The Lunar Module was an iconic spacecraft which carried two-man crews to and from the MoonòÀÙs surface during NASAòÀÙs Apollo Program of the 1960s and òÀØ70s.ˆà Along with the Saturn 5 rocket and the Apollo Command and Service Modules (CSM), the Lunar Module is the third of the trinity of vehicles which made the moonlandings possible.
Tranquility Base:Lunar Module Eagle stands in the morning sun on the Moon in July 1969. Note Buzz Aldrin’s legs as he crawls through the hatch. Dim-witted and/or lazy conspiracy theorists claim this hatch was too small to allow a space-suited human to pass through it. Nonsense! (Image Credit:NASA)
Originally there would have been no Lunar Module.The Apollo CSMòÀÙs origins go back to the 1950s, and it was intended to be a multi-purpose vehicle for all kinds of missions in Earth and lunar orbit. President John F. KennedyòÀÙs declaration of the United States’ goal to land a manned mission on the moon by 1970 suddenly made it the focus of the project, yet it was not entirely suited to this role.
As originally conceived the entire Apollo spacecraft with a crew of three would have risen from Earth and landed on the Moon, blasting off to return home. By mid 1962 this had been studied and found to be grossly expensive to achieve, requiring the development of gargantuan booster rockets and to be so technologically complex that a landing might not be made until well into the 1970s. Instead a concept called Lunar Orbit Rendezvous was proposed (you can read a transcript of the press conference where this was announced here). This promised to be (relatively) easier and was possible with the Saturn 5 rocket which was being developed at the time.
Lunar landers compared in an early NASA artwork depicting a notional LEM (Image credit:NASA)
How would this work? An Apollo CSM would be launched (with three astronauts on board) along with a Lunar Excursion Module (LEM) on a single Saturn 5 rocket. Thrown moonward entirely by the Saturn 5, the CSM and LEM would fly together into lunar orbit; two astronauts would fly the LEM to a gentle touchdown on our satellite. On completion of their explorations the pair would take off in the two-part LEMòÀÙs Ascent Stage (leaving behind the Descent Stage with its heavy engine and landing gear) to rejoin their orbiting colleague. The three explorers would discard the LEM before returning to Earth in the CSM. In July 1962 NASA requested LEM design concepts from the US aerospace industry, then at the height of its post-WW2 powers.
Nine designs were put forward, and the winning concept came from Grumman Aerospace, a company famed for its sturdy and successful naval aircraft. In September 1962, GrummanòÀÙs engineers set about the task of building the first true spaceship.ˆà Why do I say that? All previous crewed spacecraft (and as of 2011 all subsequent spacecraft) passed through the EarthòÀÙs atmosphere during part of their flight. In contrast the LEM would spend its entire working life in the vacuum of space and would make no concessions to aerodynamics (unlike aircraft there would be no series of hundreds of test flights gradually expanding the performance envelope). Right from the start, the lander would clearly look completely unlike the sleek rockets of 1950s pop-culture. A bulbous, spindly-legged vehicle was envisaged, and many in NASA and Grumman nick-named it the òÀØBugòÀÙ.
Evolution (or in this case intelligent design) of the Lunar Module (Image credit:NASA)
The Bug began weighing 10 tonnes. It featured a spherical Ascent Stage with a docking port on top and a second facing forward (the astronauts would use this to access the MoonòÀÙs surface), while the pilot would look for a landing site through large helicopter-style bubble windows. The LEM was to have had three legs, but analysis suggested that three was not enough to guarantee a safe landing on uneven terrain. Five legs would be much better, but heavier. To save weight four legs were eventually used.
By early 1964, the LEM was recognizable as the craft that eventually flew to the Moon. The boxy Descent Stage stood on four splayed-out shock-absorbing legs ending in bowl-shaped pads, on top of it sat the curious-looking Ascent Stage. GrummanòÀÙs engineers had sweated blood to reach this point, struggling to prevent the craftòÀÙs mass ballooning to an unacceptable weight. The spherical cabin was gone, instead a cylindrical shape was used, the second docking port became a simple hatch and the large and heavy windows were replaced by small triangular panes. The astronauts even lost their seats, instead standing shoulder to shoulder as they controlled the vehicle (an arrangement which proved no inconvenience in lunar gravity).
Such was the need to make the LEM light that Grumman considered equipping the astronauts with a rope ladder or even just a length of knotted rope to climb from the hatch to the surface.However an aluminium ladder was used albeit a ladder too flimsy to support an astronautòÀÙs full weight on the EarthòÀÙs surface.ˆà The lunar landeròÀÙs shape was not the only thing to change, its name did too: it was redesignated the Lunar Module as òÀÜExcursion ModuleòÀÝ sounded too frivolous, as though it was intended for taking the astronauts on a picnic.
A general arrangement diagram of a J-series Lunar Moduleˆà carrying a Lunar Rover Vehicleˆà (Image credit:NASA)
By January 1968 when the first LM flew in space on Apollo 5 (an unmanned test flight in low Earth orbit) the design was complete. As a creature designed for an alien environment, the Bug had an alien appearance. At either side of the cylindrical cabin was a propellant tank, one for the Aerozine 50 (a mix of hydrazine and unsymmetrical dimethylhydrazine) fuel, the other for the oxidiser (nitrogen tetroxide), These two propellants had very different densities so their tanks were of differing sizes giving the Ascent Stage a lop-sided look. Behind the crew cabin was the Aft Equipment Bay, a box of environmental control systems and electronics including the craftòÀÙs Apollo Guidance Computer (the AGC, laughably primitive to contemporary eyes). Four sets of quad thrusters to maneuver the LM through the airless void were spaced evenly around the exterior. Radio communication and radar dishes were placed here and there.
The Ascent Stage sat on the legged Descent Stage, an octagonal box housing the throttleable descent rocket motor and its propellant tanks (containing a total of 8212 kg of Aerozine 50 and nitrogen tetroxide propellant) , and a modest cargo space for the equipment and instruments to be used on the Moon. (For more technical details see Grumman’s Lunar Module Quick Reference Data .)
The Apollo 9 LM Spider’s ascent stage is photographed from an unusual respective in an unusual location. This was the view from the CSM on the fifth day of theˆà Earth-orbital mission. Note the Ascent Engine nozzle. (Image credit: NASA/David Scott)
Many accounts of Apollo refer to the LM with words like òÀØflimsyòÀÙ and òÀØfragileòÀÙ but these are not wholly correct. Much of the exterior was covered in protective multi-layer insulation foil, in some locations this was taped into place. Exhaust gases from the vehicleòÀÙs engines and jets could disturb this foil and occasionally rip it to tatters, damage which is clearly visible in some images. However beneath the foil insulation was the craftòÀÙs robust pressure hull of metal skin and stringer construction. To avoid riveting or welding the skin and stringers together, Grumman precisely chemically milled the skin panels out of solid aluminium ingots so that the skin and stringers were the same piece of metal. Although its weight eventually rose to almost 15 tonnes, the LM was a fine flying machine, handling like a òÀÜnimble, responsive jet fighteròÀÝ.
James McLoughlin recently generously donated a print of Apollo 9’s LM signed by the crew to the Planetarium.This is currently displayed in our Exhibition Area. (Image credit:Tom Mason, Armagh Planetarium)
Men first flew the LM in March 1969, when Jim McDivitt, David Scott, and Rusty Schweickart successfully tested an LM (Callsign Spider) in Earth orbit during the Apollo 9 mission. Months later Apollo 10 flew to lunar orbit in May. This mission did everything short of landing: astronauts Stafford and Cernan descended to within 15.6 km (9.7 miles) of the MoonòÀÙs surface in the LM òÀØSnoopyòÀÙ and cruised over the Moon’s mountain tops. In July 1969, Armstrong and Aldrin made history by landing Eagle on the Sea of Tranquility.
Apollo 16’s LM from the rear. The Aft Equipment Bay is prominent. Just above it is the tiny angled rectangular “tab” of the sublimation plate used to “vent” heat. (Image credit: NASA)
How did the crew fly the LM? Both crewmen could control the vehicle, but oddly it was the Commander rather than the Lunar Module Pilot whoˆà actually flew it to the Moon. After undocking from the CSM, the LM fired its descent engine for several minutes to drop out of lunar orbit, descended automatically under the control of the AGC (using radar to measure altitude) until it was 500 ft or so above the surface, then the astronauts would take manual control to use the LMòÀÙs two hand controllers to adjust the programmed landing site to ensure they were going to land on a flat area and not in a boulder field or crater.
