One of the most successful series of manned flights, insofar as photos taken, was the Apollo Program. The first six were unmanned tests but from Apollo 7 through 17 (most destined for the Moon) Earth photography was always a prime consideration during the phase of the mission when the globe was being circumnavigated. One task in particular, on Apollo 9, known as the SO65 experiment, employed an array of 4 Hasselblad cameras mounted against a spacecraft window. Three black and white photos taken through filters of different color, and a color IR film product, helped to test ideas about multispectral space imagery that were a precursor to the ERTS program.

### Apollo Photography

The Apollo Program was an umbrella label that included the Gemini, Skylab, and Apollo-Soyuz Projects. Two Apollo manned missions, Apollos 7 and 9, stayed entirely in low-Earth orbit. The remainder of the Apollo missions always started by circling the Earth and then blasting off to the Moon. Photography of Earth thus was always done, on a limited basis, before Apollos 8, 10, 11, 12, 13, 14, 15, 16, and 17 began their lunar voyages.

Apollo 7, in 1968, commanded by Wally Schirra, was the first flight test of the Command and Service Module. During the 11 days in orbit, the crew took about 500 photographs of Earth, again using color film in Hasselblad cameras. This scene looking southwest shows the Salton Sea and Imperial Valley, with the Peninsular Ranges of southern California in the background and block fault mountains in southwest Arizona and California's Mojave Desert in the lower part.

12-5: The U.S.-Mexican border is visually evident in this photo. What defines this boundary?ANSWER

Although of excellent quality, the Apollo 7 pictures never received detailed analysis, because of the tight flight schedule involving the first lunar trip in Apollo 8.

The Apollo 8 trip, famed for its broadcast of greetings on Christmas Eve of 1968 as the crew circled the Moon, was something of an improvisation to test the Saturn V launch vehicle before the Lunar Module was ready for flight. Another goal was to insure that the Soviet Union's Zond spacecraft did not make the first lunar mission (see Shepard and Slayton, 1994) *. As the first manned mission ever to reach escape velocity, it had enormous impact worldwide. The hand-held 70mm photographs, including the first color pictures of the Earth rising from the limb of the Moon, were truly historic. They took scores of lunar surface photos, and, although coverage was sporadic, compared to the pictures from the five Lunar Orbiter missions, they proved fascinating to the public and scientists alike.

The first manned flight of the complete stack, i.e., Saturn V booster with all components or stages, was the low-Earth orbit, Apollo 9 mission. After completing tests of the Lunar Module, the crew, commanded by Col. J.A. McDivitt, acquired more than 1,100 70mm color photos of Earth, using single, hand-held cameras. Apollo 9 included an entry into the space environment by Dave Scott in his flight suit; astronaut Rusty Schweikart took the picture. In principle, the astronauts on EVA could also do photography but normally were busy with other tasks.

As an example of Apollo 9 photography, check this shot, looking north along coastal plains that extend over much of the East Coast of the U.S, with North Carolina in the foreground, the Delmarva and Delaware Peninsulas in the middle, and Long Island near the top right.

Another Apollo 9 photo covers a part of the Texas Panhandle and eastern New Mexico. The High Great Plains lies to the east, where large, irregular-shaped farms are scattered midst barren land. Almost fully barren is the fluvial sediment-covered end of the Llano Estacado (Staked Plains (center), bounded on the west by the Mescalero Escarpment. Little farming is done further west, on the Pecos Plains, until the Pecos River itself is reached (left side).

Furthermore, the Apollo 9 astronauts did a film rehearsal of ERTS (Landsat), employing coaxially-mounted 70mm cameras with color and black and white film, to produce multispectral terrain photographs, as part of the S065 experiment (Lowman, 1980) *. The montage of four photos that cover San Diego and the California/Mexico Peninsular Ranges includes the following filters: upper left: false color infrared; upper right: green filter; lower left: red filter; lower right: black and white infrared.

The writer (PDF), in his role as a Principal Investigator in this experiment, used these pictures, along with ground truth and geological map data, to generate this interpretive sketch map:

The Apollo 9 mission was the most productive flown to that time, yielding superb pictures, some of which to this day are the best records from space of certain areas. Some people suggest that Earth's atmosphere was actually clearer in 1969 than when Shuttle missions began some years later. For example, the Amazon Basin, a "blue ocean" in the words of the Gemini 9 astronauts, was by the 1990s generally obscured from smoke rising from massive land clearing.

Before heading for its historic landing on the Moon, one of the last pictures taken from Apollo 11 showed a partial Earth view of much of the U.S. Pacific Northwest into western Canada. Thus:

Geostationary weather satellites, Galileo, and other spacecraft have returned great pictures of the full Earth from space. But, still ranking number one (in request popularity) is this photo of our planet, showing Africa and surrounding oceans, taken during Apollo 17's return from the final manned mission to our lunar neighbor.

12-6: Why does the middle third of Africa appear dark compared to, say, the African desert (Sahel) to the north? ANSWER

Collectively, the deep space Apollo views of Earth have been credited as a major force in stimulating the environmental movements of the 1960s and later, by reminding us of the incredible isolation of this blue and white planet in the blackness of space.

The six Apollo lunar landing missions also returned enormous numbers of photographs of Earth's satellite from lunar orbit and on the surface. Masursky, et. al., published a good collection of these in 1978 *. Here are two Apollo 16 examples: an oblique photo (top) that shows the impact crater Aristarchus and a neighboring crater of probable volcanic origin, as attested by its lack of a central peak and terraces, and the large (Schroeter's) rille traced to it; and (bottom) a near vertical close-up of Tsiliokovsky Crater on the lunar farside.

Nicholas M. Short, Sr. email: nmshort@ptd.net

Dr. Paul D. Lowman Jr. (lowman@denali.gsfc.nasa.gov)