Space blood test: volunteers prick their fingers in zero g for caffeine science

This study tested whether healthy volunteers could collect their own blood drops using a simple finger-prick method during brief periods of weightlessness on parabolic flights. The goal was to see if this technique works in microgravity for measuring caffeine levels after drinking standard amounts of caffeine. Thirty participants took part, and the study focused on how well they could make a proper blood spot on special paper within 22 seconds of zero gravity. This research is a first step toward understanding how drugs work differently in space.