Cut out and score the TIRS instrument, H. Score
along the sides and form a box but don’t glue that
yet. The large Earth shade needs to be scored on the
back side in two places and folded forward first. Glue
those triangular shapes on top of each other.
The narrow section opposite the large Earth shield
folds back and forms an extension at the corner of
main unit for the Earth shield hinge. That’s what you
glue together to form the main TIRS unit box.