KSP_win_0_13_1.zip

Here is the official site

Kerbal Space Program is a game where the player creates and manages his own space program.
Build spacecraft, fly them, and try to help the Kerbals to fulfill their ultimate mission of conquering space.

The game is currently under heavy development. This means the game will be improved on a regular basis, so be sure to check back for new updates.
Right now, KSP is in Alpha state, but we want you to try it out and have fun with it. The first versions are free to download and play, and will remain so forever.

The KSP Team is strongly commited to the project, and we are always listening for feedback from the players.

This torrent aims to help the main download server, as the main server is having problems keeping up.