The satellites and third stage tumbled into the Atlantic Ocean several hundred kilometers off the coast after about 500 seconds of flight.

The first stage of the three-stage Vanguard Test Vehicle was powered by a General Electric X-405 125,000 N (28,000 lbf) thrust liquid rocket engine, propelled by 7,200 kg (15,900 lb) of kerosene (RP-1) and liquid oxygen, with helium pressurant.

[1] The second stage was a 5.8 m (19 ft) high, 0.8 m (2 ft 7 in) of diameter Aerojet General AJ-10 liquid engine burning 1,520 kg (3,350 lb) Unsymmetrical dimethylhydrazine (UDMH) and White Inhibited Fuming Nitric Acid (WIFNA) with a helium pressurant tank.

The lower compartment held the batteries, and the upper compartment held the magnetometer electronics, an 80 milliwatt telemetry transmitter operating at 108.3 MHz, a 10 milliwatt Minitrack beacon transmitter at 108.00 MHz, and a command receiver.

[1] The Sub-Satellite (Sphere B) objective was to provide data on air density in the outer limits of the atmosphere of Earth.

On separation of the Magnetic Field Satellite, a preset latch would release the gas into the Sub-Satellite, inflating it and pushing it free of the spent third stage.

It contained no instrumentation and was designed to be optically tracked from Earth to provide data on the density of the upper atmosphere by measuring its effect on the satellite orbit.

Pressure from the engine exhaust pushed the thrust chamber to the limit of the gimbal stops, breaking them and causing loss of attitude control in flight.