Lunar Module Descent Stage under construction.ˆà As the Descent Stage had to support the Ascent Stage not only during landing, but also during launch from Earth, it had to be quite sturdy. It was made from box structure in a cruciform shape which appeared octagonal with its thermal insulation applied. (Image credit: NASA)
LM Ascent Stage under construction Notice the cylindrical cabin crew compartment and spherical oxidiser tank without their usual skins. (Image credit:NASA)
In this image of an LM Ascent Stage under construction we can see the normally hidden aft electronics bay, the white sphere of a fuel tank for the ascent engine, the four nozzles of a set of reaction control thrusters and the dish of a communications antenna. (image credit: NASA)
To leave the LM meant sealing up the spacesuits and venting all the air from its cabin, before crawling feet first through the hatch, down the porch to the ladder. Returning required the opposite procedure. The LMòÀÙs crew enjoyed minimal human comforts with no cooking or washing facilities and only a rudimentary lavatory. Hammocks were slung across the tiny cabin to sleep in. Before taking off the crew would dump any surplus items to lighten the Ascent Stage. A little junkpile of discarded life support packs, overshoes and waste bags grew at the foot of the LMòÀÙs ladder. Dressed in their spacesuits, the astronauts fired the small, simple but powerful ascent engine under their cabin and their tiny spacecraft blasted off, using the Descent Stage as a launch pad. This take off was a modest affair compared with the earthshaking Saturn 5 launch which began the Moon missions, the Lunar Module Ascent stage didnòÀÙt need to escape the MoonòÀÙs gravity,ˆà it just had to reach a lunar orbit (orbital speed roughly 1.5 km/s) to rendezvous with the CSM. Seven minutes after ignition the astronauts would be in lunar orbit awaiting the rendezvous with the CSM. Once the LM crew transferred into the CSM, their LM Ascent stage was abandoned. All three crew returned to Earth in the Command Module.
Apollo 16’s Ascent stage looks a bit the worst for wear during its rendezvous with the CSM, see final picture (Image credit:NASA)
Developing the LM was not easy and took longer than planned but in the end GrummanòÀÙs engineering team succeeded brilliantly. The Saturn 5 and the Apollo CSM both suffered failures in their gestations, requiring extensive redesign, but the LM did not. Hoping to capitalize on the development effort, Grumman offered variants of the craft for a space programme which was expected to encompass dozens of Moon missions, including a “Shelter” version to act as a temporary base, served by freighter variants, even a wheeled version which could have landed and then trundled across the dusty moonscape. Another, in an example of ploughshares into swords, would have seen the LM, a vehicle of peaceful exploration, transformed for strange military purposes into the Covert Space Denial Module. This òÀØspace fighteròÀÙ for the USAF would have been able to use a mechanical arm to molest Soviet satellites, or even blast them to pieces with a recoilless gun. However, only one LM variant was actually built, the Extended Stay version. This was essentially a òÀØMark IIòÀÙ LM, with more fuel to prolonged hovering to allow better selection of the landing site, with more cargo space for experiments and a roving vehicle, and improved life support for a longer stay (68 hours) on the Moon. Externally identical to its predecessors, this redesigned LM was used on Apollos 15 through 17.
The National Air and Space Museum in Washington DC has a real LM (built but never used for orbital testing) parked outside its McDonald’s restaurant.ˆàFrom head-on the Ascent Stage looks oddly like a face, with the windows as squinting eyes, the hatch a gaping mouth and cheeks containing electronics and propellent tanks. Some dim-witted and/or lazy conspiracy theorists claim the astronaut mannikins at this exhibit are deliberately smaller than life-size, to make the LM appear larger than it was. Again nonsense! (Image credit:Colin Johnston, Armagh Planetarium)
Apollo 11 and the subsequent lunar landings were successes thanks to the superb design and construction of GrummanòÀÙs Bug, and the LMòÀÙs flexible design was instrumental in saving the lives of the crew of Apollo 13. Today, four complete unflown LMs are displayed in US museums, the wreckage of six Ascent Stages lie scattered across the MoonòÀÙs surface, Apollo 10òÀÙs Ascent Stage orbits the Sun, while six LM Descent Stages rest on the lunar wilderness as memorials to the first days of space exploration.
Further reading
Lunar Module Quick Reference Data
(Please note that Armagh Planetarium is not affiliated with NASA or any company which built components of the Lunar Module. We regret that we cannot help you trace, contact or research people who worked on this project.)
(Article by Colin Johnston, Science Education Director)
Apollo 16’s Descent Stage lies derelict on the Moon. It will probably outlast the Pyramids.(Image credit:NASA)
apollo 7 was a manned test flight of the CSM. Not as stated in the article.
and 6 lunar modules were impacted on the moon not 5.
Thank you very much for the corrections, I’ve fixed the article to reflect them.
Do you know the temperatures of the exteriors? Sun side and shade side of the modules? Ive been seeking that yet can’t seem to find it. I do know du pont was contracted to create a product……enter mylar. Thank you
I haven’t been able to find any measured temperature values. I would imagine the shade side would be designed for a minimum of 100K or -173 C as I see that quoted as the night time temperature on the Moon’s surface. As for the illuminated side, you see values like 390K (about 120 C) quoted for daytime temperatures on the Moon, but that is for midday under full illumination. I know that the landing sites and times were chosen so that the mission was accomplished in the lunar morning before the temperature had risen to its hottest, so the design may have been optimised for some lower temperatures than 120 C for the sunlit side.
I’ve never noticed the battered rear to Orion LEM. What happened there?
The exhaust plume from ascent engine caused some of the thermal protection panels to be pulled away from their fasteners. Some sources say you can even see this happening in the video of the take-off. Some of the other LMs received similar but not as drastic-looking damage. There’s a little bit more at Google Books.
What would be the necessary lift off and acceleration speed to escape the Moon’s gravity pull for such a heavy object as the LM?
Just to confirm, the Lunar Module Ascent stage didn’t need to escape the Moon’s gravity, that is exceed lunar escape velocity (2.4 km/s), it just had to reach a lunar orbit (orbital speed roughly 1.5 km/s) to rendezvous with the CSM. I’m taking some specifications from the book Apollo 11 Moon Landing by David J. Shayler (Ian Allen 1989), note the details of each Lunar Module Ascent stage varied (the take-off weight especially getting heavier with successive missions) so these may not be exactly right for later missions.
LM Ascent Stage mass 4.9 tonnes (including propellant, note this is a very round number so it’s probably estimated).
Ascent Stage Engine thrust 3500 lb = roughly 15600 N (this was the design spec, I assume real engines weren’t as exact as this.)
That gives an initial acceleration of 3.2 m/s/s. (Assuming full thrust is attained instantaneously).
As propellent was consumed the Ascent Stage would have accelerated faster still. By the time Apollo 11’s Eagle had reached its initial lunar orbit, it was travelling at 5537 ft/s (1.69 km/s) with respect to the Moon’s surface and had a mass of 2.7 tonnes, so 7 minutes of continuous thrust consumed 2.2 tonnes of propellant.
I hope this helps, but you may want to read a semi-technical account of the details of Lunar Orbit Rendezvous or this site where the author describes how he simulated Apollo 17’s lunar ascent.
Since I wrote my previous response, I’ve had an annoying feeling that I’d forgotten something- and I had; the Moon’s gravity! It provides a downward acceleration of roughly 1.62 m/s/s, so the initial acceleration is actually about 1.6 m/s/s.
By the way, apart from the engine’s thrust, its other important statistic is its specific impulse (essentially how much thrust per second the engine develops per kg of propellent), in the case of the LM’s engine this was about 3050 N/kg/s. This is the same as the engine’s exhaust velocity, so you can use this with the Tsiolkovsky rocket equation to calculate the final velocity of the LM.
Also see the report Apollo Lunar Descent and Ascent Trajectories.
how are they burning liquid fuel in the vacuum of space i mean i know they got to the moon by low orbit burns but the moon doesnt have an atmosphere so they cant be burning liquid fuel please help me and if possible please provide a link crediting your answer thank you.
