NASA: Last Space Shuttle Mission Will Launch July 8

This story was updated at 4:51 p.m. EDT.

It's official: NASA's last space shuttle launch in history is set to blast off from Florida on July 8.

Senior agency officials made the decision today (June 28) after an extensive review of the space shuttle Atlantis, which will fly the upcoming mission to the International Space Station, as well as the shuttle's four-astronaut crew and ground teams.  

Atlantis is slated to liftoff from its seaside Launch Pad 39A at the Kennedy Space Center in Florida on July 8 at 11:26 a.m. EDT (1526 GMT). [Gallery: Shuttle Atlantis' Last Launch Pad Trek]

NASA is retiring its three space shuttles this year to make way for a new space exploration program aimed at sending astronauts to asteroids and other deep space targets. The shuttles Discovery and Endeavour have already flown their final missions.

Atlantis' 12-day mission will deliver vital spare parts to the space station to help keep the orbiting lab going after the shuttle era ends. It will be NASA's 135th shuttle mission since the program began 30 years ago.

"We're really looking forward to achieving this mission, putting the station where it needs to be and finishing strong with STS-135," Mike Moses, chair of the shuttle's mission management team, said in a news briefing this afternoon.

During today's meeting, top NASA shuttle officials reviewed outstanding issues from the agency's previous spaceflight — the shuttle Endeavour's STS-134 mission — to make sure they won't impact Atlantis' flight.

"We had a very thorough review," said Bill Gersteinmaier, NASA's space operations chief. "We spent quite a bit of time going over each activity going on on this flight. This flight is incredibly important to the space station. The cargo coming up on this flight is really mandatory. The teams did a tremendous job today of staying on point, getting ready for the mission, and getting ready for the launch."

They also checked on repairs to a main engine fuel valve on Atlantis that leaked during a recent fueling test on June 15. The leaky valve was replaced and technicians at the launch pad completed a successful test on the new valve, NASA officials said.

Officials also checked modifications to Atlantis' external fuel tank, reinforcements designed to prevent the type of cracks found on the shuttle Discovery's tank before its own final launch earlier this year. Discovery's liftoff was delayed months due to the cracks, but eventually launched flawlessly on Feb. 24.

The results of Atlantis' fueling test earlier this month showed no cracks or other anomalies, agency officials said.

Atlantis' final astronaut crew, which includes commander Chris Ferguson, pilot Doug Hurley and mission specialists Sandra Magnus and Rex Walheim, will arrive at Kennedy Space Center on July 4 at 2:45 p.m. EDT (1845 GMT).

With the shuttle program's impending end in sight, NASA officials also highlighted their admiration for the ground teams' hard work to round out the program on a high note.

"That professionalism and their dedication to the program over many, many years comes an internal commitment to do the job right," said shuttle launch director Mike Leinbach. "I know they're going to do their job as perfectly as they have in the past. Yes, they know the end is coming. We've known this is coming for a long time, but nevertheless, the end of the program - something a lot of these folks have been with for 30 years - the mood is getting more and more somber. The end is just weeks away instead of years away. It's getting more somber."

You can follow SPACE.com Staff Writer Denise Chow on Twitter @denisechow. Visit SPACE.com for complete coverage of Atlantis's final mission STS-135 or follow us @Spacedotcom and on Facebook.