It is well known that electron-density irregularities in the mid-latitude sporadic-£ are induced by atmospheric turbulence. We investigate a rocket trajectory dependence of the form of their one-dimensional spectrum which can be derived during rocket experiments. Two possible trajectories for two directions (north-south and west-east) of rocket flights are considered. It is assumed that a rocket intersects the irregular layer twice, during ascent and descent. It is shown that a systematic difference between the spectra measured during the upleg and downleg portions of trajectories is bound to be observed in the case of the southward direction. The difference is found in the range of large wave numbers, for the irregularities mainly generated through the interaction of plasma involved in turbulent motions of the atmospheric gas with the magnetic field. In the case of eastward direction of rocket trajectories, no difference can be odserved.