Astronauts can use 3D and molecular printers for shelter construction and food preparation on site instead of having to carry the materials to mission sites, thus A. lowering the long-run average cost of exploring the solar system, but increasing labor costs. B. lowering the long-run average cost of exploring the solar system, but increasing material costs. C. increasing the number of required rocket missions and thereby reducing the long-run average cost of exploring the solar system D. reducing the number of required rocket missions and thereby reducing the long-run average cost of exploring the solar system.

D. reducing the number of required rocket missions and thereby reducing the long-run average cost of exploring the solar system.

Explanation:

As you can see in the question above, the use of a 3D printer by astronauts can reduce the number of rocket emissions to transport equipment, parts for the repair of stations, food, construction of space bases, among others. This would be a great economic advantage for the laboratories, because it would allow reducing the number of rocket missions (which are extremely expensive) needed and thus reducing the average long-term cost of exploring the solar system.

A 3D printer is capable of printing a large number of parts and equipment at once, with an exact amount of raw material for that. This reduces material costs, in addition to avoiding waste of raw material.