Landsat and Apollo: The Forgotten Legacy Paul D. Lowman, Jr. Abstract 8 and MA-~),the pilots (W.M. Schirra and L.G. Cooper) This paper demonstrates that Landsat was fundamentally a carried out hand-held 70-mm terrain photography for geo- result of the Apollo Program. The U.S. Geological Survey's logic purposes (O'Keefe et al., 1963), suggested by P.M. Meri- EROS proposal of 1966, which eventually led to Landsat, was field on the basis of his analyses of sounding rocket stimulated largely by the demonstrated utility of 1100 orbital photography (Merifield and Rammelkamp, 1964). With a long photographs from the Gemini missions, Gemini being solely (22-orbit) mission, Cooper had the opportunity to obtain 29 preparation for Apollo. In addition, Earth-oriented remote 70-mm color photographs, chiefly of southern Asia. These sensing research sponsored by NASA in the mid-1960s, pri- photographs, backed by Cooper's seemingly incredible visual marily support for Apollo lunar missions, included studies of observations, were one of the main scientific results of Pro- Earth resource applications as well. Finally, the extensive se- ject Mercury (Lowman, 1965). They were displayed at a 1964 ries of airborne remote sensing studies carried out by the UNESCO remote sensing conference in Toulouse, triggering NASA Manned Spacecraft Center was Apollo-derived in that world-wide interest, and termed by the late W.A. Fischer the primary mission of MSG was to accomplish a lunar land- "the high point of the meeting." The Mercury program ing. It is concluded that, had it not been for the Apollo Pro- ended with the MA-9 mission in 1963, but the Mercury pho- gram, Landsat or its equivalent would have been delayed by tographs led directly to the SO05 Synoptic Terrain Photogra- 10 years or more. phy Experiment (Lowman, 1969), carried on the two-man As it recedes into history, the Apollo Program is increas- Gemini flights beginning in 1965. ingly regarded as a heroic effort, but one that did little more It is at this point that the link between Apollo and Land- than put flags and footprints on the Moon. There is virtually sat emerges clearly. The Gemini Program, started after Presi- no realization that one of Apollo's most fundamental results, dent Kennedy's 1961 proposal for a lunar landing, was an too important to be trivialized as "spinoff," was the Landsat intensive effort to develop the technology and operational Program. Two recent reviews of Landsat's history (Lauer et techniques for lunar missions. Despite its separate designa- al., 1997; Mack and Williamson, 1998) make little or no tion, and the supeficial resemblance of the Gemini space- mention of Apollo, although Mack's (1990) earlier treatment craft to the Mercury capsules, Gemini was an integral part of briefly summarized the impact of Gemini photography. These Apollo. It produced a broad technological infrastructure and and similar publications, such as Vincent's (1997) authorita- extensive experience in orbital rendezvous and extravehicu- tive remote sensing text, give a misleading impression of lar activity. However, the Gemini astronauts also carried out how Landsat actually arose. a wide range of scientific experiments, one of them synoptic The purpose of this note is to set the record straight for terrain photography. On the first long (4-day) mission, J.A. the remote sensing community, for more reasons than simple McDivitt and the late E.H. White took, among others, a series historical accuracy. The Apollo Program was in its day widely of 39 overlapping near-vertical color pictures from Baja Cali- criticized by scientists, including several Nobel laureates, on fornia to central Texas (Lowman et al., 1966). All ten Gemini the grounds that unmanned spacecraft would be just as effec- missions, except the aborted GT-8,produced photographs tive and far less expensive. Future space efforts may be useful for geology, geography, or oceanography, eventually handicapped by this still-widespread view, typified by the totaling about 1100 (Lowman, 1969a; Lowman, 1980). Many recent statement of French space minister Claude Allegre, are unsurpassed to this day (Figure I),possibly because the criticizing the International Space Station, that he was una- Earth's atmosphere in areas such as Brazil is not as clear as ware of any important scientific discovery made by an astro- it was before deforestation began. naut (Space News, 22-28 June 1998). Published wideIy, in magazines such as the National Ge- The case for Apollo as a key element in Landsat begins ographic (Lowman, 1966) and Life, the Gemini color photo- with the statement by the late W. T. Pecora (1969), that graphs generated international interest in the potential appli- Landsat's precursor concept, the Earth Resources Observation cations of orbital imagery of the Earth's surface (Lillesand Satellite (EROS) program of the U.S. Geological Survey (USGS), and Kiefer, 1994), as distinguished