The space shuttle Discovery is set to make its final blast off into orbit on Thursday night.
Discovery blasted off on its first mission in 1984 and is now the oldest space shuttle in service. It's played a really important role in how much we know about space.
The shuttle was named after Captain Cook's famous ship which he used to explore unseen lands in the 1790s.
It carried the Hubble Telescope into orbit in 1990, which has allowed scientists to explore and learn about other galaxies.
So far the shuttle has spent over 352 days in space and has completed more missions than any other spacecraft.
It has taken 180 astronauts to the International Space Station and travelled a whopping 140 million miles!
From now on American astronauts will have to travel to the International Space Station on Russian Soyuz Rockets until they can build a new fleet.
Experts at Nasa hope that they can develop new rockets which will be able to take astronauts deeper into our solar system.