Question

If all else stays the same, which change could be made to cause an increase in the gravitational force on a space shuttle?

increasing the distance of the space shuttle from Earth
decreasing the distance of the space shuttle from Earth
increasing the universal gravitational constant acting on the space shuttle
decreasing the universal gravitational constant acting on the space shuttle

Answer 1

Decreasing the distance of the space shuttle from Earth.

By Newton's law of gravitation F = G M m / r^2, reducing r (distance) increases F. (G is a fixed constant and cannot realistically be changed.)