Miniature, cold-cycle dilution refrigerators (DRs) are being explored as an alternative to adiabatic demagnetization refrigerators for the cooling of sensors aboard astrophysics balloon missions. In this talk, the design, function, and testing of a miniature, cold-cycle DR manufactured by Chase Cryogenics will be discussed. I will also briefly discuss our research on pulse tube refrigerators, which is part of an effort at NIST to minimize the size and infrastructure requirements of cryostats.