The Multi Ion Reflection Apparatus for Collinear Laser Spectroscopy (MIRACLS) at ISOLDE aims to measure nuclear ground-state properties such as the size, shape and electromagnetic moments of rare radioactive isotopes. These properties are extracted from the measurements of the isotopes’ hyperfine structure using laser spectroscopy. MIRACLS’ goal is to increase the sensitivity of conventional, fluorescence-based collinear laser spectroscopy by confining the investigated ions in an ion trap. This novel scheme allows for the ions to be probed up to several thousands of times.