Dear Shawn, thank you for your question. You are correct in saying a fuel needs oxygen before it can be burned. All chemical rockets burn a propellent and oxidiser together whether they operate in space or Earth’s atmosphere. Liquid propellant rocket engines bring together used a fuel and a separate oxidiser to burn together. In solid fuel rocket motors the propellant and oxidiser are bound together.
I hope this has helped you.
I still find it hard to believe they were able to cram the apollo LM and the apollo CM and SM in a single saturn V rocket with everything else needed for the missions including the ones where they started using the lunar rovers. On top of all that they had food, watter and oxygen for 8 days! Not that I’m saying the moon landings never happened. It’s just allot of stuff for one rocket to handle, not to mention the size of everything put together and launched all at once. Wouldn’t it have been easier and more plausible to send the LM and consumables (food,water, etc.) into earth orbit first then dock with it after launching the command and service module? Or did they do that for the apollo missions?
The Saturn 5 was designed to send a payload of up to 45 tons to the Moon, for Apollo 17, the total mass of fully loaded CSM and LM (including LRV, food, water oxygen) which arrived in Moon orbit was 76540 lb (38.27 tons) so that seems perfectly plausible to me.
What you are describing sounds like the Earth Orbit Rendezvous (EOR) mission profile considered in the early days of the Apollo program (and championed by von Braun). This called for the Moon mission to be launched into Earth orbit by two or more boosters. The separate vehicles would assemble together and fly off to the Moon. This was cheaper and easier than the alternative Direct Ascent profile where the entire spacecraft would have been launched from Earth and landed on the Moon. As it turned out the Lunar Orbit Rendezvous method was easier still, so that is how history turned out.
More recently, EOR was going to be used by NASA’s Project Constellation to return astronauts to the Moon. It was the only option for this project as this would have been a much larger scale expedition than any Apollo mission but the whole project was cancelled before it went anywhere.
I’ve added a link to the press conference where the LOR mission profile was announced the article, you might find it interesting.
Even with Constellation, there would have been a lander, while Orion would have been parked in Lunar orbit. Hence, the mission profile would have been “EOR/LOR”.
thats a intresting fact
Why was the LM of apollo 16 almost destroyed?
I wasn’t aware that it was almost destroyed. Can you clarify what you are asking?
Jay was probably just referring to the almost-torn-off thermal blankets.
I have always wondered about a few things regarding the landing. When I watched the live TV footage as a kid, the films showed it decending and the motor blasting away dirt and small rocks as it landed, then the live TV footage showed man taking the first step on to the moon and leaving mans foot print on the moon surface.
What puzzles me is the following: If the info I have read on the lander is correct it used 50% of its thrust capacity decendending which would put about 2500kg of thrust under the lander, which is a lot of thrust directly underneath. Now when Neil jumped off the ladder he left his foot imprint in the surface next to the ladder.
Now, I am no scientist but I would imagine that amount of force from the rocket engine would have blasted away any dust or small rocks on the surface near the lander down to bedrock, so no footprint would be possible, or if there wasn’t any bedrock and just thick deposit of moon dust then the lander would have blasted a deep crater underneath the lander untill the engine was turned off.
All pictures I have seen do not show any sort of crater under the lander, those two issues are at odds.
So I would be interested in hearing any plausable explanations. Thanks.
Dear Ed, thank you for your query. I was planning what would have been quite a long response to your question but I have discovered some other sites that essentially answer it in a lot of detail. These are Stuart Robbins’ Exposing Pseudoastronomy site, the Clavius.org site and Robert Braeunig’s site (which is lot more technical). Have a look at these, as they comprehensively answer your question.
Hi, thank you for your reply, I had a look at the links you provided and they didn’t provide me with any convincing info.
The Braeunig site, gives technical data which I am not qualified to understand or refute, they state that “This isn’t much data to work with, but we can fill in the blanks with educated guesses”, however they mentioned that the gas velocity was in the order of a minimum of 1000m/s to 1700m/s, which is extremely fast coupled with the supposedly 1000kg of thrust in the decent would to my way of thinking blast away any of the dust on the surface. I know what effect my ordinary leaf extractor does on sand and that only has a velocity of about 60-80m/s and from a distance of 1-2mt. and it also does not produce the amount of force that the luna landing rocket produces to be capable of slowing down and suspending a mass of several tonnes off the surface on the descent.
The surface of the moon was described as having small rocks and powdery fine dust and no moisture.
The last paragraph of the Clavius site is “The exhaust plume is simply not powerful enough to dig holes in the tightly-packed regolith”. So this would imply that the lunar module is now sitting on bedrock of some form, ie; no dust! Hence there would not be any dust in the immediate area to leave the foot prints behind. Being in a vacuum and 1/6th earth gravity the blast area would be significant with the powerful hot and extremely fast gasses being unconstrained by any atmosphere, and being effectively squeezed out between the rockets focused blast of about 1m and the lunar surface.
Comparing the rocket engine decent to the Harrier’s jet landings is also not evidence as I have yet to see a video or image of one of those landing on a dusty moistureless airless surface as described on the moon. If one did land on the surface of, lets say a dry desert sandy surface I would imagine that there would be quite deep craters beneath the engine exhausts, but again those engines are bigger and stronger than the Lunar modules had, so no comparisons can be made.
So anyway, without turning this tread in to one of those long winded conspiracy theory posts and going on and on, picking out inconsistancies here and there. I guess none of us Joe public will ever know one way or another as all this “evidenceor proof” is based on theory and not on actual fact.
But as a passing thought, all this info is based on the visible effects of the images supplied and the best guess and technical examination of many may or may not fit the visible effect of the images.
However and most importantly, with the risk of sounding like a conspiracy theorist…. What if the images aren’t actually taken on the moon? in which case the info and technical details may fit the pics but doesn’t actually prove that they were taken on the moon! Just a thought.
To me, I still remain unconvinced one way or the other, it just looked odd, always had and 4+ decades later still does.
Cheers
But what about Stuart Robbin’s Exposing Pseudoastronomy site?
Ed,
Consider there is quite a difference between “blow away some dust” and “blow away all the dust”.
Next, the ngine was throttled down to far less than 50%. Upon touchdown, the LM’s mass was about 8 tons. Given the 1/6 lunar gravity, this would be equivalent to a weight of some 3,000 lbf when the LM was hovering.
Also, consider that there is no ambient atmospheric pressure that would compress the exhaust plume into a narrow column of thrust. Rather, the exhaus gases would expand into all directions immediately after leavinig the engine bell.
Comng back to my first point: the regolith is not just a few inches thick, and the material is very adhesive. I think the braeunig paper provides quite a good explanation, based on the well-established laws of physics.
Thx,
Roland
How was the little the lunar module able to find the Command Module in orbit with its little radar and maneuver into position for rendezvous with Command Module with so little fuel?
Did they have some kind of AWACS assistance? Their radar is so tiny.
Hi, thanks for the question. Like many space endeavours the basic concept of this is simple but doing it is pretty complicated. It’s exactly how any spacecraft is launched from a surface to rendezvous with another in orbit, just like sending spacecraft to the ISS is done today.
The orbit of the CSM was known very precisely, so at any given time its position in space could be accurately predicted. The launch position of the LM on the Moon’s surface was known to an acceptable degree of accuracy. By launching at the right time the LM could be put into a similar orbit to the CSM and be maneuvered to an eventual docking.
The LM’s rendezvous radar was acceptable for what it had to do (you can read the technical details here). The dish isn’t as small as you may think; it was 24 in wide which is the same diameter as the dish on early F-4 Phantoms (developed a few years earlier).
I hope this has helped.
…and the techniques for achieving rendezvous in orbit had been evaluated in 1965/66 during the Gemini program (Gemini 7/6 in December 1965, and Gemini 8 thru 12 between MArch and November, 1966).
Thx,
Roland
The mechanical instability of the lunar module would have an intact lunar landing impossible!
Every person on our planet has probably already seen a failed rocket launch, when the rocket has already picked up a few meters from the launch pad and then the engines fail and do not produce more power. As a result, the rocket moves the physical laws of gravity accordingly again in the direction of the launch platform and then tilts due to the mechanical instability simply because the center of gravity has changed dramatically. This would also be the fate of the lunar module of Apollo 11 was because shortly before landing an absolute instability of the ferry had passed! Because the ascending stage would have very roughly to the ground just before landing on the moon for about 5 t and the descending stage would due to the fuel consumption of only 8 t only about 2 tonnes of empty weight had. As the focus of the lander must have lain precisely just before the landing of the ferry on the moon at xm, the torques would like 2.5: 1 to 3: 1 behaved. For an absolutely unstable mechanical system would be active! Even the smallest vibration, such as vibration through the engine or pressure fluctuations in the effluent gases in the nozzle of the engine would have the moon position ferry can easily tip over! A moon landing would indeed be “successful”, but a return from the moon would have been so impossible. But 11 have fortunately survived the imaginary adventures all actors of Apollo, it can be concluded razor-sharp that no moon landing took place.
