The Hubble Telescope will have to wait a bit more than expected for NASA's final visit, as, due to complications experienced during the construction of the shuttle's fuel tanks, the mission has been delayed for at least one month.

Although the project to repair the Hubble Space Telescope (HST) was scheduled for August, there is no chance for it to begin before the end of September. According to the plan, seven astronauts will be taken on site by the Atlantis space shuttle.

The mission's goal is to enable the telescope to properly function for five more years, as in 2013 a replacement should be ready to take over. The seven astronauts, all coming from the U.S., have already been training since February last year in order to prepare for the upcoming mission. They are to install a cosmic origins spectrograph and also replace a camera of the telescope, which has been working since 1993 with a Wide Field Camera 3.

Shuttle program manager John Shannon said that the team encountered some difficulties while attempting to incorporate "all the post-Columbia design changes" and that more time was needed in order to finalize everything. "It's a small price to pay to tell you the truth, four to five weeks, for all the improvements that we're getting on this tank," Shannon said on Thursday.

Although now only five shuttle flights will be performed instead of six until the end of the year, NASA officials are still very optimistic and hope that the space station will be completed in 2010.