Miniature X-ray Optics for Meter-Class Focal Length Telescopes

X-ray optics in great observatories such as Chandra X-ray Observatory and XMM-Newton have revolutionized not only X-ray astronomy but also astronomy and astrophysics in general. They also left an impression to the community outside that X-ray optics are necessarily bulky, massive, and expensive. This perception may reflect some reality, given X-ray optics’ reliance on grazing incidence. Recent advancement in X-ray instrumentation, however, enables compact, lightweight X-ray optics, opening a new era of X-ray astronomy across multiple science disciplines. The BepiColombo mission, currently on the way to Mercury, is the first planetary science experiment with a focusing X-ray telescope, where glass micropore optics (i.e., microchannel plate optics) were used to enable 1 m focal length X-ray optics. Electroformed-nickel-replication (ENR)-based optics are particularly promising in enabling compact X-ray telescopes that can be tailored to specific scientific requirements in a small volume. Here we review ongoing efforts and advancement in development of Miniature X-ray Optics (MiXO) as well as their future applications. With the increasing interest in SmallSat/CubeSat-based scientific endeavors, MiXO is expected to enable a variety of science mission concepts in astrophysics, planetary science, and heliophysics.