In July, Spc. Thomas Graham, a Rossville resident serving a second tour in Iraq, lost his legs in an explosion that claimed the lives of two other soldiers.

This weekend, after months of rehabilitation at Walter Reed Army Medical Center, he’s in Chattanooga to visit his uncle and spend a few days at Chattacon. The science fiction convention is a chance to catch up with friends and enjoy a break from the hospital, said Spc. Graham, 24.

“I attended it once when I was 19, and that got me seriously into the science fiction convention theme,” he said. “I love science fiction of all kinds.”

Spc. Graham’s uncle, Frank Fry, also of Rossville, helps organize security for the event and said he is enjoying the chance to spend time with the nephew he nearly lost to war.

“We’re lucky he came home,” Mr. Fry said.

Sitting in the gunner’s turret of a Humvee during a patrol Sadr City, Iraq, on July 6, Spc. Graham was about to traverse a notoriously bomb-laden patch of road. Normally, he would have ducked into the vehicle to protect himself, but the seat was set for another soldier.

“The IED went off and pierced the thicker part of the armor, and if I had gone down I would have been dead,” he said. “Instead it severed off both of my legs right below the knee. It killed the driver and the truck commander.”

Days later, as he came to in a Baghdad hospital, one of the surviving members of the tank crew reassured Spc. Graham that he would one day walk again.

“I think to myself, ‘What’s he talking about?’” Spc. Graham recalled. “Then I take the blankets off my legs and see that my feet are gone and my legs are gone.”

Before he called his mother in Colorado, the soldier called his uncle in North Georgia to tell him what had happened and ask for advice on how to break the news to his mother.

“He told me he was coming home, and I said ‘You just got over there a few months ago, what’s going on?” Mr. Fry said.

When Spc. Graham’s plane arrived in the United States, the soldiers on board had a surprise visitor: President Bush stepped onto the aircraft to greet them.

“He stuck around and chatted with a few of us,” Spc. Graham said. The president also planted a kiss on Spc. Graham’s bald head during the visit.

“I thought that was pretty funny,” Spc. Graham said.

Spc. Graham was born in New Jersey and then lived in Colorado before moving to North Georgia after high school. He worked for about a year for Shaw Industries as a fork truck operator, then joined the Army. If he wasn’t so badly injured, he would return to his military career, he said.

“Being an Army tanker is the best job I’ve ever had,” he said.

Now walking with the help of prosthetic legs, Spc. Graham plans eventually to move back to Colorado and buy property where he and his mother will build a two-family house to share. She took months of leave from her job to care for him at Walter Reed, Spc. Graham said.

Mr. Fry, a Marine Corps veteran, said he is proud of his nephew’s determination.

“His attitude is you can’t change the past, so look to the future,” he said. “There’s no use whining and crying about something you can’t change.”