The solution of the problem is that the focus of a lander simply must be at the level of the nozzle of the engine, such as the Chinese realize this in December 2013, and practiced.
P. S. Incidentally, the author was skeptical thoughts on the instability of the lunar module landing on the moon more than 45 years ago spontaneously for about 1 s had cherished!
Siegfried Marquardt, Kingswells, the 30/10/2014
Dear Siegfried, I think you are grossly underestimating the abilities of engineers. Do you also disbelieve in vertical take off and landing aircraft? The problems seem very similar.
How due you think so many rockets get to put things like the ISS and satellites on a big unstable rocket, or are they all faked. They use gyros linked to servo driven gimbals on the engines to “balence on the thrust”. You don’t seem to have any relevant engineering knowlege, you don’t even understand that an object that wieghs 8tons on earth is 1/6 the the weight on the moon. It’s a shame that the Japanes took pictures of one of the landing sites, I makes you look so silly.
Phill
P.S. What dose “the torques would like 2.5: 1 to 3: 1 behaved” related to a rocket engine mean in any language?
(If you wish this comment to be published please 1) make it more concise and 2) re-submit it in English, thanks- ADMIN)
Summary of mathematical-physical refutation of Apollo 11 …
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…Siegfried Marquardt, Kingswells, in July 2014
(Dear Mr Marquardt, I am not permitting this content for multiple reasons. At over 1000 words it is far too long (I requested that you edit it but you did not). I have discovered that you have have already distributed this material on numerous other websites so it appears that you are not here to discuss our article but to distribute your essay. Surely you can host this material on a website of your own? -ADMIN)
That hunk of junk couldn’t take out the garbage let alone go to the moon. This has to be one of the biggest jokes in the history of humans.
Hi Fluffy, thanks for your comments. It might be very interesting if you could explain why you think that.
The distance between earth and ISS is ~ 350-400 miles.
Time to reach ISS from earth 6 hours.
The distance between earth and moon ~ 240,000 miles.
Time to reach moon from earth ~ 8 hours.
How is it possible…considering the orbital trajectory which is much longer.
about 50 years ago we were able to decide where to land in moon.. with out any studies. and very little computing power.
Now we are still looking for water in moon by explosion and infrared spectoscopy?
50 years ago we were able to have a live feed of lunar landing from a distance of 250,000 miles with great clarity.
We are still having clarity problem when we transmit satelite signals and live war images from afganistan.
to get an image from mars robot it takes few hours. mars is only 249 million miles away.
It is hard for me to believe that saturn 5 rocket was able to send 45 tons to 250000 miles.
Mars rover weigh merely 80 KG.
but we were able to send 2 man and 15000kg(15 tons) of weight to moon 50 years ago. And a craft was able to lift off ang go about 3 times speed of sound perfectly.
We are still struggling to have 3 mach misile??
Answer with some facts and numbers…please
Dear Biju, thanks for your comments. Sadly I think you may have to revisit some of your research.
I donòÀÙt understand this. What took 8 hours to move between the Earth and Moon? Apollo missions took more than three days. See How Long Does it Take to get to the Moon?
Moon landing sites were selected after extensive Earth-based mapping and by the data returned by three separate series of robotic probes. These were the Ranger, Lunar Orbiter and Surveyor missions. There is an interesting essay on this hosted by the BBC. The Apollo missions took as much computing power as was needed. Remember this was before the hugely memory-hungry operating systems of today and there was no need for graphics. There is a feature on ApolloòÀÙs computers at Computer Weekly that might interest you.
I donòÀÙt understand your point, but yes. Theory developed since the Apollo missions suggests ice could exist at the MoonòÀÙs poles, so missions have been carried out to confirm this.
Again I donòÀÙt see your point, modern TV reports by satellite I would guess are superior in resolution to live Apollo broadcasts, perhaps you should see the book Live TV from the Moon by Dwight Steven-Boniecki which examines how the Apollo TV broadcasts were done.
Again, I do not know what you are asking here.
Sorry you feel that way. May I ask why this seems hard for you to believe?
Again there is a research failure here on your part. I do not know why you think Mach 3 is so important but missiles have regularly exceeded this speed since the 1940s ( the A4 or V-2 could exceed Mach 4 and that was in 1943).
I hope this has helped you.
Hi Biju
Has it ever passed your mind that some basic undertanding of science and the solar system might be helpfull when making your silly comments.
Mars is about 56 million miles away at it’s nearest but can be over 400 million miles away as it is in a different orbit.
Have a look at this PDF about the development of the Apollo’s (and other engines): These are real engines that now puting all sorts of stuff up in space (or do you think phones, weather pics and GPS are fake too)?
http://history.nasa.gov/monograph45.pdf
Why don’t you spend a little time looking into basic engineering, science or the primary school astronomy that seems to have passed you by?
Phill
Apollo 11 moved at the speed of 26,640 km/h. But it took the spacecraft to reach the Moon 3 days. At that speed it should have reached the Moon in about 14 hours. Eric Poland, Europe / California
Dear Eric, thank you for your comment. Unfortunately I must just point out that the Apollo 11 mission left Earth orbit not at 26 640 km/h as you stated but at 24 545mph (39 500 km/h) – just a little less than the escape velocity of Earth. You are correct in saying that if the spacecraft moved the whole journey at this speed in a straight line the journey time would be well under three days (by the way, this would only work if the Moon was stationary with respect to the Earth). The solution is that the spacecraft did not maintain this speed.
After a final boost from the Saturn 5’s upper stage, the spacecraft coasted to the Moon, experiencing EarthòÀÙs gravitational pull as it climbed higher. The spacecraftòÀÙs speed was progressively slowed until the MoonòÀÙs gravity became dominant, the spacecraftòÀØs speed was down to about 2040mph (3280 km/hr) relative to the Earth by this point.
Note also the spacecraft did not fly in a straight line but a curve (it was still in Earth orbit until it entered lunar orbit).
I hope this has helped you.
Dear Admin. I hope this is not an abbreviation for ” Aministration ”. I expected the exact answers from you as you have them stated. Yes, agents such as back-pull of Earth’s gravity on the capsule would be the major slow down of the spacecraft. Also, the Moon’s orbit constatly changing the position of it in the heavens, therefore navigating in such a way as not to crash onto the Moon. I want you to know that I watched the first lunar landing on a black and white TV in Poland when I was a small boy. Besides the transmission of the lunar TV picture was in black and white anyway. Physics were my main interest in Poland before I immigrated to the US in 1974. That was five years after the first step on the Moon and 2 years after all Apollo programs were ended.
In the US I was still interested in physics and after entering US Army and separating from it 3 years later I began studying physics which was very hard but I managed to get something out ot it even though I was rather a computer technician. I was never interested in computers. Till today all my interests in life are glittered with physics and whatever the subject I pick up I relate to physics. I let you know that I am not an expert in physiscs but Newtonian physics give no problems. I am not one of those theorists who claim that there was no landing on the Moon. Moon landind hoax would rather pertain to one landing, but why would one want to fake six of them? That would rather be nonsensical. Yet, there are plenty of discepancies in all the landings on the Moon.
I have been interested in the hoax for years. But my it was rather skin deep until one time I visited an acquaintance of mine in Burbank, Calfornia in 1991. We had a party there. And as usual we had quite a few drinks. Then I told my friend that I was a short wave buff a long time ago and now I am an electronics techician and that somehow electonics don’t want to leave alone. Then he walked me into a room with all kinds of electronic stuff along with real to real tape recorder, HF, VHF, UHF radios plus some radio working in microwaves. He told me that he had proof that lunar landings were fake. He set up a real to real and he said that he recorded conversations that supposedly came from the Moon and he said that when he directed his directional antenna he could perfectly zoom on Hollywood and picked up conversations on the VHF radios between studiomen who were busy in staging the whole landing in some studio below his house which was located on a pretty high hill in Burbank. I remember only one sentence from that tape that he played for me because we were both drunk and I really did not pay attention to him as well as to the recordings because at that time I hardly heard about any Moon landing hoax. The sentence rang as follows more or less: ” get that ladder closer because I can’t see him in he camera. ” My friend told me that he heard Armstrong’s voice in the background in VHF radios and that Armstrong was on the Earth because there had been no time delay between an astronaut and alleged mission control. Whether that was genuine I don’t know. But I wanted to get back to the girls and this never came back to me until I was beginning to get interested in Moon Hoax.
