ALTEA in the four USLab positions (see Table 1). Top left: Position P1 (in this site the rack was temporarily missing and the Y-directed detectors were facing the USLab hull); Top right: P2 on the overhead with the Z-directed detectors inserted in an empty drawer; Bottom left: P3 on the port side with the Y-directed detectors inserted in an empty drawer; Bottom right: P4 on the overhead. X, Y, Z: ISS coordinate system. Photo courtesy of NASA.