Deke Slayton had announced the prime and backup crews for Apollo 15 on 26 March 1970, two weeks before the launch of Apollo 14. For the prime crew, he selected astronauts with previous backup crew or prime crew experience. David R. Scott was selected as mission Commander, Jim Irwin as Lunar Module Pilot, and Alfred Worden as Command Module Pilot. For the backup crew he named Richard F. Gordon as Commander, Jack Schmitt as Lunar Module Pilot and Vance D. Brand as Command Module Pilot. Later that year, the Apollo Site Selection Board had some tough decisions to make. The plunging NASA budget put pressure on the future missions planned, and there were necessary casualties. Apollo 15 and 19 were cancelled in September 1970 and the remaining missions renumbered. Apollo 18 was also in jeopardy. The Manned Spacecraft Center suggested to the Apollo Site Selection Board that the Hadley-Apennine region, located on the southeast edge of the Mare Imbrium (Sea of Rains) and named for the British scientist and mathematician John Hadley (1682-1744), was a rich geologic choice, but there was keen interest in the Marius Hills as a possible site for the new Apollo 15 mission. As happened with several other chosen sites, there were champions for each option and the Board could not make an unarguable decision. Col. David Scott, who had only recently been selected as Commander for Apollo 15, stated that he preferred Hadley, but felt confident that he could land at either site. This broke the impasse, and the ASSB recommended the Hadley region with its distinctive rille and towering Apennine Mountains for a landing sometime between July and September 1971.
Eugene Shoemaker of the USGS had written the proposals submitted to NASA for the lunar surface sampling and photography tasks for Apollo 11, 12 and 13, as principal investigator. Shoemaker asked Gordon Swann to be a co-investigator for these missions and it was this experience that eventually led to his responsibilities for Apollo 14 and 15. At the time Apollo 11 through 13 flew, Shoemaker had left the USGS and taken a professorship at Caltech. He left the operation of these missions, in a lunar geology sense, to Swann.
"He told me I was to run some things for him," Swann recalled. "We had had a long thing going with trying to set up where we could have a presence in the Mission
Control Center and some input during the mission, which we were successful in doing. I was highly involved with that part. Gene just kind of dropped it on me, saying, 'You put together the actual working crew for the experiments that will be in the control center during the missions,' so I did. Then NASA put out an RFP (Request for Proposals) for the rest of the missions. Originally, 14 and 15 were going to be walking missions and 16, 17 and 18 would be missions with the rover. So I proposed for 14 and 15 and Bill proposed for the rover missions. Well, NASA cancelled 18 and decided to fly the rover on 15. Should that be Bill's or should that be mine? Bill and I talked it over for a few minutes and Bill said, 'Why don't we just divide them? You take 14 and 15, and I'll take 16 and 17.' So that's what we did.
''The proposal for 15 was primarily to do the field geology part,'' Swann continued, ''going out and taking photographs, the sampling, the descriptions and doing our best to decipher the geologic history of the Moon. We had a lot of responsibility to see that samples were taken that would satisfy however many investigators there were for them. We developed, pretty much at NASA's insistence -
that is, the Manned Spacecraft Center's insistence - these traverses. The field geology bunch and some NASA people, including Jack Sevier particularly and the astronauts, worked out these pre-planned traverses. NASA looked at everything in an engineering sense against a timeline - how long it would take to perform a certain task. Field geologists don't work that way, so we had to try to make the best guess that they could do these tasks and get the information necessary in 'X' number of minutes and how long it would take to get to the next place. That's where Jack Sevier of the MSC really came in and got the scientists working together on this stuff.
''On 15,'' Swann stated, ''the co-investigators included Bill Muehlberger from the University of Texas at Austin, Jim Head from BellComm, and Lee Silver from Caltech. From the USGS there was Jerry Schaber, who was also involved in traverse planning and crew briefing, Tim Hart, Robert Sutton, George Ulrich and Ed Wolfe. We also had two or three other people we called team members, who were non-geologists that supported the preparation for and during the mission. These included Ray Batson of the USGS who was responsible for photogrammetry and the inventor of gnomon, and Johnny Nutall, who took care of all the electronics of the field tests, and had a job in the Mission Control Center.''
All geologic training would now be focused around the Hadley region. Apollo 15 would be the first of the extended ''J'' missions, which included the Lunar Rover. Mission planners would spend the next sixteen months planning practically every minute of every hour, from the moment of liftoff to the moment of splashdown.
The thoroughness of mission planning and establishing mission rules were just two of the reasons for the success of project Apollo. There were, in fact, a countless number of things that could go wrong at any time in the mission. The mission team tried to account for most of these and to have contingency plans available. Apollo 13 was an example of such a failure (the explosion of the No. 2 cryogenic oxygen tank ruptured the No. 1 cryogenic oxygen tank in the Service Module) and that did indeed mean a very bad day for the crew. Even here, the resourcefulness of the mission team produced backup procedures and emergency measures that preserved the crew and the spacecraft and made Apollo 13 a triumphant success instead of a tragic failure. With the Lunar Roving Vehicle and the extended nature of Apollo 15, the mission rules were even longer and more involved. There were many ''firsts'' for Apollo 15, and a great deal to be accomplished. The purpose of mission rules is to avoid the temptation of deviating from them even when the mission is going well.
