help with pattern for puff ripple afghan

Hi everyone. I am trying to make a ripple afghan with puff stitches, but there are some lines in the pattern that I don't understand.
The pattern is Royal Ripple from a Red Heart Afghans book.
Row 4 is where the puffs are made
At row 5 is says to
"Work 2 sc in first dc, sc in next dc, * (sc in next ch-1 sp, sc in top of puff st) 4 times, sc in next ch-1 sp, sk 2 puff sts (sc in next ch-1 sp, sc in top of puff st) 4 times, sc in next ch-1, 5 sc in top of puff st, rep from * across, ending with sc in last ch-1 sp, sc in last dc, 2 sc in top of ch-3, ch 1, turn

I don't understand what "1 sp" means in this sentence?
sc in next ch-1 sp

thanks for your help!

Forums: 

It isn't 1-space, it is ch-1 space. On your previous row or round, you were told to work a chain in between some stitches. This created a space and because the space was created by a single space, it is a ch-1 space. Sometimes you will create a ch-2 space, or a ch-3 space or a ch-x space where x represents the number of chains you had worked in between other stitches.

thanks! It was driving me crazy. :-)