In parallel to the preflight measurements of the cryostat's internal straylight sources a new study of the external straylight suppression by the baffle system was performed by BRO, Tucson and was monitored by ESA and the Straylight Working Group. A road map of the scans around Saturn is presented in Figure 7 . The result of these scans around Saturn is the extended beam profile shown in Figure 8 . There is excellent agreement with the theoretical predictions of the BRO analysis. In a similar way, measurements were made at other wavelengths with other detectors.
Numbers indicate measurement positions.
The scans were extended to large distances in order to determine the sky background and were performed in two directions in order to assess possible memory effects. The numbers refer to the road map shown in Figure 7. In September and October 1997, during its extended lifetime, ISO experienced several total solar eclipses of up to 140 min duration inside the science window. The Moon straylight was similarly determined. However, the satellite could not be commanded to change its pointing with respect to the Moon's position during the eclipses.