Space blood test: can you prick your finger in zero gravity?

This study tested whether healthy volunteers could collect their own blood using a simple finger-prick method during brief periods of weightlessness on parabolic flights. The goal was to see if this technique works in space-like conditions for measuring caffeine levels. Thirty participants tried to deposit a drop of blood onto special paper within 22 seconds of microgravity. The results will help develop better ways to monitor drug effects in astronauts.