Pioneer 0 consisted of a thin cylindrical midsection with a squat truncated cone frustrum on each side. The cylinder was 74 cm in diameter and the height from the top of one cone to the top of the opposite cone was 76 cm. Along the axis of the spacecraft and protruding from the end of the lower cone was an 11 kg solid propellant injection rocket and rocket case, which formed the main structural member of the spacecraft. Eight small low-thrust solid propellant velocity adjustment rockets were mounted on the end of the upper cone in a ring assembly which could be jettisoned after use. A magnetic dipole antenna also protruded from the top of the upper cone. The shell was composed of laminated plastic.
The scientific instrument package had a mass of 11.3 kg and consisted of an image scanning infrared television system to study the Moon's surface, a diaphragm/microphone assembly to detect micrometeorites, a magnetometer, and temperature-variable resistors to record spacecraft internal conditions. The spacecraft was powered by nickel-cadmium batteries for ignition of the rockets, silver cell batteries for the television system, and mercury batteries for the remaining circuits. Radio transmission was at on 108.06 MHz through an electric dipole antenna for telemetry and doppler information and a magnetic dipole antenna for the television system. Ground commands were received through the electric dipole antenna at 115 MHz. The spacecraft was to be spin stabilized at 1.8 rps, the spin direction approximately perpendicular to the geomagnetic meridian planes of the trajectory.
See also: Pioneer programSpacecraft design