You have to admit that some things in videos and all kinds of data brought from the Moon are just a bit shaky. I will give you an example which so far I never found being brought up in a supposedly real film of the last mission to the Moon; Apollo 17. There is a guy claiming that Gene Cernan and Schmitt complained that because of the grip of their fingers in spacesuits. Because of the pressure in the spacesuit the gloves would become rigid thus unabling correct grip on things. To overcome that Cernan and Schmitt had to fight that by straining their fingers inside the gloves which caused sores, abrasions and scratches on knuckels all the way to loss of skin on them and raw small wounds. That’s what Cernan claimed in his report. Watch this video :
This is supposedly the real entry of Cernan from LM into Command Module after docking. You have to be quick to catch Cernan’s right hand ( I believe ) at the frame of 34 minutes and 15 seconds. The hand moves very quickly and I managed to stop that on the dime. Cernan’s hand does not reveal any damage to the knuckels’ skin as he said, raw to the bone. We would see red stain from blood or other sacratches. I see no such thing.
That’s it for now. And thank you for your answers.
Eric Poland, EU / California
Dear Eric,
òÀÜAdminòÀÝ is short for Administrator.
So why did you ask then? You appeared to be asking a genuine question but now I am afraid that I am doubting your sincerity.
Opinions are not facts.
ThatòÀÙs a fascinating anecdote. Have you any evidence that this is correct?
No, that is not true.
Astronauts to this day complain of trauma to their fingers caused by spacesuit gloves, but I would suspect òÀÜraw to the boneòÀÝ is not meant as a literal description.
Dear Admin. I need to correct my English in my last post to you. In the beginning I called you ” Aministration. ” It should be Administration. ” Real to real ” tape rcoder should be reel to reel, of course.
But to continue a bit on the landings on the Moon I have a copy of a couple of blue prints of the whole LEM. The ascend stage was attached to the descend stage which always was left after the ascebd stage lifted off the Moon. It is peculiar how much slmall of a space the whole LEM represented and the ascend engine fit in so perfectly almost not noticed. Also, the blue prints do not show any clamps or some hooks that would keep the descend and ascend stages together. Because in order to separate the two stages one from another there just had to be some attaching devices to both of them to keep them together in space.
So long for now.
Eric
Poland, EU / California
Dear Eric, the LM Ascent and Descent Stages were connected at four points which were severed by small explosive charges. There is a summary of this in the document Lunar Module Quick Reference Data (link). The Ascent Engine was, as I am sure you understand, designed to be as small as feasible and not to occupy a significant portion of the habitable volume.
Content removed.
Please stop trying to post this essay on our site, publish it yourself! – ADMIN
Dear Admin ! I wonder that you question my sincerity. But as free persons as you and I are, you have a right to such things. I just feel bad that I may have offended you. But be sure I had no single thought of it, nor any thought of it whatsoever. Maybe the fact that I expected something back that would align with some-one elseòÀÙs information comes from my innate need for confirmation. But I also love great brainsòÀÙ anecdotes such as one of EinsteinòÀÙs that opinions not submitted to scrutiny is a manifestation to ignorance.
I looked into òÀØòÀÙ Lunar Module Quick Reference Data òÀØòÀÙ. Thank you very much. The blue print of LM I acquired at a book store in Poland does not show the bolts nor does it show the fifth explosive charge that would sever the umbilical wires from two stages. That, too, must have been done before ascending. What it does not show either is how the ascending engine is mounted.
Naturally after severing the cables from each of the stages there had to be alternate ways of controlling the ascending engine for the cables and any other circuits would be useless after cutting all of connections to the descending stage.
Now, I want to get to what Yuri Gagarin said when he was blown into space and what Collins said at the Press Conference after coming back to Earth. The Apollo astronauts were able to see stars using optical instruments whereas Gagarin uttered words: òÀØòÀÙ stars look astonishingly brilliant òÀØòÀÙ. Collins said that he did not recall seeing any.
And Gagarin was not the first man in space. Russians lost three other cosmonauts. Two of them are supposedly lost somewhere in space.
What is also peculiar how Neil and Buzz left LEM to step on the Moon. They had to decompress the LEM thus leaving gases on the Moon. I have oxygen in mind along with some carbon dioxide from their lungs. But coming back into LEM they had to compress the LEM. So, along the burned hypergolic fuel the MoonòÀÙs surface got a dose of air decompressed from LEM; it became a part of the Moon or dispersed into space as the Moon has too low of gravity in order to hold down atmosphere. But yet some sources claim that the Moon has very diluted atmosphere. And that may account for the flag moving towards the astronaut while an astronaut walks by the flag thus from the BernoulliòÀÙs principle we know that that is the case as the walking of the astronaut creates a low pressure between the flag and the person walking by.
DonòÀÙt want to write too much, so IòÀÙll stop now.
Sincerely
Eric
Poland EU / California
Dear Eric, I am afraid your anecdote claiming the Apollo astronauts needing optical instruments to see stars is based on selective reporting of what was really said. At the press conference Armstrong discussed photography of the Sun’s corona by the three astronauts from the CSM on the outward journey. Patrick Moore, the British TV astronomer asked:
“I have two brief questions that I would like to ask, if I may. When you were carrying out that incredible Moon walk, did you find that the surface was equally firm everywhere or were there harder and softer spots that you could detect? And secondly, when you looked up at the sky, could you actually see the stars in the solar corona in spite of the glare?” (My emphasis)
Aldrin responded to the first part. Then Armstrong responded to the second part.
“We were never able to see stars from the lunar surface or on the daylight side of the Moon by eye without looking through the optics . I don’t recall during the period of time that we were photographing the solar corona what stars we could see.”
“Optics” refers to the LM’s navigation telescope. Stars cannot be see from daylight side of any planet in the inner Solar System as the Sun and reflected glare from surfaces are far too bright.
There is no truth whatsoever in the claim that Gagarin was preceded by “lost cosmonauts”.
The Moon’s atmosphere is to all intends non-existent, the vented gases from the spacecraft probably did locally cause a brief increase in the atmospheric density around the landing site but not enough to cause flag movement.
Hi Admin,
Thanks for the great article. I also found your patient replies to the above comments to be very helpful.
I’ve never understood the draw of the conspiracies revolving around the Apollo missions. I’m really not sure what is to be gained by proving they never happened.
If you haven’t had a chance to see the film Interstellar, I highly recommend it. Despite some science fiction elements, it does a great job celebrating space exploration. There is a great scene where Matthew McConaughey’s character encounters a school teacher that believes the Apollo conspiracy theories. His reaction is golden!
Thanks again,
Jon
Why do you go to so much trouble to convince crackpots? What difference does it make if some folk don’t believe? They might pass their doubts to their children but once in school they will hear differently. Space travel, like the proverbial caravan, moves on despite their barking.
Hi Damocles, we are an educational institution so we are obliged to challenge and correct factual errors especially if we are asked questions about them.
Apollo 11 and N is always refuted!
In a conventional calculation of the fuel balance, assuming an effective exhaust velocity of 2600 m / s, a fuel shortcoming of over 160 t for the Apollo mission would. Its commitment to an effective exhaust velocity calculations of 3700 m / s; ‘ve never been reached in 1969 and currently can not be achieved, it would fuel a deficit of over 70 t come. Because: For the confluence with the lunar orbit, the CSM would be decelerated with trailed LM of 2.4 km / s (lunar escape velocity) on the Moon’s orbital speed of 1.7 km / s. These would be a fuel quantity of [(2.72 high (0.7: 3.7) -1] * 45.3 = t 9.5 t have been necessary for the moon landing, a propellant mass of [(2,72 would highly. (1.7: 3.7) -1] * 15 t = 8.8 t The start of the moon would have [(2.72 high (1.7. 3.7) -1] * 4.7 = t 2.7 t required and made the escape from the gravitational pull of the moon would have [(2.72 high (0.7: 3.7) -1]. * 30 t = 6.3 t rocket fuel requires for the confluence with the. Earth’s orbit would be [(2.72 high (3.3: 3.7) -1] * 30 t = 44 t of fuel have been necessary sum up thus resulting 71.3 t Now there stood only about 15 tons of rocket fuel to.. available (4 t CSM and LM 11 t). Thus, Apollo 11 and N were refuted forever.
