MO's orbit is highly eliptical at the moment, looking somewhat like an egg. That will change over time but let's use this for the moment. The "fat" part of the egg (orbit) will be near periapis. The vehicle's altitude will be decreasing rapidly but the rate of decrease slows as it approaches periapis. Of course, the vehicle is also travelling at its highest velocity at that point. As MO's altitude will approach periapsis over a period of several minutes, the drag will be increasing. Peak aerodynamic pressure, Max Q, will happen at periapis and then the pressure (drag) will decline over several minutes. The entire drag pass might last upwards of 20 minutes from the time drag is detectable through peak and back out of the atmosphere. The peak drag itself might only last for a couple minutes and will be somewhere around 2.2 Newtons, using the area from MCO and the atmospheric density figures from MGS as a guideline. Still, the average drag for that pass will be somewhere on the order of 1 Newton. Think of it this way, if you were going to fire a thruster for the same amount of time as the drag pass, you wouldn't want to generate a lot of thrust because a burn of that duration might reduce the orbit too quickly.