The SpaceX Dragon has been promoted, carrying its first live mammals next mission. The Dragon will be carrying 40 mousetronauts for a three-week stay in space. This is an important step to certifying the Dragon for crewed flights.
The Dragon just returned with a hold full of scientific samples, but it's already time to start planning the next mission. For its fourth supply run to the International Space Station, the space freighter will be carrying four rodent habitat modules. Each habitat is roomy enough for a complement of 10 mice or 6 rats. The rats can scamper around the habitat by grasping on grids lining the enclosure.