Chariots for Apollo: A History of Manned Lunar Spacecraft|
Influences on Booster Determination
Concurrently with the agreement that Gilruth should get started on the spacecraft development contract, Associate Administrator Seamans realized that it was time to decide what the rest of the Apollo stack should comprise. The method chosen for the lunar trip - rendezvous or direct ascent - would affect Apollo's costs and schedules, as well as the launch vehicle configuration.
A launch vehicle to support the moon landing was a big question mark when the President issued his challenge in May 1961. The Space Task Group wanted to get its opinions on the record - not really sure how big a vehicle would be needed but rather hoping that NASA would develop the Nova. Marshall wanted to build a big liquid-fueled rocket but was a little chary about tackling a vehicle the size of Nova. One aspect that caused the Huntsville center to hold back was the high cost projected for the F-1 engines. When he learned of Huntsville's misgivings, Max Faget suggested that solid-fueled rockets be used for the first stage.
Faget thought the first stage should consist of four solid-fueled engines, 6.6 meters in diameter; these could certainly accomplish whatever mission was required of either the Saturn or Nova, whichever was chosen, at a reasonable cost. It made good sense, he said, to use cheap solid fuels for expendable rockets and more expensive liquid fuels for reusable engines. "We called the individual solid rocket 'the Tiger' because we figured it would be a noisy animal and would roar like a tiger," Faget remembered. But he and his group could not sell their idea. Liquids were preferred by both Headquarters and Marshall, who insisted that the solids were too heavy to move from the casting pit to the launch pad. They also argued, he said, that solids had poor burning characteristics and were unstable. So the launch vehicle question dragged on, although pressure to make some sort of decision did not lessen.33
After the Fleming and Lundin Committee study reports had been distributed, Seamans met with several Headquarters program directors to discuss whether the advanced Saturn, called the C-3, recommended by Lundin's team could make the voyage to the moon if the earth-orbital rendezvous approach were chosen. Silverstein warned that the vehicle's upper stages were simply not well enough defined as yet.34 Seamans agreed. On 20 June 1961, he asked Colonel Donald H. Heaton to head a task force* to study the C-3 and its possible employment in a manned lunar landing mission using rendezvous techniques.35
Heaton's group followed Fleming's lead in narrowing the scope of its investigations to a single mode - in this case, earth-orbital rendezvous - as the way to go. Most of the members agreed that this mode offered the earliest chance for a landing. Either the C-3 or its next larger version, a C-4, could be used. But the team urged that NASA begin work on the C-4, because it "should offer a higher probability of an earlier successful manned lunar landing than the C-3." Moreover, a rendezvous capability would enable the C-4 to cope with future payload increases that the direct-ascent, Nova-class booster, with its fixed thrust, would be unable to handle.36
On 22 June 1961, Webb and Dryden met with several of their top lieutenants to see what useful items could be gleaned from the reports of all these committees for charting Apollo's strategy. Abraham Hyatt, the new chief of Plans and Programs, criticized any plan that required development of two launch vehicles, one for circumlunar missions and another for direct flight. Hyatt suggested that NASA either build a huge launch vehicle with as many as eight F-1 engines in the first stage for both circumlunar flight and lunar landing or cluster half that number of these engines in a somewhat smaller vehicle and use rendezvous techniques.37
This meeting did produce several significant program decisions. Most important was the order for Marshall to stop work on the C-2, begin preliminary design on the C-3, and continue studies of a much larger vehicle for lunar landing missions. (By this time, what constituted a Saturn, in any of its versions, or a Nova was becoming hard to understand. For some clarification of the confusion, see the accompanying list.)38
Early in July, Seamans appointed a Lunar Landing Steering Committee,** with himself as chairman, to meet every Monday afternoon until an impending Headquarters reorganization was completed. During its three meetings in July, the committee considered the facilities and organization needed to manage Apollo and then turned its attention to launch vehicles. But nothing tangible emerged from these discussions, either, certainly no hardbound decision on a launch vehicle for Apollo.39
Apollo Launch Vehicles
Saturn C-1 (renamed Saturn I).*Configuration: S-1 booster (eight H-1 engines, clustered, with 6.7-million-newton [1.5-million-pound] combined thrust), S-IV second stage (four engines using liquid-hydrogen and liquid-oxygen propellants, with 355,800-newton [80,000-pound] total thrust), and S-V third stage (two engines like those in the S-IV stage, with 177,900-newton [40,000-pound] total). In March 1961, NASA approved a change in the S-IV stage to six engines that, though less powerful individually, delivered 400,300-newtons (90,000-pound thrust) collectively. On 1 June 1961, the S-V was dropped from the configuration.
Saturn C-1B (renamed Saturn IB).*Configuration: S-IB booster (eight clustered uprated H-1 engines with 7.1-million-newton [1.6-million-pound] total thrust) and S-IVB second stage (one J-2 engine with 889,600 newtons [200,000 pounds]). On 11 July 1962, NASA announced that the C-IB would launch unmanned and manned Apollo spacecraft into earth orbit.
