THE STRANGE DESCENT OF APOLLO 17
 They say: "The descent engine runs at 10% thrust for 26 seconds to give the computer time to sense the LM's center of mass. It will then go to its high thrust setting".  It is important that the line of thrust is aligned with the center of mass, otherwise a disalignment torque could be created, which would cause the LM to turn.  The descent engine could be swivelled, which was allowing to align its thrust with the center of mass, so to avoid the disalignment torque, and so the rotation of the lunar module. When the propellant tanks are emptying, it generates a shift of the center of mass, which would make that the main engine would not be aligned any more with the center of mass if the engine was not swivelled to realign its thrust with the center of mass. But, at the start of the powered descent, the tanks were still full, and so the engine's thrust was still aligned with the center of mass; thus this adjustment was useless. It was useful only after the tanks had emptied, and the center of mass had consequently shifted, but they don't make the alignment again later though it would have been useful to make it at that moment. |
 They say: "At 30-second intervals,if workload allows, the crew compare their progress against a table of expected values". Oh really, workload? What workload, the computer is doing all the job. Making this comparison was meaning reading all the flight values; but this was taking time, for they could not read them all in the same time, the display was too limited. This means that they would not read the different values at the same time, and thus would read values which are not synchronized with each other. Therefore comparing them with a table of expected values makes no sense. |
 They say: "The spacecraft has two guidance systems: PGNS is the main: AGS is backup, intended only for an abort. The crew compare them to see if their state vectors (velocity and position) agree." The two systems update their state vectors from the same data with the same equations, so their state vectors will necessarily be the same. Now comparing them makes no sense, for it takes time to read the state vectors on each of the computers (because of the limitation of the display), and the result is that the state vectors, which constantly change, will not correspond with each other. It would only make sense it they could instantaneously acquire the state vectors as a whole on each of the computers, but this facility was not provided. |
 They say: "MCC have measured their velocity using the S-band radio system and worked out the down range error in the targeting" The velocity measured with radar signals inserted in the transmission gives a very rough result. But MCC does not need to measure the velocity that way, for it is perfectly known, as the LM starts from the orbital speed of the starting orbit which is perfectly known, and from a null vertical speed (since the orbital speed generates a centrifugal force which perfectly counters the lunar attraction). So why measure the velocity to obtain an imprecise result when the velocity is in fact already perfectly known with precision? |
 They say: "They are giving the crew an offset value, 3400 feet, which will compensate for the error and fool the LM to land in the right place." Instead of using a perfectly known velocity, the ground prefers to use a roughly measured velocity. As there is a difference between the theoretical velocity and the rough measured velocity, the ground gives the crew a correction corresponding to this difference. But, as the error does not come from the theoretical speed, but from the measured speed which is imprecise, so, if the crew applies the correction given by the ground, they will add to the guidance an error which was not existing instead of correcting an existing error. This is of course a joke from the engineers. |
 They say: "H-dot represents their vertical speed or their rate of descent" No H-dot does not represent a vertical speed, but a horizontal position, which is quite different. |
 They say: "Turning a system off, then on, is a common way to clear anomalous conditions in electronic systems". This is of course completely ridiculous; for instance, is the computer was cut off, and on, it would lose its current data it needs to calculate the next data. |
 They say: "One of the position numbers in the AGS indicates how far left or right (south or north) of their ideal track they move." The lunar module is naturally following its trajectory, it has no reason to drift left or right, the guidance (using gyroscopes) constantly makes corrections to remain on the good trajectory. The AGS has no way to know if the module drifts from its normal trajectory, for the guidance constantly compensates the drift. It would be stupid to think that the AGS would know how much the LM drifts from its normal trajectory, and the guidance would do nothing to correct this drift. And the ideal trajectory is the one which brings the lunar module near the lunar surface with small horizontal and vertical speeds, it does not imply a specific direction. So this is to be seen (again) as a joke. |
 They say: "The ball is the FDAI. It displays their attitude by rotating a ball and it should be showing a pitch angle of 82 degrees".  Right the FDAI allows to display the roll and the pitch. But it is graduated 5 degrees by 5 degrees, which means that it could indicate a value of pitch between 80 and 85°, but not precisely 82°. |
 They say: "As the burn continues, and the LM becomes lighter, the g_force on the crew increases. They feel heavier." This is utterly ridiculous. The g-force does not increase because the LM becomes lighter, but because, as the horizontal speed decreases, so does the centrifugal force, which means that it compensates less the lunar attraction, and so the LM becomes more subjected to the lunar attraction. |
 They say: "Schmitt checks the voltage on the "ED Batts", batteries that power the explosive devices (EDs) that would separate the stages in abort." Schmitt tells the ground that the batteries' voltage is 37.2 volts. 37.2 volts? But the normal voltage is 28 volts! Is he sure that he has not misread? 27.2 volts would be more normal. |
 They say: "Before PDI, the LM was yawed left 70 degrees to improve the angle of the high gain antenna to Earth. Now they reduce the yaw to 20 degrees left (or 340 degrees) so that the landing radar can see the surface". 1) The LM does not need to yaw to allow the high gain antenna to see the earth, for this one can yaw by its own. 2) The way the landing radar is placed, yawing the LM does not help it to better see the lunar surface. And the landing radar should be conceived to be able to see the lunar surface all along the descent without the LM having to change its attitude to allow it to see the lunar surface. |
