Ranger 1 was a spacecraft whose primary mission was to test the performance of those functions and parts necessary for carrying out subsequent lunar and planetary missions using essentially the same spacecraft design. A secondary objective was to study the nature of particles and fields in interplanetary space.

Spacecraft and Subsytems

Spacecraft and Subsystems

The spacecraft was of the Ranger Block 1 design and 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 solar X-ray scintillation counters.

The communications system included the high gain antenna and an omni-directional medium gain antenna and two transmitters, one at 960.1-mhz with 0.25 W power output and the other at 960.05-mhz with 3 W power output. Power was to be furnished by 8680 solar cells on the two panels, a 57 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, and pitch and roll jets. The temperature was controlled passively by gold plating, white paint, and polished aluminum surfaces.


Lyman-Alpha Telescope

The experiment was designed to scan the earth in the Lyman-Alpha region (1050 A to 1350 A) and to study the hydrogen constituent of the exosphere. The monitoring was done with a telescope that has a parabolic mirror with an ionization chamber located at its focus and a cylindrical radiation shield that protected the telescope from undesired scattered light. As the telescope mechanically scanned the regions, the detector produced an electrical signal proportional to the amount of the Lyman-Alpha radiation incident upon it, giving a crude picture somewhat similar to a TV image. The data were impossible to interpret, however, since the satellite did not leave the vicinity of the earth and the vehicle began tumbling.


A rubidium-vapor magnetometer, mounted in the center of a hollow spherical fiberglass shell 13 in. in diameter, was designed to measure the magnitude and direction of the magnetic field in interplanetary space and to detect occurances of temporal and spatial fluctuations. Bias coils were wound around the shell to send electric currents of known strengths during the measuring sequence. proper sequencing of currents in the coils allows determination of both the strength and direction of the magnetic field in space. The instrument took measurements of fast field fluctuations of up to 30 gammas per sec in order to study the fine structure of the field. The sensitivity range of the experiment was from 0.05 to 105 gammas, with an accuracy of .05 gamma. The measurements were to be made of the geomagnetic field from a distance of approximately 6 earth radii, The experiment transmitted data for the lifetime of the spacecraft (10 days), but a low earth orbit, rather than the intended deep space orbit, prevented accomplishment of the full mission objectives.

Electrostatic Analyzer

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Charged Particle (Iowa)

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Charged Particle (Chicago)

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Cosmic Ray

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Cosmic Dust

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Scintillation Counters

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Launch-Orbit Information

Launch Information

Launch Date: 1961-08-23 at 10:02:00 UTC
Launch Vehicle: Atlas-Agena B
Launch Site: Cape Canaveral, United States
Decay Date: 1961-08-30
Mass: 306.2 kg

Orbital Parameters

Central Body: Earth
Epoch start: 1961-08-23 10:02:00 UTC
Epoch stop: 1961-08-30 00:00:00 UTC

Periapsis: 179km Apoapsis:446km Period: 91.1 minutes Inclination: 32.9° Eccentricity: 0.01994

Mission Profile

The Ranger 1 spacecraft was designed to go into an Earth parking orbit and then into a 60,000 x 1,100,000 km Earth orbit to test systems and strategies for future lunar missions. Ranger 1 was launched into the Earth parking orbit as planned, but the Agena B failed to restart to put it into the higher trajectory, so when Ranger 1 separated from the Agena stage it went into a low Earth orbit and began tumbling. The satellite re-entered Earth's atmosphere on 30 August 1961. Ranger 1 was partially successful, much of the primary objective of flight testing the equipment was accomplished but little scientific data was returned.

Total research, development, launch, and support costs for the Ranger series of spacecraft (Rangers 1 through 9) was approximately $170 million.