Dear Mr Marquardt, thank you for your comment. I am afraid there is much here to suggest that your knowledge of this subject is not perhaps as accurate or complete as you believe and this invalidates your conclusion.
You claim a rocket exhaust velocity of 3700m/s is not currently achievable. Yet LH2/LOX rocket engines of exhaust velocity of about 3800m/s have been available and used in rockets and missiles for decades!
You say
Unfortunately this is incomprehensible, can you explain what you think this means and what the quantities involved are?
Using erroneous facts and pseudo-mathematics does nothing to prove your point!
You may be doing the wrong drugs. Stop making it up. And please don’t just copy and past the same numbers with no units over and again, It’s not going to impress.
“These would be a fuel quantity of [(2.72 high (0.7: 3.7) -1] * 45.3 = t 9.5 t have been necessary for the moon landing, a propellant mass of [(2,72 would highly. (1.7: 3.7) -1] * 15 t = 8.8 t The start of the moon would have [(2.72 high (1.7. 3.7) -1] * 4.7 = t 2.7 t required”
Not even close to anything!
Why not try Maths and Science. You are not worth talking to again.
Phill.
To:
Siegfried Marquardt
Oh I had to mention.
YOU CAN’T COUNT YOUR BRACKETS.
Go away please.
(Final line removed- Please keep it civil- ADMIN)
I found your article interesting, and your responses to some of the comments entertaining and enlightening. I found this thread looking for info on how the apollo slowed down to land on the moon, and you described it above…………i appreciate that…..and reading your responses to the moon landing hoax guys is hilarious:)….i was tempted to post some wacky stuff for fun:)…good job, your responses were educational.
Dear Billy, thanks, I’m glad you found this article helpful.
TEXT REMOVED- ADMIN
(Dear Mr Marquardt, this is the final time I am going to respond to you. As you have been told numerous times before, we are not going to publish your essay because of its excessive length.
I have taken some time to read your essay and found it to be full of errors and misconceptions. I would offer the suggestion that before you offer it for publication elsewhere that you carefully review and check the text for factual and scientific and technical accuracy against numerous reliable sources. ADMIN)
Reading some of the comments,its suggest to me,that some people are still are questioning the 6 Moon landing’s.I suggest doing your own fact seeking,from those people directly involved in the Moon program and sites like this.Don’t expect factual answer’s from conspiracy sites.I visited one site,they didn’t even know how the lunar lander transversed from lunar orbit to the Moon,claiming the reaction control thrusters was its only propulsion source and could not of gotten the lander to the Moons surface,they seemed to have missed the main engine.
Admin:
Good site and information. Very nice handling of hoaxers. Civil, yet firm.
I doubt you would be extended the same courtesy.
Again, thank you for your time and expertise.
1. In the photo of the LM at the start of this article, how is it that despite the photograph having been taken directly into the sun, that the details of the LM and in particular the words United States can still be read and that the shadow side is so well lit? Professional photographers and those familiar with the Hasselblad cameras used are saying that the latter is impossible without fill-in studio lighting.
2. I believe I am right in saying that there is no footage of any LM ever having been landed successfully on a test flight and obviously not in one sixth of the earth’s gravity, so how did The Eagle land first time perfectly on the lunar surface and without any evidence of dust disruption below the central thruster that must have been actively firing on landing or dust on the lander feet? This photo appears to be a studio shot where the LM has simply been lowered down by a crane.
3. How hot was it allegedly in the LM when the Astronauts got back inside since it was in direct sunlight? Is there any recording of Astronauts mentioning being uncomfortably hot or cold as with such untried thermal systems in such extremes of temperature the chances of getting the thermal balance right first time were very slim.
Thankyou.
Dear Phil, thanks for your questions. I’ll try to answer them as concisely as I can.
1. There was a kind of fill-in lighting from the Moon’s surface. When sunlight falls on the lunar surface it bounces off it in all directions. Some of it goes back out into space, but some is scattered by the lunar surface at lower angles can illuminate objects in shadow.
2. As it was impossible to simulate lunar gravity on Earth, the LM could not be tested on Earth, so every flight of the Lunar Module was essentially a test flight. I could argue that the six missions that landed on the Moon were successful test landings! As to your “dust on the feet” query, a rockets or jet powered vehicle descending in a dusty landscape on Earth will blow up billowing clouds of dust particles which slowly descend, buoyed up by air resistance. However you are aware that the Moon has no atmosphere, and that means dust behaves differently. Dust particle are blown up by rocket thrust on the Moon, but fall straight to the ground again. The descending LM was not surrounded by a billowing dust cloud. Also the Descent Engine was throttled back in the final stages of landing and in fact was shut down 5ft above the surface. The chances of dust gathering on the pads was very low. I’m happy to confirm the picture was not taken in studio but on the Moon!
3. I’m not sure what the temperature was on board the LM when the astronauts returned to it. I know the the atmosphere and temperature in the LM’s cabin were maintained inside acceptable levels by the Environmental Control Subsystem (which you can read about at this link). I do know on one mission (possibly Apollo 11) the LM crews reported the cabin was uncomfortably cool for sleeping in but this was not noticeable when they were active. I would remind you that the LM’s systems were designed based on the experience gained on early projects, especially Gemini, and were tested before Apollo 11 both on the ground and in space during the Apollo 9 and 10 missions so the engineers were not working in the dark as much as your question implies.
I hope I have helped you.
First of all, bless you for having the patience to try and work through these questions. I’d like to add a little to your answers if I may be so bold.
1. Light to fill in the shadows came from several places, the moon’s surface as you mentioned, but also the Earth, and the Photographer. The Earth shines light onto the moon just like the moon does to Earth, only about 40X brighter because it’s bigger and reflects more light per unit area. And the photographer, or more specifically, his bright white space suit. In any photo where the camera is pointed toward the sun, the astronaut taking the photo is acting like a photographer’s reflector.
2. NASA built 5 types of simulators to allow the astronauts to practice flying the LM in 1/6 gravity. It’s certainly true no actual LM landed in 1/6 gravity, but actual LM’s flew on Apollo 9 spent more than 100 hours flying, and developing data that was used to refine the simulations. Apollo 10 added 9 hours in lunar orbit. The LLRV, a sort of jet powered spider looking thing, is the most famous but there were 4 others. Some of the simulators are seen in this document: http://www.nasa.gov/centers/langley/news/factsheets/Apollo.html It’ safe to say the LM pilots flew with 100s of hours of simulations before they landed on the moon.
3. The LM was insulated, and had an active cooling system, detailed here: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720013195.pdf And don’t forget the NASA had the data from the 5 Surveyer missions that landed on the moon prior to Apollo.
Dear Brad, thank you, that’s both interesting and helpful!
Fascinating article, I love anything space-related and have always had a soft spot for the lunar module, since seeing Apollo 13 and how it was used as a lifeboat. I never ceased to be amazed by the folks at Grumman who designed such a good spacecraft.
I’m glad I’m not the only one to think that the LM has a face – I see faces in inanimate objects constantly! I do hope I can travel to the USA and visit the space museum in future. I want to study aeronautics as a career.
Lena, age 14
P†ärnu, Estonia
If you haven’t seen the “From the Earth to the Moon” mini-series, I highly recommend it. There’s one episode that dealt with just the development of the lunar module that is my favorite. Here’s a brief clip:
https://www.youtube.com/watch?v=DLQeqMaHVYs
Interested me enough to get Tom Kelly’s book “Moon Lander” which I also highly recommend. Just amazing all the problems they had to overcome designing the first true spacecraft.
Hi
I’m a “it did not happen man” but i want to believe.
Just one Q so I can get my facts correct, thanks in advance. Q. Where was the heat-sync / radiator for life-support/cooling located? Thanks, not a trick question just location if known.
