The NASA Twins Study was a major effort in the area of “omics” investigations: genomics, proteomics, epigenomics, transcriptomics. These have to do with the processes by which DNA is transcribed to proteins in the body, and the changes in this process that can occur as a consequence of the multiple stressors of spaceflight. This type of work draws on ongoing research in astrobiology, transcriptomics, and epigenetics. JHU investigators have played a major role in these areas, including involvement in the Twins Study.