Seven NASA astronauts and the shuttle Atlantis returned safely to Earth June 22

after a successful mission to boost the power grid aboard the international space station (ISS).

After one delayed attempt, Atlantis touched down in the California desert for a

3:49 p.m. EDT

landing on a backup runway at Edwards Air Force Base.

Atlantis Commander Rick Sturckow and his STS-117 crewmates delivered a $367.3 million pair of trusses and new solar arrays to the space station’s starboard side and stowed away an older solar wing atop the outpost during their 14-day mission.

“You got to love that symmetrical space station,” pilot Lee Archambault said during the flight, which evened out the station’s previous off-kilter profile. (See photo page 1)

The astronauts also packed away an older solar array, aided in the recovery of critical Russian computer systems aboard the ISS, and swapped out one of the orbital laboratory’s three-person Expedition 15 crew. Their four spacewalks included the repair of a torn thermal blanket – using surgical staples – on Atlantis’ left aft engine pod.

Returning to Earth aboard Atlantis with Sturckow were shuttle pilot Lee Archambault and mission specialists Patrick Forrester, Steven Swanson, James Reilly

, Danny Olivas and Sunita Williams, a former Expedition 15 flight engineer.

The successful flight of Atlantis’ STS-117 crew primed the space station’s power grid to support the addition of NASA’s new connecting node Harmony and the European Space Agency’s Columbus laboratory, both of which are slated to launch later this year.

In addition to installing the new Starboard 3/Starboard 4 (S3/S4) trusses, STS-117 spacewalkers also furled the sole remaining solar array extending from the station’s mast-like Port 6 (P6) truss. Stowing that array brought P6 one step closer towards its eventual relocation to the station’s port-most end on a later shuttle flight, NASA said.

Michael Suffredini, NASA’s ISS program manager, said the mission also completed the delivery and activation of intricate joints to rotate the station’s wing-like starboard and port solar arrays. With the installation of the S3 segment, the Mobile Transporter railway that allows the station’s robotic arm to traverse the length of the orbital laboratory’s metallic backbone-like main truss

also is complete, he added.

“We do have a lot of assembly left,” Suffredini said, adding that many the tasks ahead have been performed before. “We [are] probably, from a risk perspective, over 60 percent past the point where I think we’ve got really new things to learn.”

NASA plans at least 12 more shuttle mission to the ISS to complete the orbital laboratory’s assembly, with two additional missions possible to deliver cargo, equipment and other logistics. One non-ISS bound shuttle flight, set to launch in September 2008, is planned to overhaul the Hubble Space Telescope.