Astronauts Mark Kelly (right) and twin Scott Kelly (left) will rendezvous at the International Space Station in late February 2011.

Like most twins, Scott Kelly says he and his brother, Mark, shared a lot as kids, they even got jobs together.

"When we were 17 years old we worked for the same ambulance company. I think that at one point we even made pizzas together probably when we were about 15."

Mark Kelly adds that the two also embarked on parallel careers.

"We both became pilots in the navy flying off of aircraft carriers. I flew the A-6 Intruder; Scott, the F-14 Tom Cat and later became test pilots and a lot of test pilots become interested in the space program and we both applied at the same time and we were fortunate enough to be selected."

That were 1996 when the Kelly twin were 32. Since then the men have made multiple space flights, but never together.

NASA's twin brother astronauts are scheduled to meet up at the International Space Station.

That will change early next year when the two astronauts rendezvous at the International Space Station. Scott will be in command when Mark docks aboard a supply mission on the Space Shuttle Endeavor.

Scott says beyond the publicity surrounding their flights - with all those references to the Gemini twins of the ancient Zodiac signs, the brothers know there's work to be done.

"Our focus is completing this mission, doing it successfully. We understand this is a human interest story, but you know our primary focus is doing the job and getting home safely."

The February mission marks the end of NASA's Space Shuttle program.

Endeavor Commander Mark Kelly [bottom center] with crewmates, will make the 36th and perhaps final mission to the International Space Station.

While some critics warn that its shutdown could pose access and supply problems for the International Space Station, Endeavor commander Mark Kelly says it's time for the Space Agency to retire the shuttle and chart new directions.

"We will fly for a long time. It was designed to build a space station and after STS-134, the International Space station will be complete. It has really done its job," he says. "And in order for us to build a new class of rockets and a new spacecraft and to do other things, we are going to have to retire the space shuttle. So this is something we have been planning to do for a long time, for at least six years that has been in the course."

Scott and Mark Kelly say their work in space has been a privilege and both feel it's been an honor to serve their country through the space program. They say their numerous trips to earth orbit have given them a new perspective on the planet.

"One thing that astronaut surprise us is when you flying in the space, when you looking down at the planet, there are no borders. All the political borders between countries don't exist. It makes an impression on you that we are all part of planet earth. The other thing is the atmosphere from the space looks very very thin and fragile," Scott says.

Mark agrees. "Yeah, I agree. When you are in space, and you look at the earth like a big, blue bubble, and you look at the horizon, the atmosphere is a little sliver, it gives you the impression that is pretty thin and fragile. You think about what we all need to do to try to protect it."

When the Kelly twins finally do meet in space next year, crewmembers are not likely to have any problem telling the two identically bald-headed brothers apart. Mark says he'll still be wearing his signature mustache.

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（来源：VOA 编辑：陈丹妮）