Lunar Orbit Rendezvous for Project Apollo 1962 NASA L-762; Basic Moon Landing Mission Plan

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An early overview of an Apollo moon landing mission, created soon after Lunar Orbit Rendezvous, instead of direct ascent or Earth Orbit Rendezvous, was chosen as the mission method in July, 1962. The configuration of the Saturn C-5 (later Saturn-V) launch vehicle was determined in December 1961.

"The Apollo spacecraft will consist of three modules: the manned Command Module; the Service Module, which contains propulsion systems; and the Lunar Excursion Module (LEM) to carry astronauts to the moon and back to the Command and Service Modules. The spacecraft will be launched via a three-stage Saturn booster. The first stage will provide 7.5 million pounds of thrust from five F-1 engines for liftoff and initial powered flight. The second stage will develop 1 million pounds of thrust from five J-2 engines to boost the spacecraft almost into Earth orbit. Immediately after ignition of the second stage, the Launch Escape System will be jettisoned. A single J-2 engine in the S4B stage will provide 200,000 pounds of thrust to place the spacecraft in an earth parking orbit. It also will be used to propel the spacecraft into a translunar trajectory, then it will separate from the Apollo Modules. Onboard propulsion systems will be used to insert the spacecraft into lunar orbit. Two astronauts will enter the LEM, which will separate from the command and service modules. The LEM will go into elliptical orbit and prepare for landing. The LEM will lift off of the Moon's surface to return to the Command and Service Modules, and most likely be left in lunar orbit. After leaving the Moon's orbit, and shortly before entering Earth's orbit, the Service Module will be ejected. The Command Module will be oriented for reentry into the Earth's atmosphere. A drogue parachute will deploy at approximately 50,000 feet, followed by the main parachute system for touchdown."

Originally a public domain film from NASA, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.

The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).

http://scitech.quickfound.net/astro/project_apollo.html

To begin with, most engineers felt that any scheme involving rendezvous was too complicated and risky; therefore they preferred "direct ascent" plans which would required at least a Saturn C-8 (with a 12 million pounds thrust 1st stage, 8 F-1 engines) or an even larger "Nova" class launch vehicle.

After President Kennedy made his "before this decade is out" speech, it gradually became obvious that the enormous rocket required to accomplish a direct ascent mission could not possibly be available in time. So the majority of engineers changed their preference to an Earth Orbit Rendezvous (EOR) plan. This would have used two or more launch vehicles (probably Saturn Vs). One would launch the spacecraft, and the other carry fuel which would be transferred to the craft in Earth orbit. Or the spacecraft and fuel might be launched in segments which would be joined together in Earth orbit

 Both direct ascent and EOR presented difficulties in spacecraft design:

1. For one vehicle to make the trip, land on the moon, return to Earth, and a portion of it reenter the Earth's atmosphere would have required a far larger spacecraft than the eventual Apollo CSM and LM combined. The fuel for the return to Earth, and the reentry capsule, would have to be carried to the lunar surface and back up to orbit. This much larger, heavier spacecraft would be far more difficult to land on the moon than a smaller, lighter one would be.

2. The shape of such a dual-purpose craft was troublesome. Pilots need to see where they are going. How could a single craft be designed which would allow the pilots to look down at the lunar surface, while allowing them to recline facing upward during ascent to Earth orbit and, later, while reentering the Earth's atmosphere? Solutions were suggested, but none were satisfactory.

Enchanted Rendezvous: John C. Houbolt and... Lunar Orbit Rendezvous..., Monograph 4 (1995) http://history.nasa.gov/monograph4.pdf

Remarks by Wernher von Braun about Mode Selection for the Lunar Landing Program, 7 June 1962 http://www.hq.nasa.gov/office/pao/History/Apollomon/apollo6.pdf