PHOENIX: a Probe-Class Mission for Cosmology

Spectral distortions in the cosmic microwave background open a new window to the structure, content, and evolution of the universe. Detecting the expected signals at the few part-per-billion level requires background-limited sensitivity with careful control of instrumental signatures. PHOENIX is a Probe-class mission to map the CMB and diffuse astrophysical foregrounds at microwave through far-IR wavelengths. I describe the scientific goals and instrument design for the PHOENIX mission and use detailed time-ordered simulations to evaluate the projected instrument performance.