Infrared Astronomy is a relatively new subject but it has already radically altered our ideas about astronomical sources. Recent progress in this subject is the result of improved detection techniques, particularly the use of detectors at liquid helium temperatures. Unfortunately, the terrestrial atmosphere greatly restricts Infrared astronomers by allowing them to detect radiation only in narrow transmission win- dows and by presenting a foreground emission which limits the faintness of observable sources. It is only from aircraft or balloon altitudes that we can begin to observe faint...