The TESSERACT (Transition Edge Sensors with Sub-EV Resolution And Cryogenic Targets) collaboration consists of individuals from

• Argonne National Laboratory
• Caltech
• Florida State University
• Lawrence Berkeley National Laboratory
• Texas A&M University
• University of California Berkeley
• University of Grenoble
• University of Lyon
• University of Massachusetts Amherst
• University of Michigan,
• University of Zurich

The project is designed to address Principal Research Direction 2 identified in this report: Detect individual galactic DM particles below the proton mass through interactions with advanced, ultra-sensitive detectors. The TESSERACT project planning phase, funded through the DOE Dark Matter New Initiatives program since June 2020, covers the transition from R&D to a project. This project planning phase aims to produce a fully defined experimental concept and project by the end of FY25 based on a DOE-provided funding profile. Note that this schedule projection has been extended by one year, given the reduced FY22 budget compared with the expectation from a year ago. TESSERACT is a single collaboration that will deliver the shielding, cryogenics, calibration tools, detectors, and project management necessary to perform two experiments: SPICE (Sub-eV Polar Interactions Cryogenic Experiment) and HeRALD (Helium Roton Apparatus for Light Dark Matter). Together, these experiments will be sensitive to both nuclear recoil interacting DM (NRDM) and electron recoil interacting DM (ERDM).