Scientists evaluating blood stem cells (IMAGE) University of California - San Diego Caption UC San Diego scientists will evaluate astronauts’ blood stem cells before, during and after spaceflight. Credit UC San Diego Health Sciences Usage Restrictions Use photo credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.