[5] Project Vanguard was a program managed by the United States Naval Research Laboratory (NRL), and designed and built by the Glenn L. Martin Company (now Lockheed Martin), which intended to launch the first artificial satellite into Earth orbit using a Vanguard rocket.

The lower three-fourths of the sphere was silicon monoxide-coated magnesium and the upper fourth and the conical extension were made of fiberglass (glass fiber phenolic resin).

[2] Power was provided by specially built Yardley Silvercels (AgZn chemical batteries) with non-magnetic lugs, designed to last approximately 3 months.

In its top center, the can also contained a smaller cylinder, which held the electronics for the X-ray, peak memory, temperature measurements, micrometeorite detector, and data encoder, above which was the 30 mW, 108.00 MHz Minitrack beacon transmitter.

All experiments functioned normally and the batteries lasted for 84 days, until 11 December 1959, at which time all communication with the spacecraft ceased.

The detectors were two identical ionization chambers sensitive to X-ray wavelengths produced in solar flares (2 to 8 Å, or 200 to 800 pm).

The instrumentation were designed to measure the 2 to 8 Å (200 to 800 pm) X-ray flux and record the peak solar flare intensity by means of a peak-reading memory device, during the daylight portion of each orbit.

[9] However, due to the overwhelming background radiation of the Van Allen Belts, its sensors were saturated, and no useful information on solar X-rays was gathered.

A puncture in the walls of either zone was detected by a differential pressure gauge mounted between them, and telemetered as a change in the length of one of the telemetry channels.

The microphone output was amplified, shaped, and fed into a magnetic counter unit, which provided continuously, in three-decimal digits, the cumulative count of impacts.

[11] Because of its symmetrical shape, Vanguard 3 was selected by the experimenters for use in determining upper atmospheric densities as a function of altitude, latitude, season, and solar activity.

By measuring the rate and timing of orbital shifts, the relevant atmosphere's parameters could be back-calculated knowing the body's drag properties.

Initial Naval Research Laboratory proposals for Project Vanguard included conical satellite bodies; this eliminated the need for a separate fairing and ejection mechanisms, and their associated weight and failure modes.

[13] After the scientific mission ended with data transmission ceasing on 11 December 1959, after 84 days of operation, Vanguard 3 and two pieces of the upper stage of the rocket used to launch the satellite became derelict objects.