Answer: Decreasing the distance of the space shuttle from Earth .
Explanation:
According to expression of gravitational force:

G = gravitational constant
= masses of two objects
r = Distance between the two objects.
F = Gravitational force
From the above expression we can say that gravitational force is inversely proportional to squared of the distance between the two masses.

So, in order to increase the gravitational force on space shuttle distance between the space space shuttle must be decreased.
Hence, the correct answer 'decreasing the distance of the space shuttle from Earth '.
Displacement depends upon the path taken as it is a vector.
From your problem above we would have a total displacement of;
Defining +x direction as east and -x direction as west
6east-3west+1east+6east-7west
6-3+1+6-7=3 blocks east or + x-direction
So even though they walked a total of 17 blocks it ends up only being 3 blocks total in +xdirection that was travelled by displacement.
Any questions please ask.
Answer:
This can be the FBD of the bag.
(my bag looks more like a box tho ^^")