Both are NP4, Summer Kama is ungrailed while Space Ishtar is.
From the looks of it Summer kama is slightly better in damage on wave 3, refund, as well as having a shorter NP animation. However the differences are minuscule and they basically function the exact same as arts loopers.
0:00 Summer Kama
1:59 Space Ishtar
4:10 Side by Side
