My boy is painting outer space
In the first two stanzas, Paterson describes his son, Jamie, drawing the universe. The opening line is a striking beginning, as it suggests that Jamie has taken on a mammoth task, but also that in painting he is creating the universe; perhaps in the eyes of his father he has such power. The words "My boy" convey a sense of the poet's pride in his son for taking on such a challenge.
The next lines expand on the first by listing all that is included in this "space" and the connection between them.
and all the circuitry they run/ in one great heavenly design.
The use of "circuitry" suggests an electronic circuit made up of the planets that are connected in circular orbits; it also loops us back to the title. The enjambment also implies that this circle is completed by a "heavenly design", namely fate, introduced in stanza two. The line spilling into the next stanza could suggest the enormity of the universe and everything in it. It is as if it all cannot be contained. This could also be read as introducing a sense of imperfection that will continue through the poem.
The word "design" is connected to drawing and suggests that, like Jamie's picture, the whole of the universe is mapped out by some force or deity.
his hand shakes, and he screws it up
Just at the last minute, Jamie's drawing goes wrong. It doesn’t turn out as he planned. The word choice here implies he messed it up; the use of slang "screws it up" suits a young boy's frustration, but might also allude to the twisting, circular motion of balling the paper.