The Spitzer Space Telescope is one of them. Operated for 16 years before budgetary restraints shut it down, it still orbits the Sun on an Earth-trailing path that lets it slowly drift away from our home planet. Designed to see in the infrared, it observed the Universe from nearby asteroids to galaxies at the edge of the observable Universe billion so of light years away.
It also saw many Giant Molecular Clouds. While these are black to our eyes, they re warm enough (though still very chilly) that they glow in the infrared. And when Spitzer saw them, it
really saw them: