spectroscopy - Can stars be observed from space by x-rays, near infrared and radio wavelengths?

Yes, and not only from space but from the Earth surface too. Stars emit in almost all wavelengths depending on their surface temperatures. The hotter the star is the shorter (higher energy) wavelengths it'll emit.

You can try this simulator to check this:

http://astro.unl.edu/naap/blackbody/animations/blackbody.html