fiom satellite meteorol- was "conceived in 1966 largely as a direct result of the dem- ogy, where the value of orbital sensors had already been onstrated utility of Mercury and Gemini orbital photography demonstrated. It should be emphasized here that, until the to Earth resource studies." A contemporary review of satel- mid-1960s, there was virtually no appreciation of the scien- lite imagery in this journal (Merifield et al., 1969) devoted its tific and environmental applications of orbital terrain imagery. first six pages to the "superb" Gemini and Apollo 70-mm For example, "Long Range Thinking in Space Sciences," an photographs. A similar paper, by a U~GSgeologist (Fary, internal NASA document published in October 1960, al- 1967) argued for EROS, illustrating its value with several though outlining investigations of the Earth's atmosphere, ''magnificent" Gemini photographs. However, the link be- magnetic fields, and mass distribution, said nothing about tween EROS and Apollo is a complex one, needing further discussion. The American manned space program began with Pro- Photogrammetric Engineering & Remote Sensing, ject Mercury in 1958. On the last two Mercury missions (MA- Vol. 65, No. 10, October 1999, pp. 1143-1147. 0099-1112/99/6510-1143$3.00/0 Goddard Space Flight Center (Code 921), Greenbelt, MD 8 1999 American Society for Photogrammetry 20771 ([email protected]). and Remote Sensing PHOTOGRAMMETRIC ENGINEERING 81 REMOTE SENSING October 1999 1143 man, 1996). Starting in 1963, a wide range of remote sensing studies was carried out with the support of NASA Headquar- ters under the leadership of P.C. Badgley (Lowman, 1980; Mack, 1990). Badgley coordinated remote sensing efforts for Apollo missions then being planned (Friedrnan et al., 1964), in particular, Earth-orbital Apollo Extension System (AES, later Apollo Applications Program) missions that, in effect, were eventually flown as Skylab. (He also encouraged the USGS EROS proposal.) The Earth-orbital and aircraft missions were viewed as precursors to later lunar missions (Figure 3), the terrestrial test sites being chosen for their similarity to lu- nar terrains as well as for purely terrestrial applications. The remote sensing programs developed by Badgley and his col- laborators were thus an integral part of Apollo. A similar Apollo parentage can be shown for the Earth- oriented remote sensing programs of the NASA Manned Spacecraft Center (MSC) (now the Lyndon B, Johnson Space Center), starting in the early 1960s. MSC was, of course, the lead center for the Apollo lunar landing program (as well as the Gemini missions), but it also carried out a broad program of remote sensing research using a fleet of aircraft with a va- riety of sensors. MSC was responsible for Skylab with its complement of remote sensing instruments, the eventual re- alization of AES as mentioned above. The point is that the Manned Spacecraft Center was built solely as the result of Figure 1. Gemini 12 photograph S-66-63082 (original in the decision to go to the Moon; without Apollo, there would color); view to east over the Zagros Mountains (left), have been no MSC. Strait of Hormuz, and Makran Range. Persian Gulf at It should be added that the MSC contribution to ERTS lower right. From Lowman and Tiedemann (1971). continued after the period with which this paper is primarily concerned (Amsbury, 1989; Kaltenbach, 1969a; Kalatenbach, 1969b). The unmanned Apollo 6 mission carried a fixed 70- mm camera that produced excellent stereo pairs in color the study of the planet's surface from orbit. The Mercury over the southwest U.S. and Africa. The Apollo 7 crew car- photographs began to remedy such omissions, but it was the ried out an extensive terrain photography Program with a va- sudden flood of high-resolution color photographs from Gem- riety of films and filters, returning about 200 photos useful ini that gave orbital remote sensing a jump start, so to speak, for geology. What has been called the ''most important ter- In particular, they stimulated the EROS proposal. rain photography" (Colwell, 1997) was the SO65 experiment Electronic imaging from space had been carried out on Apollo 9 in 1969. Using a set of four coaxially mounted since 1960 by various meteorological satellites beginning 70-mm cameras, astronauts McDivitt, Schweikart, and Scott with the Tires series. In 1966 RCA, who had supplied the Ti- SUCC~SS~~~~Ycarried Out a returned-film simulation for ERTS ros television cameras, approached the terrain photography (Lowman, 196913)-In addition to producing many geologi- experimenters at Goddard Space Flight Center with the pro- cally useful pictures, the So65 experiment provided a proof- posal to use the Return Beam Vidicon (RFJV) camera on a sat- of-conce~tfor ERTS. In summary, the Apollo Program not ellite to produce high resolution imagery for geological and only provided the initial stimulus for ERTS, through EROS, related purposes.