The original concept of the Apollo spacecraft by North American Aviation, Inc.

The original concept of the Apollo spacecraft by North American Aviation, Inc. The previously classified document SID 61-280 (NASA Project Apollo Spacecraft, Volume 1 - Technical Proposal) dated October 6, 1961.
The document guesses the features of a later version of the Apollo spacecraft flying from 1966 to 1975. The original Command Module design is especially similar - its 1961 design differs little from the last version presented by NASA in January 1964 (Apollo Spacecraft Block I & Block II for Saturn-1B and Saturn-5 launch vehicles ):




The service module (Service Module) had the most notable difference: in 1961, it was not supposed to install a powerful SPS liquid propellant rocket engine (Aerojet General AJ10-137), since the ship was not designed for independent braking to go to lunar orbit and coming off her. Until 1962, while American engineer John Hubolt from the Langley Research Center did not propose to NASA the idea of ​​approaching a circumlunar orbit (LOR - Lunar-Orbit Rendezvous *), the idea of ​​direct flight to the lunar surface (Direct Ascent), which would be carried out with the help of one launch of the super-powerful carrier rocket “Nova” **, more powerful than the “Saturn S-5”:
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Scheme of the Apollo spacecraft sample 1961 for a direct flight to the moon (method Direct Ascent)


So, NASA represented the landing on the moon in 1961 of the Apollo spacecraft using the direct ascent to the lunar surface (Direct Ascent)


Model of the spacecraft "Apollo" sample 1961 for a direct flight to the moon (method Direct Ascent)


Comparison of carrier rockets "Saturn S-1", "Saturn S-5" and "Nova". Poster of the George Marshall Space Flight Center of April 11, 1962. Poster NASA MSFC-9902050


NASA engineer John Hoebolt justifies the mass savings of the Apollo spacecraft for a method with convergence in circumlunar orbit (LOR - Lunar Orbit Rendezvous). The picture was taken July 24, 1962. Photo by NASA L-1962-05848


Evolution of the Apollo spacecraft from 1960 to 1962. NASA drawing

The idea of ​​approaching a circumlunar orbit was more progressive, since it involved substantial savings in the mass of the spacecraft. It was taken as the basis in 1962, completely reworking the concept of flights to the moon, carried out under the Apollo program. The refusal of a heavy ship that carried out a direct flight using Direct Ascent allowed NASA to stop using the Saturn C-5 launch vehicle (later designated simply Saturn-5), which had already been tested as separate components (fire tests of F-1 and J-2 engines, static and dynamic tests of rocket units S-IC, S-II and S-IVB) at the George Marshall Space Flight Center (MSFC). The project “Nova” remained on paper.
Copies of SID 61-280 were sent out in 1961 for study at various NASA centers. Archive North American Aviation, Inc., after its abolition in 1996, was transferred to the company The Boeing Company. Only a part of this unique historical document was scanned, since the rest of the pages were lost. Part of the surviving document got into the archives of the San Diego Air & Space Museum, where it was recently discovered and translated into electronic form (the original is of course in English).

© Sergey Vyatkin, 2014

* - this idea belongs to the Soviet scientist Yury Vasilyevich Kondratyuk (pseudonym of Alexander Ignatievich Shargey), one of the founders of cosmonautics. LOR in the USA is called Kondratyuk's Route.

** - a method with a multi-launch scheme with an assembly from separate modules of the Apollo spacecraft directly in a near-earth orbit, also performing, after entering the flight path to the Moon, a direct flight to the lunar surface was also considered. The method was called EOR (Earth-Orbit Rendezvous) and involved the use of up to 15 Saturn S-1 launch vehicles, the “weakest” in the family of Saturn and Nova launch vehicles.