ESA Science & Technology - FIRI Pointing Range

FIRI (the Far InfraRed Interferometer) is to have the capability to point in any direction within a maximum angle with respect to the anti-Sun direction. The maximum angle is to be at least ~25° out of the ecliptic, but the goal is to observe up to ~45° out of the ecliptic.

Two cones for both maximum angles around the anti-Sun direction are depicted here, with the spacecraft pointing 45° out of the ecliptic in this illustration.

For cosmology surveys imaging needs to be done in the north or south ecliptic pole directions, to avoid disturbance from the zodiacal light. However, for star and planetary system formation the need for observing out of the ecliptic is of less importance.