Yes - for a few minutes before you burn up!

300km is about the lowest practical orbit with any reasonable lifetime, it depends on the size of the satelite and the solar weather

You can improve things a little by flying in an elliptical orbit. Some of the KH8s have listed orbits with perigees as low as 125km -- but they're not that low for the whole orbit. They also didn't have particularly long mission durations (weeks, not years) and may have used their attached Agena stages for some reboosting. Still impressive, though!