Complex sentence: Its opportunities will be limited because its instruments need to be pointed away from the Sun at all times to avoid damage, but the spacecraft has already taken a few of a planned series of images of the outer regions of the vulcanoid zone.
Split into simpler sentences: Its opportunities will be limited because its instruments need to be pointed away from the Sun at all times to avoid damage. The spacecraft has already taken a few of a planned series of images of the outer regions of the vulcanoid zone.