The Phantom Torso has become a regular sight on the International Space Station over the last four months but now the limbless mummy-like humanoid is back home again. Officially known as Matroshka, the Phantom Torso is not so much a robot as a humanoid-shaped scientific instrument. Matroshka's 35 layer high density plastic body is loaded with 416 lithium-crystal dosimeter sensors that collect data from galactic cosmic rays (GCRs) and other radiation sources in space that might endanger astronauts. The sensors are placed in the location of vital human organs. All the data collected is being used by NASA scientists to verify the accuracy of computer models used to predict the safety of space missions for human astronauts.