Two rookie astronauts, one a lifelong space fan and the other a born explorer, are gearing up for their first taste of spaceflight when NASA's shuttle Atlantis rockets towards orbit this week.

First-time spaceflyers John "Danny" Olivas and Steve Swanson, along with five fellow crewmates, are due to launch spaceward June 8 aboard NASA's space shuttle Atlantis on a construction mission to the International Space Station (ISS).

"We've got an absolutely fantastic crew," Olivas said in a NASA interview. "I couldn't ask to have a better set of crewmates, and I'm doing the best I can to try and keep up with them."

Olivas and Swanson, both trained spacewalkers, will help deliver a pair of new 17.5-ton trusses and a pair of solar arrays to the starboard side of the ISS during NASA's planned 11-day STS-117 mission.

Of the mission's three planned spacewalks, Olivas will take part in the first and third excursions while Swanson will participate in the second.

"Probably the most exciting thing is going to be the spacewalk, followed by the launch," Swanson told reporters in a preflight interview.

Reaching for space

Olivas hails from El Paso, Texas and first joined NASA's astronaut corps in 1998, a full decade after submitting his first application.

"The reason I'm here is because I wanted to be part of space exploration," said Olivas, 41, told reporters in a preflight interview. "I'm looking forward to it. It's been a long journey, but it's been a very satisfying one."

That journey began as a child, when Olivas would scan the skies from the roof of his home alongside his father, who used to build rocket engine components during work as a machinist, the astronaut said.

"It'll be, for me, very full circle-ish to go from being a kid on top of a roof in El Paso, Texas to being literally on top of the world working on a tremendous feat of human engineering and scientific progress," Olivas said, adding that he hopes for a chance to look out away from Earth during his spacewalks. "And then to look deep into space knowing that that view into the past is really our future, that's what I'm looking forward to the most."

Olivas holds both bachelors and masters degrees in mechanical engineering, and ultimately earned a Ph.D. in mechanical engineering and materials science from Rice University. The married father of five holds six U.S. patents and – among other professions – helped evaluate materials for future spacesuits before joining NASA's Jet Propulsion Laboratory (JPL) as a senior research engineer.

In 1998, Olivas joined NASA's spaceflyer ranks and first served within the agency's Robotics Branch as the lead for the space station's robotic arm and planned Dextre robot attachment. He also helped develop tools and techniques for in-flight shuttle heat shield repairs before heading an ISS Branch team that watches over the proper configuration and assembly of station modules and cargo ships.

"I still look up today and I realize how much there is out there that we don't know," Olivas said. "I'm very proud and very happy to be working in this industry where we're taking baby steps, but at least we're moving in the right direction."

Explorer at heart

Like Olivas, Swanson joined NASA's astronaut ranks in 1998 as much to push his own personal boundaries as those of human spaceflight.

"I've always wanted to do a kind of exploring," said Swanson, 46, in a NASA interview. "[I]f I could have lived 200 years ago, I would have loved to have been with like Lewis and Clark, and just been living in the woods and exploring all sorts of new areas...But since I couldn't do that, I figured the next best thing was to try to be an astronaut. And I got lucky."

But Swanson did not wait to become an astronaut before joining NASA. He first signed on to the space agency in 1987 as a systems engineer in the Aircraft Operations Division at the Johnson Space Center (JSC) in Houston, Texas where NASA trains its astronaut corps. He earned a doctorate in computer science from Texas A&M University among other degrees.

Swanson hails from Steamboat Springs, Colorado, where he began an active lifestyle of camping and hiking. Those interests later gave way to outdoor sports, weight lifting, running, woodworking and spending time with his wife Mary and their three children.

"The way I kind of look at it, this spaceship is kind of like a camping trip," Swanson said. "It's a small volume that you live in without the comforts of home."

It was at JSC that Swanson worked with NASA's Shuttle Training Aircraft, a modified aircraft designed to simulate the flight characteristics of an actual orbiter during landing. That experience will come in handy on STS-117, where Swanson will serve as both spacewalker and flight engineer to assist Atlantis' commander and pilot during liftoff and landing.

Completing construction of the space station, and applying lessons learned there to future treks to the Moon or beyond, is vital for humanity's constant push to explore, said Swanson, who added that he is grateful to play a part in the orbital laboratory's evolution.

"I've been working at NASA for quite a few years and so it's just...wonderful to kind of see this whole thing come to fruition, the whole space station itself," said Swanson. "It's just a dream come true."

• SPACE.com Video Interplayer: Space Station Power Up with STS-117
• STS-117 Power Play: Atlantis Shuttle Crew to Deliver ISS Solar Wings
• Complete Shuttle Mission Coverage