Hi, thanks for your question. The “plumbing” for the Lunar Module’s active thermal control system was located in the Aft Equipment Bay (the “box” at the rear of the Ascent stage) and the porous plate evaporator which I guess could be described as a radiator is a small “tab” above the Aft Equipment Bay. It is very hard to spot in photos of the LM, but I’ll add one the article.
I was wondering what kinda fuel they used to blast off since there is no air on the moon.
Dear Kathy, thanks for your question. The rocket motor used to blast off from the Moon, the Lunar Module’s Ascent Propulsion System was a typical liquid propellant rocket engine, so it used a fuel (Aerozine 50: a mix of hydrazine and unsymmetrical dimethylhydrazine) and an oxidiser (nitrogen tetroxide). I will add this information to the article.
I hope this helped you.
What was the velocity of Columbia and that of the module when their rendez-vous took place? It seems really impressive that it worked pretty fine the 6 times, with the module ascending and managing to successfully get reunited to the Columbia.
Thanks in advance for the help in understanding it.
Dear John, in lunar orbit the CSM and LM were both traveling at about 1.5km/s (5400km/h or 3355mph) but their closing speed relative to each other during docking was “a few tenths of a foot per second” (Source at this link). The absolute speeds of the vehicles does not have any effect on how difficult the docking process is. Do note that docking spacecraft together happens all the time in Earth orbit (at much higher speeds, say 7.66km/s for the ISS) and are successful almost every time.
By the way, Columbia was the CSM for Apollo 11 only, different missions had individual names for their CSMs.
Thanks a lot for answering!
Really great article. My 6-yr old son is fascinated by retro spacecraft, in particular the lunar module. Can anyone recommend any good books?
Dear David, thank you, I am glad you enjoyed our article. Two good space books for children your son’s age are:
My Very First Space Book by Emily Bone (published by Usbourne)
See Inside Space by Katie Daynes (also published by Usbourne)
Anyone else have suggestions?
@David D. Hand your son might enjoy the short story I published recently about the lunar module “Eagle” which is free to download (PDF format): http://www.lulu.com/shop/nikki-bolton/when-eagle-landed/ebook/product-22331701.html
Eagle is personified in this and the story follows the Moon landing from his point of view. I am a huge fan of Apollo missions and wrote this story just for fun. I was quite surprised that nobody else out there had ever drawn the LM with a face!
Thanks, very interesting article! I remember watching the moon landings when I was 11 years old and these things still fascinate me four decades later. I’ve visited KSC twice, once in May1981 (weeks afer the first shuttle flight) and again in 2008. I bought the “From the Earth to the Moon” series and thoroughly enjoyed it.
To give a few of my own answers to a couple of the previous queries:
1- Hard time believing that the Saturn 5 could carry 45 tons to the moon? Go walk under the displayed Saturn V rocket at KSC and marvel at the size of that sucker! The five massive F-1 engines on the first stage are a sight you’ll never forget! they’re also the first thing you see when walk in. The real LM displayed is also very interesting.
2- Think the whole thing was faked? Please explain over 830 lbs of moon rocks that have been examined by thousands of geologists who have never doubted their origin. Add to that the samples obtained by the USSR from their three Luna sample return missions (many people don’t know about these) whose properties were very similar to the Apollo mission rocks. The USSR would have been the first to decry anything fake. Enough said…
I have a question I was hoping that you could help me answer, or show me the calculations needed to derive the answer.
Assuming for the purpose of this question that you are not concerned about acheving earth orbit, but instead a destructive reentry perpendicular to the surface of the earth.
If you were to launch a payload from the moon acheiving a Lunar escape velocity towards the earth aiming to have minimal velocity passing past the earth moon L1 point.
How fast would the object be accelerated to from the freefall from L1 to atmospheric rentry at an altitude of approximately 100km?
Thanks for the help
Dear Sean, thank you for a fascinating question. Are you writing a science fiction novel perhaps?
Basically you are asking what vertically downward speed (with respect to the centre of the Earth) an object (of mass m) would have if it was “dropped” from the L1 point.
When the object is r metres from the centre of the Earth, it will have potential energy (again with respect to the centre of the Earth) equal to GMm/r (G is the universal gravitational constant, M the mass of the Earth). Let’s say at L1 r=L
Once the object falls towards the centre of the Earth it will have kinetic energy 1/2 mv*v (where v is its speed towards the centre of the Earth . Since energy is conserved, the difference between potential energy at altitude r and altitude L must equal the kinetic energy at altitude r, so 1/2 mv*v=GMm(1/r-1/L). Putting numbers into this (assuming L=1.5 million km, r=6500 km), I get v=11.06 km/s (which is just a little under the Earth’s escape velocity).
Ok, so one of the reasons this thought experiment came up was a way to make the story work where I wouldn’t have to try to do the orbital dynamics calculations to make the science somewhat realistic (lunar kinetic energy weapons platform launching lunar boulders).
Based on my understanding of the calculations, regardless of the distance from which an object is “dropped” it will never be accelerated to a speed beyond the escape velocity of the body itself.
So for the reference frame of the Earth-Sun L1 at 1.5 million km the speed is 11.06km/s
From the Earth-Moon L1 assuming average orbit of 384400km and L1 of 58030km from moon center gives a distance of 326370 km from earth center. Using these numbers I get 10.96 km/s
However being in a “straight” line with the moon means that the acceleration towards the earth will be lessened by the moons gravitational pull… so calculating these numbers from moons reference and subtracting them from the pull of earth… oh wait, it also gives 10.96km/s.
Thank you for showing me how to do the basic calculations to make the math accurate and the science somewhat plausible ÅßØÉ
How much fuel was needed to send this thing to the moon and get it back to earth? Something about this smells fishy….
Dear James, to get the entire Apollo spacecraft (Command/Service Module and Lunar Module) to orbit the Moon took a three stage Saturn 5 launch vehicle. Adding up the masses of propellant for the three stages (found at this link) I get 2708 tonnes of propellant.
The Lunar Module carried 8212 kg of propellant to land on the Moon while its Ascent Stage carried 2639 kg of propellant to take it back into lunar orbit. I assume you understand that the Lunar Module did not return to Earth!
Nothing “fishy” here just great and well-resourced engineering!
I hope this has helped you.
“Something about this smells fishyòÀæ.”
Correct! That’s caused by Aerozine 50, the fuel used by the Lunar Module. It has a characteristic ammoniacal (“fishy”) odor.
Was the applo 11 landing true or a big hoax.
Dear Christian, did you read the article?
yes
Dear Christian, that’s good. I hope that helps you.
I suggest all the naysayers on this site read Gene Kranz book, “Failure is not an option.”
As most people know, Kranz was the flight director for the successful Apollo 11 moon landing. There could not have been a more dedicated and honest group of people than those associated with the NASA space program. I personally knew two of the astronauts, Gus Grissom and Frank Borman. To suggest that either one of these fine people would have been party to a hoax is vile and repugnant. Apparently a cottage industry has mushroomed around the conspiracy theories dealing with the moon landings. Money must be involved.
I still don’t get it ..how could the LM attach itself after taking off from the moon surface to the Orbiting module which is moving at high speed.
In 1968 did they have such a precision technology to dock on two vehicles moving at such high speeds?
Please explain how?
Dear Surya, thank you for your comment. The same question has been asked before so I am adapting my previous answers.
Launching the LM’s Ascent stage and rendezvousing and docking with the CSM was done exactly how any spacecraft is launched from a surface to rendezvous with another in orbit, just like sending spacecraft to the ISS is done today.
The orbit of the CSM was known very precisely, so at any given time its position in space could be accurately predicted. The launch position of the LM on the MoonòÀÙs surface was known to an acceptable degree of accuracy. By launching at the right time the LM could be put into a similar orbit to the CSM and be maneuvered to an eventual docking.
In lunar orbit the CSM and LM were both traveling at about 1.5km/s (5400km/h or 3355mph) but their closing speed relative to each other during docking was òÀÜa few tenths of a foot per secondòÀÝ (Source at this link). The absolute speeds of the vehicles does not have any effect on how difficult the docking process is. Do note that docking spacecraft together happens all the time in Earth orbit (at much higher speeds, say 7.66km/s for the ISS) and are successful almost every time. Rendezvous and docking of piloted spacecraft was extensively practised during the Gemini missions of the mid-1960s specifically to perfect the techniques used for the Moon missions.
I hope this has helped you.
I was wondering what kind of propulsion system would be needed to get a crew safely to the moon from low earth orbit?
