STAR-D Information

What happens to one of life’s most fundamental defense mechanisms when gravity disappears? STAR-D is an international, student-led space biology experiment built to answer that question in real microgravity. It investigates phagocytosis, the process cells use to engulf and break down foreign particles, using Dictyostelium discoideum, a safe model organism sharing key mechanisms with mammalian immune cells. At the onset of microgravity, a fully autonomous lab-on-chip will inject fluorescent bacterial particles and record the cellular response in real time through onboard bright-field and fluorescence microscopy. After recovery, flight data will be compared with identical ground controls to measure changes in particle uptake, phagosome maturation, and cell morphology. Selected for ESA sponsorship within the Swedish-German REXUS/BEXUS programme, STAR-D is scheduled to launch aboard REXUS 38 from Esrange Space Center, Sweden, in March 2027. It is the second French-led experiment ever selected for a REXUS rocket, and France’s first in nearly a decade. By turning a sounding rocket into a miniature biological laboratory, STAR-D is helping shape a new generation of compact, autonomous research platforms for studying cellular behavior beyond Earth, and building knowledge for the future of human spaceflight.