Ranger 3

NSSDC ID: 1962-001A

Description:
Ranger 3 was designed to transmit pictures of the lunar surface to
Earth stations during a period of 10 minutes of flight prior to
impacting on the Moon, to rough-land a seismometer capsule on
the Moon, to collect gamma-ray data in flight, to study radar
reflectivity of the lunar surface, and to continue testing of the
Ranger program for development of lunar and interplanetary space-
craft. Due to a series of malfunctions the spacecraft missed the
Moon. 

Ranger 3 was the first of the so-called Block II Ranger designs. The
basic vehicle was 3.1 m high and consisted of a lunar capsule
covered with a balsawood impact-limiter, 65 cm in diameter, a
mono-propellant mid-course motor, a 5080-pound thrust retro-
rocket, and a gold- and chrome-plated hexagonal base 1.5 m in
diameter. A large high-gain dish antenna was attached to the base.
Two wing-like solar panels (5.2 m across) were attached to the
base and deployed early in the flight. Power was generated by
8680 solar cells contained in the solar panels which charged a
11.5 kg 1000 W-hour capacity AgZn launching and backup battery.
Spacecraft control was provided by a solid-state computer and
sequencer and an earth-controlled command system. Attitude
control was provided by Sun and Earth sensors, gyroscopes,
and pitch and roll jets. The telemetry system aboard the space-
craft consisted of two 960 MHz transmitters, one at 3 W power
output and the other at 50 mW power output, the high-gain
antenna, and an omni-directional antenna. White paint, gold and
chrome plating, and a silvered plastic sheet encasing the retro-
rocket furnished thermal control.