Saturn C-2.Four-stage configuration: S-I booster, S-II second stage (not defined), S-IV third stage, and S-V fourth stage.
Three-stage configuration: S-I booster, S-II second stage (not defined), and S-IV third stage. Plans for the C-2 were canceled in June 1961 in favor of the proposed C-3.
Saturn C-3.Configuration: booster stage (two F-1 engines with a combined thrust of 13.3 million newtons [3 million pounds]), second stage (four J-2 engines with a 3.6-million-newton total [800,000 pounds]), and S-IV third stage. Plans for the C-3 were canceled for a more powerful launch vehicle.
Saturn C-4.Configuration: booster stage (four clustered F-1 engines with 26.7-million-newton [6-million-pound] combined thrust) and a second stage (four J-2 engines with combined thrust of 3.6 million newtons [800,000 pounds]). The C-4 was briefly considered but rejected for the C-5.
Saturn C-5 (renamed Saturn V).*Configuration: S-IC booster (five F-1 engines, clustered, with total thrust of 33.4 million newtons [7.5 million pounds]), S-II second stage (five J-2 engines with total of 4.5 million newtons [1 million pounds]), and S-IVB third stage.
Saturn C-8.Configuration: First stage (eight F-1 engines, clustered, with a combined 53.4 million newtons [12-million-pound thrust]), second stage (eight J-2 engines with total of 7.1 million newtons [1.6 million pounds]), and third stage (one J-2 engine with 889,600 newtons [200,000 pounds]).
Nova.Configuration: several proposed, all using F-1 engines in the first stage. One typical configuration consisted of a first stage (eight F-1 engines, clustered, with 53.4-million-newton [12-million-pound] total thrust), a second stage (four liquid-hydrogen M-1 engines with combined thrust of 21.4 million newtons [4.8 million pounds]), and a third stage (one J-2 engine with 889,600 newtons [200,000 pounds]). Nuclear upper stages were also proposed.
*Only the three vehicles indicated by an asterisk were actually developed and flown in the Apollo program.
* Heaton's committee was made up of Commander L. E. Baird (Navy); Richard B. Canright, Norman Rafel, Joseph E. McGolrick, L. H. Glassman, John L. Hammersmith, Robert D. Briskman, James Nolan, Warren North, and William H. Woodward (NASA Headquarters); Wilson B. Schramm, R. Voss, Paul J. DeFries, Heinz Koelle, and Harry Ruppe (Marshall); William H. Phillips and John Houbolt (Langley); Hubert M. Drake (Flight Research Center); and J. Yolles (Air Force Systems Command).
** The steering committee attendance was flexible; the only members who met regularly were Seamans, Don Ostrander, Ray Romatowski, and Fleming (committee secretary). Less frequent attendees were Silverstein, Ira Abbott, Hyatt, DeMarquis D. Wyatt, Nicholas E. Golovin, Alfred Mayo, G. Dale Smith, John D. Young, Charles H. Roadman, Low, Milton W. Rosen, and Wesley Hjornevik (all of Headquarters); Eberhard F. M. Rees and Hans H. Mans (of Marshall); and Gilruth (STG).
33. Faget, interview, comments on draft edition of this volume, Houston, 22 Nov. 1976.
34. DeMarquis D. Wyatt memo for record, "Discussions with the Associate Administrator on June 15, 1961," 20 June 1961.
35. Seamans to Dirs., Launch Vehicle Prog., et al., "Establishment of Ad Hoc Task Group for Manned Lunar Landing by Rendezvous Techniques," 20 June 1961.
36. NASA, "Earth Orbital Rendezvous for an Early Manned Lunar Landing," pt. I, "Summary Report of Ad Hoc Task Group Study" [Heaton Report], August 1961.
37. Abraham Hyatt, "Proposed Items for Discussion at Meeting on 22 June 1961," 20 June 1961; Hyatt to Seamans, "Comments on Arthur Kantrowitz's paper very glamorously titled 'Space Strategy for America,'" 20 June 1961.
38. "Composite Notes on June 22, 1961 Meeting"; MSFC, "Saturn Project Fact Sheet," 1 June 1961; David S. Akens, Saturn Illustrated Chronology: Saturn's First Eleven Years, April 1957 through April 1968, 5th ed., MHR-5 (Huntsville, Ala.: MSFC, 20 Jan. 1971), p. 4; James E. Webb memo for record, "Selection of Contractors to Participate in Second Phase of SATURN S-II Stage Competition," 8 June 1961; Ertel and Morse, Apollo Spacecraft Chronology, I: 234-35.
39. Seamans to Admin., NASA, "Proposed Interim Procedures for Implementing the Lunar Landing Program," 7 July 1964; Maj. Gen. Don R. Ostrander memo, "Manned Lunar Landing Program," 10 July 1961, with enc.; William A. Fleming, secy., "Discussion Notes: First Meeting of Manned Lunar Landing Steering Committee," 6 July, "Second Meeting," 17 July, and "Third Meeting," 31 July 1961; Low to Dir., Space Flight Prog., "Meeting of Manned Lunar Landing Coordination Group," 8 July 1961