Which design is easier to maintain and keep aligned?

• A. Refracting
• B. Reflecting
• C. Radio
• D. Space-based

Answer: (A)

Understanding how easy it is to keep an optical system aligned comes down to how the light path is arranged. A refracting telescope uses fixed lenses inside a rigid tube, so once the lenses are properly mounted, there are few parts that can drift and little need for realignment. In contrast, a reflecting telescope relies on mirrors that must stay precisely positioned; small shifts from gravity, temperature changes, or handling can misalign the mirrors, so keeping the image sharp means regular collimation. Space-based designs are extremely hard to service, making any misalignment costly to fix, and radio telescopes involve large structures and receivers that require ongoing alignment as conditions change. So, the fixed-path design with lenses is the easiest to maintain and keep aligned.