Dear Natalie, thank you for your question. I am assuming from the way you have phrased it that you are aware that a substantial propulsion system would be needed to do this. The Apollo CSM was able to use its AJ10 main engine (burning Aerozine 50 as fuel and nitrogen tetroxide as oxidiser) to leave lunar orbit and enter a trans Earth coast trajectory. The Command Module entered the atmosphere at about 10km/s, this speed made it impossible to enter a low Earth orbit (about 7 km/s).
Basically and very roughly to go from the Moon to LEO means the spacecraft must lose about 3km/s. This could be done by aerobraking in the Earth’s atmosphere or firing rocket motors. The latter option is completely feasible but needs a considerable amount of propellant carried to the Moon.
Here are some links to speculations on how this could be done.
Moon-based Advanced Reusable Transportation Architecture: The MARTA Project
The Reusable Nuclear Shuttle: To the Moon, Again and Again
I hope that this has helped you.
Great site !
I am doing a paper on Apollo 11 that is due in a couple of months and I am very interested in a few questions.. Please help….How much breathable air was required for the three astronauts from lift off to splash down on the Apollo 11 mission? Can you tell me in liters? Also what kind of system was in place to guide the LM back to the CSM? If Both of these vehicles were traveling at 3,500 mph how were they able to find each other? Also I imagine rocket boosters were used to slow them down before they docked is that right?
Also a pretty basic question if there is no atmosphere in space what exactly does the thrust of the rockets push against?
Thank You so much .
Jo
Dear Jo, thank you for your kind words and questions.
An astronaut consumes approximately 0.8 kg (560 l) of oxygen per day. Note also that exhaled gas was òÀÜscrubbedòÀÝ through lithium hydroxide to remove carbon dioxide and rebreathed, so oxygen was not just inhaled once and discarded. The longest Moon mission, Apollo 17, spent 12.5 days roughly in space and had a crew of three, so thatòÀÙs a total of 30 kg. In practice they would have had a reserve, plus additional supply to cover the atmosphere lost every time the cabin was depressurised for an EVA.
Launching the LMòÀÙs Ascent stage and rendezvousing and docking with the CSM was done exactly how any spacecraft is launched from a surface to rendezvous with another in orbit, just like sending spacecraft to the ISS is done today. The orbit of the CSM was known very precisely, so at any given time its position in space could be accurately predicted. The launch position of the LM on the MoonòÀÙs surface was known to an acceptable degree of accuracy. By launching at the right time the LM could be put into a similar orbit to the CSM and be maneuvered to an eventual docking. A radar system with a 24 inch dish (which can be seen in several of the illustrations in the article) was used to locate the CSM and docking was performed manually by the commander through short bursts of the LMòÀÙs reaction control system thrusters. He was aided by the Crewman Alignment Sight, an optical device mounted at the docking window.
In lunar orbit the CSM and LM were both traveling at about 3355mph but their closing speed relative to each other during docking was òÀÜa few tenths of a foot per secondòÀÝ. The absolute speeds of the vehicles does not have any effect on how difficult the docking process is. Do note that docking spacecraft together happens all the time in Earth orbit (at much higher speeds, say 7.66km/s for the ISS) and are successful almost every time.
The exhaust is pushing against the rocket motor essentially but I am not sure that helps you. IòÀÙll try to explain.
In physics, momentum is a quantity obtained by multiplying a bodyòÀÙs mass and velocity (velocity is not just speed, it is speed in a set direction- an important distinction). Both theory and centuries of practice indicate that momentum is conserved; essentially meaning that it is never created or destroyed.
Imagine the LM floating in empty space. Inside it are tanks of propellant and a rocket motor. When the craftòÀÙs motor is turned on, the propellants are burned together in the combustion chamber, creating hot gases which are allowed to escape at very high speed out a nozzle, pushing the LM forward. Looking more closely, every second the motor operates, a relatively small mass of gas is emitted at high speed out of the motor as the exhaust. A small mass of gas multiplied by a high speed rearward yields a significant momentum in that direction. To balance the books (conserve momentum), the LM must move with an equal and opposite momentum, so it shoots forward (its mass will be greater than the gas in the exhaust, so its velocity will be lower, but the LMòÀÙs velocity will keep building up as long as the rocket motor is fed propellant.
Good luck with your paper, I hope this has helped you.
Your body absorbs the oxygen you breath in to survive so how is the oxygen reused?
Dear Semaj, thanks for your question, if I remember correctly only about 5% by volume of the oxygen in the air inhaled in each breath is used by the body, the rest is exhaled (along with carbon dioxide) in the breath out.
I hope this has helped you.
Good day. Thank you for your fascinating website and the information contained therein in regards to this extraordinary machine, the LEM. I am an electronics hobbyist and the electronics in particular of the LEM are fascinating. I would be most grateful if you could advise me of any books which go into great detail regarding the electronics of the LEM including all parameters such as power available, batteries, thermoregulation for the electronic systems (electronic systems are particularly sensitive to heat and it would be therefore interesting to know how all the systems were cooled or heated), radio communications systems and detailed schematic diagrams of these and frequencies used etc. Any information would be gratefully received. Thank you and best wishes.
Dear Duncan, thank you for your question. I suggest you start with the extensive collection of contemporary manuals link to this page (link).
Here are some books you may find useful too.
Sulllivan, Scott P, Virtual LM: A Pictorial Essay of the Engineering and Construction of the Apollo Lunar Module, Apogee Books, 2004
Steven-Boniecki, Dwight, Live TV: From the Moon, Apogee Books, 2010
Hall, Eidon C, Journey to the Moon: The History of the Apollo Guidance Computer, AIAA, 1995
Orloff, RW and Harland, DM, Apollo: The Definitive Sourcebook, Springer Praxis Books, 2010
Tsaio, Sunny, “Read You Loud And Clear!”: The Story of NASA’s Spaceflight Tracking and Data Network, NASA, 2008 (link)
I hope that these help you.
Thank you very much indeed. I will follow up on the links and books suggested. With best wishes from Duncan (Melbourne, Australia)
I am working on a National History Day project about NASA’s Manned Space Missions and this site is great! I was also looking for a contact (primary source) to ask a few questions about the LEM. Do you happen to know of anyone from Grumman that could be contacted that might be able to answer a few questions through email?
Dear Ashley, thank you for your question. Grumman doesn’t really exist anymore, it was absorbed by Northrop a while ago. Northrop Grumman’s contact page is at this link. The plant where the LM was designed and built has closed but there is a museum in the area which has preserved some of its history (contact details at this link). It could be your best lead. Good luck with your research.
Thanks for the great site. I read Jim Irwin’s book “To Rule the Night” awhile ago. One thing I only found out about a few years ago was how NASA wrung out every bit of scientific information they could from each mission including having some of the LM’s impacting the lunar surface after the final separation to generate seismic waves for the ALSEP’s left behind. I’m sure you know all about this as well as the spent S-IVB’s being used for the same role.
When it came to Apollo 15, everything was going as planned but as the crew was preparing for the journey home, Dave Scott and Jim Irwin realized that in the rush to meet the LM separation from the CSM at the right time, they had each assumed that their PPk’s(Personal Preference Kit) had been transferred by the other guy but sadly they had been missed. Aside from family mementos that were now in a man-made crater on the moon, Jim Irwin had his best friends wedding ring inside as well. Imagine having to explain that to your best buddy and his wife after returning.
I should mention that each astronaut had two PPK’s, and one of them was kept with the CSM which was the one that was auctioned off during Jim Irwin’s estate sale.ÿ¨ƒ
Did subsequent moon landings carrying people for return differ in design from the original lunar lander? How many landing structures are now on the moon’s surface including those from foreign nations”
Dear Ivan, thank you for your questions. They are mostly answered in the text of the article. There is a list of all spacecraft (human or robotic) which have landed on the Moon at this link but this does not include China’s Chang’e 3 lander.
I hope this helps you.
is it possible to make an air glider with retro thrusters to reduce the impact of landing?is it possible to make such a suit ?
If you look up “jet packs” on wiki, you’ll see a number of options that would theoretically have enough thrust and fuel to slow someone traveling at typical wingsuit speeds if that’s what you mean. However, it would require something the size of those jetpacks with current technology which means you wouldn’t be incorporating it into the suit. Also probably around 5 gallons of fuel or so, and would be very hazardous! Sounds fun though. Typically parachutes are used instead.