The launch of space shuttle Atlantis has been delayed by Nasa because of tropical storm Ernesto.
Atlantis was supposed to blast off on Tuesday, but was delayed with Ernesto getting closer. A lightning strike on Friday also caused a delay.
Now Atlantis could be taken from the launch pad and back to its hanger to protect it from the storm.
If the shuttle is moved it could delay the launch even longer, and may mean it can't go into space until October.
If Atlantis does take off it will take important parts to the International Space Station during an 11-day mission.
Space shuttle flights will end in 2010, so the ISS must be finished by then and there is lots of work on it still to do.
It is thought that another 16 shuttle missions will be needed to complete the space station.
This is only the third scheduled launch of a space shuttle since Columbia exploded when returning to earth in 2003.