The U.S. space agency NASA has announced it is going to try to launch the space shuttle Atlantis Friday.
The launch is scheduled for late Friday morning local time at Cape Canaveral, Florida.
Failure to launch the shuttle this week could delay the mission until October.
The Atlantis launch has already been postponed several times, both because of poor weather and for technical reasons.
Astronauts on the mission are expected to attach a 17-ton addition to the International Space Station. It will include a new set of giant solar energy panels that will reach 80 meters in length when fully unfurled.
Construction on the space station stopped after the shuttle Columbia disaster in February 2003 forced a long moratorium on shuttle flights.
Some information for this report provided by AP and AFP.