168 miles is on the low side of LEO. Earth’s orbital velocity is ~28 km/h. In order to stay in orbit, an object would have to maintain that orbital velocity AND stay above 160 miles. This object’s orbit is decaying rapidly. Objects under 100 miles in altitude will be exposed to denser atmosphere and will fall back to Earth in relatively short order.
I looked up the space shuttle last night and one article mentioned that the average mission altitude was only in the 170s. ISS is higher at 260 or so.