[Ranger Spacecraft] [Ranger 7 image 199]

Ranger (1961 - 1965)

The Ranger series was the first U.S. attempt to obtain close-up images of the Lunar surface. The Ranger spacecraft were designed to fly straight down towards the Moon and send images back until the moment of impact. Shown above is the Ranger spacecraft and an image of the Moon taken by the Ranger 7 A series camera immediately before impact. This image has a resolution of .5 meters. Ranger 7 impacted in mare terrain modified by crater rays. Ranger 8 also impacted in mare terrain, but this area contained a complex system of ridges. Ranger 9 impacted in a large crater in the lunar highlands. Below is the first image of the Moon taken by Ranger 7, about 17 minutes before impact.

[Ranger 7 image 1]

Click on the spacecraft name for detailed information on the spacecraft and mission.

Ranger 7

Launched 28 July 1964
Impacted Moon 31 July 1964 at 13:25:49 UT
Latitude 10.70 S, Longitude 339.33 E - Mare Cognitum (Sea That Has Become Known)
Ranger 7 Experiments and Data
Ranger 7 images of the Moon

Ranger 8

Launched 17 February 1965
Impacted Moon 20 February 1965 at 09:57:37 UT
Latitude 2.71 N, Longitude 24.81 E - Mare Tranquillitatis (Sea of Tranquility)
Ranger 8 Experiments and Data
Ranger 8 images of the Moon

Ranger 9

Launched 21 March 1965
Impacted Moon 24 March 1965 at 14:08:20 UT
Latitude 12.91 S, Longitude 357.62 E - Alphonsus crater
Ranger 9 Experiments and Data
Ranger 9 images of the Moon

Each Ranger spacecraft had 6 cameras on board. The cameras were fundamentally the same with differences in exposure times, fields of view, lenses, and scan rates. The camera system was divided into two channels, P (partial) and F (full). Each channel was self-contained with separate power supplies, timers, and transmitters. The F-channel had 2 cameras: the wide-angle A-camera and the narrow angle B-camera. The P-channel had four cameras: P1 and P2 (narrow angle) and P3 and P4 (wide angle). The final F-channel image was taken between 2.5 and 5 sec before impact (altitude about 5 km) and the last P-channel image 0.2 to 0.4 sec before impact (altitude about 600 m). The images provided better resolution than was available from Earth based views by a factor of 1000. These highly detailed images showed Apollo planners that finding a smooth landing site was not going to be easy.

[Final Ranger 7 pictures] Images taken by Ranger 7 one second before impact

[Red bullet] More information on Ranger missions and cameras
[Red bullet] Lunar images from Ranger and other missions

The earlier Rangers, 1 through 6, all failed for various reasons. Information on these missions is given below:

Ranger 1
Launched 23 August 1961
Failed to leave Earth parking orbit

Ranger 2
Launched 18 November 1961
Failed to leave Earth parking orbit

Ranger 3
Launched 26 January 1962
Earth contact lost, missed the Moon by ~36,800 km

Ranger 4
Launched 23 April 1962
Sequencer failed, impacted the Moon 26 April 1962

Ranger 5
Launched 18 October 1962
Earth contact lost, missed the Moon by 725 km

Ranger 6
Launched 30 January 1964
Cameras failed, impacted the Moon 2 February 1964

 Images of the Moon - Ranger and Other Spacecraft

 Lunar Impact: A History of Project Ranger  (NASA SP-4210, 1977)
[Blue bullet] Ranger information at the Lunar and Planetary Institute

[Red bullet] Moon home page
[Red bullet] Lunar Exploration home page

Dr. David R. Williams, dave.williams@nasa.gov
NSSDCA, Mail Code 690.1
NASA Goddard Space Flight Center
Greenbelt, MD 20771

NASA Official: Dave Williams, david.r.williams@nasa.gov
Last Updated: 22 September 2005, DRW