() 0 o () f) ct • • Promising Fra Mauro I97I TRY AGAIN (1970) The Apollo 13 accident put a crimp in the flight schedule but not in Deke Slayton's desire for Al Shepard to fly a lunar mission or the scientists' desire for a landing on the Fra Mauro Formation. The two desires came together in Apollo 14. Alan Bartlett Shepard, Jr., the oldest active astronaut (b. 1923), would be making his first flight since the cannonball act ten years earlier that had been Project Mercury's and the United States's first tentative step into space with a human crew. The other two crew members were from the fifth group of astro­ nauts, chosen in April 1966, and had never flown in space before . The LMP was Edgar Dean Mitchell (b. 1930, a more usual birth date for an astronaut), and the eMP was Stuart Allen Roosa (b. 1933). Both men were primarily pilots like the rest of the fifth group, but both also had degrees in aeronautical engineering, and Mitchell had a Ph.D. in aeronautics and astronautics from MIT. Their back­ ups were Gene Cernan, Joe Engle, and Ron Evans, whom the arithmetic 14 + 3 would seem to finger as the Apollo 17 prime crew. The mission scientist was Australian Phil Chapman, but he was replaced as capcom for the EVAS by the geologically knowledgeable and committed fifth-group astronaut and Apollo 13 survivor Fred Haise. Another effect of the Apollo 13 bust was a change in the landing site planned for Apollo 14. In August 1969, when Lovell's crew was picked for Apollo 13 and Shepard's for Apollo 14, a fast-paced launch schedule had still been in effect. Apollo 14 was to investigate a dark mantling deposit interpreted as volcanic ash or other pyroclastic material. Possible landing sites were at Rima Bode II (13 0 N, 40 w), a linear graben adjoining an elongated probable volcanic crater that was the blanket's pr esumed source, or a site called Littrow, which lies west of the Promising Fra Mauro 1971 247 later Apollo 17 landing site in the Taurus-Littrow Valley' Littrow had won out over Rima Bode II at a GLEP meeting in October 1969,2 and Shepard's crew trained for a Littrow landing in February 1970. Littrow was outside the equato­ rial Apollo zone but could be reached in winter. In one interpretation of the Lunar Orbiter 5 photographs of the Littrow site, the dark material seemed to blanket other mare units and a sharp ridge, so it seemed young. Here, therefore, a simple H mission could learn (I) what lunar pyroclastics are made of, (2) what gases caused them to erupt high enough to settle down as blankets, (3) what ridges are made of, and (4) how late lunar volcanism had lasted. Apollo 14 was moved to July 1970 when the launch pace eased up in 1969, then to October 1970 when Apollo 13 was delayed from March to April 1970, and eventually to February 1971 after Apollo 13 aborted. It could have gone to Littrow in that month, but now everything had changed. The loss of the Apollo 13 H-type landing meant that Apollo 14 would probably be the last H mission, though this was not decided until the developments described in chapter 15 occurred. Fra Mauro was ideally suited for an H mission. We geologists ofGLEP loved it. I remember thinking late one night in 1964 or 1965 while geologically mapping the Fra Mauro Formation in the Mare Vaporum quadrangle that my life would be complete if ever I had some crumbs from the Fra Mauro in my desk drawer. Geophysicists who wanted a large separation between ALSEPS for a passive lunar seismic network were bothered by the small separation ofonly 180 km between the intended Fra Mauro landing point and the Apollo 12 ALSEP; they preferred the distant Littrow. However, the geophysicists who were prepar­ ing an active seismometer liked the close spacing for determining local crustal structure and wished to explore the terra regolith and the seismic properties of the predicted deep material. Another factor was that a mission to Fra Mauro, but not one to Littrow, could photograph Descartes, an objective already consid­ ered important at this time. Fra Mauro and Apollo 14 belonged together like bread and butter, and Apollo 14 was retargeted to the Apollo 13 site at an ASSB meeting on 7 May 1970 . Lee Silver was asked to lead the training for Apollo 14 but was too deeply involved in his Apollo II and 12 sample studies and his courses at Caltech. Instead, the principal non-USGS and non-MSC consultant for the geologic train­ ing of the Apollo 14 crew was Richard Henry Jahns (1915-1983). Dick Jahns had spent many years at Caltech before moving first to Pennsylvania State Uni­ versity and then, in the fall of 1965, to Stanford as dean of the School ofEarth Sciences. He had long experience in teaching and administration, was president of the Geological Society ofAmerica in 1970 (Silver held the post in 1979), and had served on seemingly every geologic advisory committee in existence, includ­ ing GLEP and the geology team at the Santa Cruz conference. The Caltech- TO A ROCKY MOON Shoemaker web included Jahns, too, for Shoemaker had been his student dur­ ing his undergraduate days at Caltech and has said that Jahns influenced him far more than anyone else. It wasJahns who interested him in joining the USGS and Jahns who suggested his master's thesis area in New Mexico-whichJahns, Shoemaker, and Bill Muehlberger visited together once in 1947. Muehlberger had also been Jahns's field assistant in Vermont in 1948 and 1949. This perva­ sive web also connected non-Caltecher Chidester to the others, for he had worked with Jahns in Vermont and first met Muehlberger there. It was Jack Schmitt, however, who got Jahns into the training program. Jahns's scientific insight and interest in new initiatives coexisted with a penchant for practical jokes in the Caltech mold, which he and his students enthusiastically swapped, and in off-color jokes that he kept improving. This lack of airs seemed desirable in an instructor for Shepard.' Chidester and a dozen other SPE and MSC geologists also trained the crew in such places as Hawaii, SPE'S artificial crater fields, and, significantly as we shall see, the craters Schooner and Sedan- at the Nevada Test Site. The orbital science teams briefed the crew frequently. My turn came at the Cape on IO June, when I was supposed to summarize the geology of the Moon with an emphasis on basins. I am afraid that by this time I was too cynical about the value of such briefings to generate much enthusiasm in either myself or the crew. The academic side oflunar geology was not what was needed at this point. Obtaining approval and funding for foreign travel was a problem for the USGS, so in August 1970 MSC'S geologists took the prime and backup crews to the Ries in Germany, where so much understanding of impacts had originated. What was needed was an understanding of which rocks to collect and describe and how to do it. Shepard did not approach this education seriously, and what­ ever greater interest Mitchell may have had was subordinated to his comman­ der's attitude. However, Gordon Swann has said that the crew asked for two geologic briefings as launch time approached. The USGS published, under a new name and with some revisions, the premis ­ sion geologic maps that had been prepared for Apollo 13 by Dick Eggleton and Terry Offield.' On the more detailed map, at the I :2 5,0 0 0 scale, Offield mapped two morphologically distinct kinds of terrain they called facies, meaning a sub­ type of a rock unit, as parts of the Fra Mauro Formation, but considered a third, "smooth-terrain" unit (map symbol, Is) as possibly distinct from the impact­ generated Fra Mauro and possibly volcanic in origin. Eggleton did the same on his regional map at the I :25°,000 scale and added a smooth facies of the Fra Mauro that was subtly distinct from unit Is. Eggleton had been a dedicated Im­ briophile, but during a long leave of absence from the USGS to obtain his Ph.D. Promising Fra Mauro 249 at the University of Arizona, which was awarded at the time of Apollo 13, he had caught a touch of volcanic fever from the Lunar Orbiter photographs. The aptly named deep, sharp, and young Cone crater was the key to the mission's success. The Apollo 13 computer had been set for a landing almost 2 km west ofthe crater rim, though Jim Lovell was supposed to "redesignate" to a point only 1.25 km away if he could. For Apollo 14, this point became the computer target as well. Cone had punched into one of the typical sinuous ridges of the ridged facies, Fra Mauro par excellence. Eggleton and Offield calculated a regolith thickness on the Fra Mauro Formation of between 5 and 12m, so by all rights a 370-m-diameter crater like Cone should easily have penetrated the regolith and thrown pieces ofthe actual Fra Mauro bedrock onto the surface. The landing point itself would be on subdued craters excavated in the possibly volcanic unit Is. The geologists' interpretations would be amply tested, and the age, chemistry, and physical properties of this most important lunar rock unit, derived from deep within the Moon, would finally be learned if the LMA1ltares touched down where it was supposed to.