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Ranger 1, 2
Ranger 1, 2 -

Credit: NASA. 26,666 bytes. 274 x 338 pixels.

Class: Planetary. Type: Lunar. Nation: USA. Agency: NASA. Manufacturer: JPL.

The primary mission of the early Ranger flight models was to test the performance of those functions and parts that were necessary for carrying out later lunar (Ranger) and planetary (Mariner) missions using the same spacecraft bus. A secondary objective was to study the nature of particles and fields in interplanetary space.

The spacecraft consisted of a hexagonal base upon which were mounted the spacecraft experiments, two solar panels, and high-and low-gain antennas. Instruments aboard the spacecraft included a Lyman-alpha telescope, a rubidium-vapour magnetometer, electrostatic analysers, medium-energy-range particle detectors, two triple coincidence telescopes, a cosmic-ray integrating ionisation chamber, cosmic dust detectors, and scintillation counters. Two 960-mhz transmitters were aboard the spacecraft, one with 0.25 W power output and the other with 3 W power output.


Total Mass: 305 kg.

Ranger 1-2 Chronology

29 May 1961 Ranger booster erected. Program: Ranger. Launch Vehicle: SLV-3 Atlas / Agena B.

Atlas booster 111-D, to be used for Ranger I, was erected on the launch pad at Cape Canaveral.

12 July 1961 First large space simulator in the United States Program: Ranger.

Jet Propulsion Laboratory announced that construction was under way on the first large space simulator in the United States capable of testing full-scale spacecraft of the Ranger and Mariner classes. Three primary space effects could be simulated: solar radiation, cold space heat sink, and a high vacuum equivalent to about one part in a billion of the atmospheric pressure at sea level.

23 August 1961 Ranger 1 Program: Ranger. Launch Site: Cape Canaveral . Launch Vehicle: Atlas LV-3A / Agena B. FAILURE: Agena B second stage failure. Mass: 306 kg. Perigee: 179 km. Apogee: 446 km. Inclination: 32.9 deg.

Lunar probe; failed to leave Earth orbit. Ranger 1, a test version of the spacecraft which would attempt an unmanned crash landing on the moon, was launched from the Atlantic Missile Range by an Atlas-Agena B booster. The 306 kg spacecraft did not attain the scheduled extremely elongated orbit because of the misfiring of the Agena B rocket. Although the spacecraft systems were tested successfully, only part of the eight project experiments could be carried out. Ranger 1 reentered on August 29 after 111 orbits. Ranger 1's primary mission was to test the performance of those functions and parts that are necessary for carrying out subsequent lunar and planetary missions using essentially the same spacecraft design.

18 November 1961 Ranger 2 Program: Ranger. Launch Site: Cape Canaveral . Launch Vehicle: Atlas LV-3A / Agena B. FAILURE: Agena B Second Stage failed to restart. Mass: 304 kg. Perigee: 150 km. Apogee: 242 km. Inclination: 33.3 deg.

Ranger ARanger A - Ranger A in assembly at JPL, Pasadena

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This was a flight test of the Ranger spacecraft system designed for future lunar and interplanetary missions. The spacecraft was launched into a low earth parking orbit, but an inoperative roll gyro prevented Agena restart resulting in Ranger 2 being stranded in low earth orbit. The orbit decayed and the spacecraft reentered Earth's atmosphere on 20 November 1961.


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Last update 12 March 2001.
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© Mark Wade, 2001 .