''We developed a lot of mission rules for the rover,'' Dave Scott said in the interview with this author. ''Part of the pre-flight exercise - our activities pre-flight -was not only developing these procedures to say who gets on first or what emergency procedures do we have in case this fails or that fails, but also writing the mission rules. We would all sit down with the flight director and go through all the ''what ifs'' with the rover so that if we did have a problem, we'd have a mission rule. In that philosophy, you pretty much exclude double failures. As an example, you exclude the failure of the rover and a failure of one of the astronauts' backpacks (PLSS -
Personal Life Support System) because if you have that kind of failure, one guy doesn't get back. You can walk back with two backpacks if the rover fails, and that's how you define the distance you can go from the LM, which is time-dependent on your oxygen supply.
"If you get to the limit of your oxygen supply,'' Scott continued, "Mission Control would start you back so that if the rover failed at any point, you could walk back. At the same time, the other factor in that is if one of the backpacks fails, you could have the buddy's list and you would tie the cooling hose together. You would have the OPS for oxygen, and you would drive back. That was another limit Mission Control had to watch in terms of how far away we were. But, if you had a rover failure and a backpack failure, you had a bad day. That was a double failure, and you get to the point where you can't cover everything. That was the beauty of the exercise of developing mission rules. It allows you to go through all those ''what ifs'' with all the smart guys in the room. You would have twelve to fifteen guys, each of whom would be an expert in some part of the system, and you would spend several hours going through the ''what ifs.'' Everybody makes their input, you write down the mission rules and then you are pretty well prepared.''
Three primary EVAs were planned for Apollo 15 at the Hadley-Apennine region of the Moon. During the first EVA, Scott and Irwin would drive the LRV over to Hadley Rille and drive along the edge until they got to Station 1 near Elbow Crater. Their next stop would take them to Station 2 close to the rim of St. George Crater at the base of Hadley Delta. Then they would travel to Station 3, where they would continue to take samples and photographs. Next, they would drive back to the LM Falcon and deploy the various surface experiment packages. The following day, EVA-2 would take them past a crater region known as the South Cluster and on to the base of the Apennine Front. From there they would travel to Front Crater, and loop back following a parallel traverse, again passing the South Cluster as they made for Index Crater and finally back to the LM. On their third and last day on the Moon, EVA-3 would take them to Hadley Rille, where they would make three station stops along The Terrace, as it was called. Then they would make the traverse up to the Chain Crater cluster, on to Eagle Crest Crater and the North Complex that
included the massive 750-meter Crater, then across the Hadley Plains back to the LM.
The Apollo 15 Press Kit handed out to eager reporters on 15 July was the largest ever presented to the media - over 160 pages long. It stated that the mission would "Double the time and extend tenfold the range of lunar surface exploration as compared with earlier missions." Among the obvious advantages of having the LRV was the access to more tools, greater sample carrying capacity and much more geologic exploration capability. The astronauts' improved PLSS increased the total EVA duration from eighteen to forty hours, which meant that the astronauts could remain outside on a single EVA for almost twice as long as on previous missions. The LM was modified with larger oxygen and water tanks (and a more powerful descent engine) to accommodate nearly doubling the stay on the Moon from thirty-seven to sixty-seven hours. The press kit's description of the landing site in particular is worth quoting at length:
"The Apollo 15 landing site is located at 26 degrees 4 minutes 54 seconds North latitude by 3 degrees 39 minutes 30 seconds East longitude at the foot of the Apennine mountain range. The Apennines rise up to more than 15,000 feet along the southeastern edge of the Mare Imbrium (Sea of Rains).
"The Apennine escarpment - the highest on the Moon - is higher above the flatlands than the east face of the Sierra Nevadas in California and the Himalayan front rising above the plains of India and Nepal. The landing site has been selected to allow astronauts Scott and Irwin to drive from the LM to the Apennine front during two of the EVAs.
"A meandering canyon, Rima Hadley (Hadley Rille), approaches the Apennine front near the landing site and the combination of lurain (lunar terrain) provides an opportunity for the crew to explore and sample a mare basin, a mountain front and a lunar rille in a single mission.
"Hadley Rille is a V-shaped gorge paralleling the Apennines along the eastern edge of Mare Imbrium. The Rille meanders down from an elongated depression in the mountains and across the Palus Putredenis (Swamp of Decay), merging with a second rille about 62 miles (100 kilometers) to the north. Hadley Rille averages about a kilometer-and-a-half in width and about 1,300 feet (400 meters) in depth throughout most of its length.''
The press kit devoted twenty-four pages to the LRV, including its telecommunications equipment. Indeed, the Hadley-Apennine landing site would prove to be a very wise choice from a lunar geology standpoint, and the Lunar Roving Vehicle would permit the astronauts the maximum opportunity to explore its many secrets. The LRV and what it would allow Scott and Irwin to do on the Moon was responsible for sparking renewed interest in the last Apollo missions. Mission planners were banking on the LRV performing as advertised and that the RCA TV camera, which could be remotely controlled from Houston, would beam back images that would justify to incredulous Americans that it was worth all the expense.
"Hadley Rille had to be the most interesting geologically,'' Irwin wrote, "because of the rocks themselves and the dramatic site, tucked in among those high
mountains. We strongly supported the selection of the Rille as a landing site for 15, and we were delighted when this choice was made''
Was this article helpful?