Ranger 2

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Ranger 2
Organization NASA
Major contractors Jet Propulsion Laboratory
Mission type Lunar Science
Satellite of Earth
Orbits 32
Launch date November 18, 1961 at 08:09:00 UTC
Launch vehicle Atlas-Agena B
Mission duration 2 days
Decay November 20, 1961
NSSDC ID 1961-032A
Webpage NASA NSSDC Master Catalog
Mass 304 kg
Orbital elements
Semimajor axis 6,574.2 km
Eccentricity .?
Inclination 33.3°
Orbital period ~89 minutes
Apoapsis 242 km
Periapsis 150 km
Instruments
Lyman-Alpha Telescope to scan earth to study hydrogen constituent of exosphere
Magnetometer to measure magnetic field in interplanetary space

Ranger 2 was a flight test of the Ranger spacecraft system of the NASA Ranger program designed for future lunar and interplanetary missions. Ranger 2 was designed to test various systems for future exploration and to conduct scientific observations of cosmic rays, magnetic fields, radiation, dust particles, and a possible hydrogen gas "tail" trailing the Earth.

[edit] Spacecraft design

Ranger 2 was of the Ranger Block 1 design and was almost identical to Ranger 1. The spacecraft consisted of a hexagonal base 1.5 m across upon which was mounted a cone-shaped 4 m high tower of aluminum struts and braces. Two solar panel wings measuring 5.2 m from tip to tip extended from the base. A high-gain directional dish antenna was attached to the bottom of the base. Spacecraft experiments and other equipment were mounted on the base and tower. Instruments aboard the spacecraft included a Lyman-alpha telescope, a rubidium-vapor magnetometer, electrostatic analyzers, medium-energy-range particle detectors, two triple coincidence telescopes, a cosmic-ray integrating ionization chamber, cosmic dust detectors, and scintillation counters.

The communications system included the high gain antenna and an omni-directional medium gain antenna and two transmitters at approximately 960 MHz, one with 0.25 W power output and the other with 3 W power output. Power was to be furnished by 8680 solar cells on the two panels, a 53.5 kg silver-zinc battery, and smaller batteries on some of the experiments. Attitude control was provided by a solid state timing controller, Sun and Earth sensors, gyroscopes, and pitch and roll jets. The temperature was controlled passively by gold plating, white paint, and polished aluminum surfaces.

[edit] Mission

The spacecraft was launched into a low Earth parking orbit, but an inoperative roll gyro prevented Agena restart. The spacecraft could not be put into its planned deep space trajectory, resulting in Ranger 2 being stranded in low earth orbit upon separation from the Agena stage. The orbit decayed and the spacecraft reentered Earth's atmosphere on November 20, 1961.

[edit] External links