The Altius mission takes 2D spectral images of the atmosphere’s bright limb, covering field of 100 km x 100 km projected at Earth’s tangent point. The Altius instrument is designed to be able to operate continuously over one orbit in various modes. It will perform acquisitions in a broad wavelength range coping with large differences in light intensity across the various observed scenes. The satellite will follow a Sun-synchronous orbit at an altitude baseline of 690 km and at a local time of 10:00. Additionally, it will take advantage of the satellite platform’s agility to operate at different attitudes. This allows for different observation modes, achieving global coverage in three days or less, with a resolution of 5 degrees in latitude and 10 degrees in longitude, which is a threshold requirement for the accuracy of present chemical assimilation models.