The spacecraft did not reach the Moon as planned due to an incorrectly set valve in the upper stage which caused an accelerometer to give faulty information leading to a slight error in burnout velocity (the Thor second stage shut down 10 seconds early) and angle (3.5 degrees). This resulted in a ballistic trajectory with a peak altitude of 113,800 km around 1300 local time. The real-time transmission was obtained for about 75% of the flight, but the percentage of data recorded for each experiment was variable. Except for the first hour of flight, the signal to noise ratio was good. The spacecraft ended transmission when it reentered the Earth's atmosphere after 43 hours of flight on October 13, 1958 at 03:46 UT over the South Pacific Ocean. A small quantity of useful scientific information was returned, showing the radiation surrounding Earth was in the form of bands and measuring the extent of the bands, mapping the total ionizing flux, making the first observations of hydromagnetic oscillations of the magnetic field, and taking the first measurements of the density of micrometeorites and the interplanetary magnetic field.