SPI science prospects

With the launch of ESA's INTEGRAL satellite in october 2002, a gamma-ray observatory will become available to the scientific community that combines imaging and spectroscopic capacities in the 20 keV to 10 MeV energy range. In this paper, we summarise the science prospects of the SPI spectrometer aboard INTEGRAL which provides unprecedented spectral resolution with good imaging capabilities and high sensitivity. Emphasise will be given to the key objectives of SPI which are the determination of the galactic positron origin, the study of galactic star formation and nucleosynthesis activity via the radioactive trace isotopes 26Al and 60Fe, and the study of nucleosynthesis in supernova explosions and the gamma-ray line emission from their remnants.