The thermal tiles on the space shuttle
Some minor damage has been spotted on the bottom of space shuttle Atlantis, after it blasted off on Monday.
The shuttle is on an 11-day mission to fix the Hubble telescope, which has been in orbit for 20 years.
Nasa engineers don't seem too worried about the damage, which is a series of chips about 50cm long on the right hand side of the shuttle.
The mission is considered dangerous by space experts as it is a long way from the International Space Station.
Nasa thinks this is when the damage may have happened
That means if something goes wrong, the astronauts can't go to the space station for help.
Nasa have got another shuttle - the Endeavour - prepared to go into space to rescue the crew if required.
Hubble has helped teach us about the way the Universe works, showing far-off stars and fantastic sights.
If everything goes to plan, the updated telescope will be 90 times more powerful than it originally was and should last until at least 2014.
Hubble Space Telescope
Launched 600km above the Earth in 1990
15.9m long; 4.2m wide; weighs 11,110kg
Made more than 93,000 trips around our planet
Looked at more than 24,000 things in space