MCO had an 11 square meter drag area
and that's about what I remembered reading somewhere for Mars Odyssey. In the info I provided earlier, they said MO will descend to about 120 kilometers where the peak dynamic pressure will be an average of roughly 0.2 N/square meters. If that's right, then the peak drag will be on the order of 2.2 Newtons. The average drag for an entire pass will be somewhat less, on the order of 1 Newton.