabilitation manager at the National Aquarium.

Pegasus has been at the aquarium for nearly a year and is being treated for what vets commonly call ‘bubble butt.’

It’s a condition where turtles are unable to regulate air in their bodies and therefore their back-ends float to the surface.

The aquarium has been helping Pegasus recalibrate by attaching weights to her shell to help her adapt to diving under the water again.

The National Aquarium relies on nearly 200 volunteers to care for the six different kinds of sea turtles that are native to U.S. waters.

“Right now I’m cleaning the fecal matter out of her pool, which is a lot, since she's a giant turtle,” said volunteer Theresea Wonder. “We fed her this morning. She has a large diet: squid, fish, shrimp. We also, as volunteers, help assist giving vitamins. For any medical procedures the staff has to do we will restrain the turtles or anything else that they need us to do.”

Medical procedures are a large part of caring for the turtles. Next to Pegasus’s tank is a gigantic pool, large enough to hold a small whale if the aquarium ever needs to.

Right now, it’s filled with about a dozen Kemp’s ridley sea turtles. They are much smaller than Pegasus, and most are juveniles and about a foot long.

Bovery walks down a set of stairs to get to the turtles and is preparing to inject one with its medicine for the day.

This turtle has wounds from being hit by a boat.

“You can see these are starting to form some really nice little scabs,” Bovery says, pointing to the shell. “They're starting to peel really well, and the carapace won't necessarily all be the same color, but it'll kind of fill in with some of that darker gray scar tissue. Their carapace is bone. It's their ribs and their spine fused together, but it's got a very thick layer of keratin, which is like your fingernail over the top, so that it can recover.”

The aquarium also has a separate facility in Baltimore where it keeps other animals. That’s where Kai and Odie reside. They are also Kemp’s ridley sea turtles, but are more fully grown. Odie is two-and-a-half-feet long.

Odie and Kai have injuries that may prevent them from being reintroduced to the wild and could end up staying in rehabilitation or becoming part of an exhibit.

“We've experimented a lot with different devices to give her that ability to dive down and stay down,” said Meredith Meyers-Benson, an assistant curator at the National Aquarium, said of Kai. “We've been attaching weights to her shell, and then we've also tried a prosthetic placement that's weighted to put on the backside of her shell.”

While visitors may be able to look forward to seeing Kai in the aquarium, the goal is to release the turtles into the wild.

In February, the aquarium released 29 Kemp’s ridley and three loggerhead turtles back into the wile at Canaveral National Seashore in Florida.

Bovery says she hopes Pegasus and the other turtles healing at the aquarium will meet the same happy ending.