Robot Scouts

The words

1. Alphonsus

   Ranger 9 ended its flight inside Alphonsus, a lunar crater. Its approaching views were broadcast to television audiences on Earth, showing the surface in increasing detail before impact.

   NASA: Ranger photographs the Moon (opens a new tab)

2. Copernicus

   Lunar Orbiter 2’s 1966 view of Copernicus looked across the crater rather than straight down. This slanting perspective revealed the shape of the Moon’s rugged terrain.

   NASA: the Lunar Orbiter program (opens a new tab)

3. Flamsteed

   Surveyor 1 touched down inside Flamsteed P in the Ocean of Storms on June 2, 1966. Photographs of its footpad showed how the surface supported the landed spacecraft.

   NASA: Surveyor 1 lands on the Moon (opens a new tab)

4. Gerard Kuiper

   Gerard Kuiper, an astronomer at the University of Arizona, was Ranger’s principal investigator. He also worked on Surveyor and helped identify Apollo landing sites, linking lunar photography with landing preparation.

   Arizona: Gerard Kuiper’s lunar work (opens a new tab)

5. Kodak

   Eastman Kodak supplied Lunar Orbiter’s photographic system. Film was exposed and developed aboard the spacecraft, then scanned so its images could be transmitted to Earth as radio signals.

   Did you know?

   Two lenses exposed the same roll of film at once, recording a detailed narrow view and a wider view of the surrounding terrain.

   NASA: Lunar Orbiter’s cameras and gravity (opens a new tab)

6. Landing Sites

   The first three Lunar Orbiters examined possible Apollo landing areas from above. Surveyor’s close-up observations added ground-level evidence, helping planners judge places before sending astronauts.

   NASA: the Lunar Orbiter program (opens a new tab) · NASA: Surveyor 1 lands on the Moon (opens a new tab)

7. Lunar Orbiter

   Five Lunar Orbiters photographed the Moon during 1966 and 1967. The early missions surveyed possible Apollo landing sites; later spacecraft extended the mapping to much of the far side.

   NASA: the Lunar Orbiter program (opens a new tab)

8. Mare Cognitum

   After Ranger 7 returned its close-up pictures in July 1964, the impact region was named Mare Cognitum. The name commemorated a lunar landscape newly seen in detail.

   NASA: Ranger photographs the Moon (opens a new tab)

9. Mascons

   Lunar Orbiter tracking helped reveal irregularities in the Moon’s gravity. These concentrations of mass disturbed spacecraft paths and mattered when planning Apollo’s precise rendezvous and docking maneuvers.

   NASA: Lunar Orbiter’s cameras and gravity (opens a new tab)

10. Ranger

    Ranger 7, 8 and 9 sent close-up television pictures as they descended toward the Moon. Each mission ended in impact, unlike the later Surveyors’ soft landings.

    NASA: Ranger photographs the Moon (opens a new tab)

11. Scoop

    Surveyors 3 and 7 carried a mechanical scoop that dug trenches in lunar soil. The tool let investigators examine the ground directly instead of relying only on photographs.

    NASA: Surveyor’s surface samplers (opens a new tab)

12. Soil Mechanics

    Surveyor 7’s soil tests examined whether the ground could support weight. Its arm-mounted scoop dug trenches and carried out surface-bearing tests, extending the investigation below the photographed surface.

    NASA: Surveyor 7 near Tycho (opens a new tab)

13. Surveyor

    Surveyor landers sent photographs and surface information from the Moon before Apollo. Surveyor 1 made the first successful American soft landing there on June 2, 1966.

    Did you know?

    Surveyor 1’s camera used red, green and blue filters. Engineers on Earth combined pictures taken through them to reconstruct color views of the lunar surface.

    NASA: Surveyor 1 lands on the Moon (opens a new tab)

14. Tycho

    Surveyor 7 landed north of Tycho’s rim on January 10, 1968. Unlike the earlier Surveyors, it explored rougher terrain beyond the candidate sites for early Apollo landings.

    NASA: Surveyor 7 near Tycho (opens a new tab)

15. Vidicon

    A light-sensitive tube used in an early television camera.

    Ranger 7’s Camera A used a vidicon to record the approaching Moon. Its final frame revealed small impact craters scattered across the lunar plain.

    NASA: Ranger 7’s final Camera A image (opens a new tab) · NASA: how a vidicon worked (opens a new tab)