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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Ranger program | 2/2 | https://en.wikipedia.org/wiki/Ranger_program | reference | science, encyclopedia | 2026-05-05T13:14:24.114675+00:00 | kb-cron |
=== Block 3 missions === Ranger 6, launched 30 January 1964, lunar probe, Moon impact, cameras failed Ranger 7 Launched 28 July 1964 Impacted Moon 31 July 1964 at 13:25:49 UT 10.35°S 20.58°W / -10.35; -20.58 (Ranger 7) - Mare Cognitum Ranger 8 Launched 17 February 1965 Impacted Moon 20 February 1965 at 09:57:37 UT 2.67°N 24.65°E / 2.67; 24.65 (Ranger 8) - Mare Tranquillitatis (Sea of Tranquility) Ranger 9 Launched 21 March 1965 Impacted Moon 24 March 1965 at 14:08:20 UT 12.83°S 2.37°W / -12.83; -2.37 (Ranger 9) - Alphonsus crater Ranger's Block 3 embodied four launches in 1964-65. These spacecraft boasted a television instrument designed to observe the lunar surface during the approach; as the spacecraft neared the Moon, it would reveal detail smaller than the best Earth telescopes could show, and finally dishpan-sized craters. The first of the new series, Ranger 6, had a flawless flight, except that the television system was disabled by an in-flight accident and could take no pictures. The next three Rangers, with a redesigned television, were completely successful. Ranger 7 photographed its way down to target in a lunar plain, soon named Mare Cognitum, south of the crater Copernicus. It sent more than 4,300 pictures from six cameras to waiting scientists and engineers. The new images revealed that craters caused by impact were the dominant features of the Moon's surface, even in the seemingly smooth and empty plains. Great craters were marked by small ones, and the small with tiny impact pockmarks, as far down in size as could be discerned—about 50 centimeters (20 inches). The light-colored streaks radiating from Copernicus and a few other large craters turned out to be chains and nets of small craters and debris blasted out in the primary impacts. In February 1965, Ranger 8 swept an oblique course over the south of Oceanus Procellarum and Mare Nubium, to crash in Mare Tranquillitatis about 70 kilometers (43 mi) distant from where Apollo 11 would land 4½ years later. It took more than 7,000 images, covering a wider area and reinforcing the conclusions from Ranger 7. About a month later, Ranger 9 came down in the 90-kilometer (56-mile) diameter crater Alphonsus. Its 5,800 images, nested concentrically and taking advantage of very low-level sunlight, provided strong confirmation of the crater-on-crater, gently rolling contours of the lunar surface.
== See also == Apollo program Luna programme Lunar Orbiter program Pioneer program Surveyor program Timeline of Solar System exploration
== References ==
== External links ==
Lunar Impact: A History of Project Ranger (PDF) 1977 Lunar Impact: A History of Project Ranger (HTML) Both links lead to a whole book on the program. For the HTML one, scroll down to see the table of contents link.
Ranger Program Page by NASA's Solar System Exploration Exploring the Moon: The Ranger Program Ranger Photography of the Moon Lunar and Planetary Institute NASA History Series Publications (many of which are on-line)