The Starmade-Starter is the launcher for downloading game files.
The Starmade application by itself can't be run without it.
You can find the download page for it here:
Once downloaded open up your web browser's downloads and extract the Starmade-Starter in the location you would like the game to download your game files to.
It's recommended you place it somewhere where administrator limitations do not take affect.
Stay away from placing it on your desktop and in Program Files folders.
You will need to login on first start and set an installation directory, after it downloaded and placed all files you are good to go.