Ranger 1

Infobox_Spacecraft
Name = Ranger 1


Organization = NASA
Major_Contractors = Jet Propulsion Laboratory
Mission_Type = Lunar Science
Satellite_Of = Earth
Launch = August 23, 1961 at 19:12 UTC
Launch_Vehicle = Atlas-Agena B
Decay = August 30, 1961
Mission_Duration = 7 days
Mass = 306.2 kg
NSSDC_ID = 1961-021A
Webpage = [http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1961-021A NASA NSSDC Master Catalog]
Semimajor_Axis = 6,690.3 km
Eccentricity = .019939
Inclination = 32.9°
Orbital_Period = 91.1 minutes
Apoapsis = 446 km
Periapsis = 179 km
Orbits = 110

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

Spacecraft design

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.

Mission

The Ranger 1 spacecraft was designed to go into an Earth parking orbit and then into a 60,000 by 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 August 30, 1961. Ranger 1 was partially successful, much of the primary objective of flight testing the equipment was accomplished but little scientific data was returned.

External links

* [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19780007206_1978007206.pdf Lunar impact: A history of Project Ranger (PDF) 1977]