 They say: "They compare the Radar's value for height with the computer's. This difference is known as 'Delta-H". It is not too big. The Radar's data can be accepted by the computer." Here they repeat the same trick as in the descent of Apollo 11. The radar gives a measured value for this Delta-H (difference between the initial altitude and the altitude given by the radar), and the guidance computes an estimated value for this Delta-H, and the Delta-H is not the difference between these two values. And, even supposing that the Delta-H effectively represents the difference between the height measured by the radar and the height calculated by the guidance, why would they check something which is automatically updated by the computer? Because they are afraid that the computer would screw? The problem is that, on this primitive computer, they can't get all the guidance values in the same time, but separately, one at a time (with a program for each); it means that they are going to compare values which are not synchronous with each other, so their difference will not be significant. |
 They say: "The landing Radar's data will now be gradually "incorporated" into the guidance equations." When available, the data of the landing radar is not "gradually" incorporated into the guidance equations, but immediately used to make the calculations. "gradually" means nothing in the guidance. |
 They say: "Eventually the radar and the computer will converge on the same values for altitude and velocity." The radar only gives a value of altitude not a velocity; the computer obtains a velocity from the altitude by deriving it; so the computer has nothing to compare its computed velocity with. |
 They say: "Delta-H is comparing the PGNS with landing Radar. As the Radar detects the mountains east of the site, it affects Delta-H, it affects Delta-H, a good sign that it's working well." This is a good joke: Because the Delta-H is a difference of height between two events and the mountains are not at the vertical of the lunar module. |
 They say: "Cernan Yaws the LM a further 20 degrees right so that it is facing directly up". Just before yawing, Cernan was seeing the earth through the window. On the site of Apollo 17, the earth had an elevation of 52°, it means, that, when Cernan was seeing the earth through the window (and saying he was only seeing it), the direction of the LM's front was making with the horizontal an angle close to 50°. He then yaws the LM so that it directly faces up, so that the direction of the LM's front now makes an angle of 90° with the horizontal; that makes a difference close to 40° with the previous position, but Cernan only yaws the lem of the half to cover that difference! That's the magic of the moon! |
 They say: "The engine is now operating in an adjustable range so the computer can ride its thrust to fly towards the ideal trajectory." The engine cannot be adjusted in range, only in thrust, and its thrust is automatically adjusted by the guidance so to follow the calculated trajectory. So this phrase means nothing, and directly comes out of the delirious mind of the engineers. |
 They say: "Of the two independent systems for measuring the propellant quantity, the more conservative is selected to be monitored." A system may appear to be more conservative at a given moment, and not some time later. It means that they should constantly monitor the two measuring systems, and each time retain the lower value of the two systems. They had already played this trick in the descent of Apollo 11. |
 They say: "Schmitt will 'update" the AGS by passing it the state vector numbers from the PGNS." The AGS normally does not need to be updated with the state vectors of the PGNS as it uses the same equations and data, so obtains the same state vectors. Now, updating the AGS from the PGNS could have made sense if the state vectors could have been instantaneously updated from the ones of the PGNS. Indeed, to make the updating, Schmitt must first read the 6 values for the state vectors on the PGNS, and then type them on the AGS, but this takes time, and, by the time that Schmitt has finished inputting the state vectors into the AGS, they have already changed on the PGNS, which means that Schmitt in fact has updated the AGS with wrong state vectors, not synchronized with the ones of the PGNS; this is as much more absurd that, before updating the state vectors on the AGS, they were probably correct on this one. It is obvious that, if it had been necessary to update the state vectors on the AGS from the PGNS, the engineers would have devised a system to make a direct transfer between the two computers, without needing the intervention of an astronaut (moreover the astronaut could make a typing error). |
 They say: "Schmitt manually feeds altitude information from the radar into the AGS" This is the same trick as the previous one. The altitude information should be directly fed to the AGS, Schmitt should not have to input it himself, for, by the time he has finished inputting it, it has already changed. |
 They say: "As soon as P64 begins, the LM will pitch forward (or pitch over) to allow more visibility of the landing site."  And: "Challenger pitches forward to a more upright attitude as Program 64 begins the approach phase of the descent"  The lunar mdule should definitively not pitch just to allow to view the lunar surface. If the astronauts need to view the lunar surface, they should be provided with an optical system allowing them to view it. Indeed, when the lunar module has lost most of its horizontal speed, the centrifugal force is no more here to counter the lunar attraction, which means that the LM must keep a vertical attitude so that the lunar module can counter the lunar attraction with its engine. If the LM was flying horizontally, the moon would attract it, and it would crash on the moon.  Some could say: The LM does not not need to fly completely horizontally, it can fly in bias so that a part of its thrust can counter the lunar attraction. Yes, but in that case the horizontal part of the thrust would rapidly make the lunar module gain an important speed, which is not advisable.  If the lunar module was making the maneuver we see it make on the video, it could not remain that stable, we would see it jerk and gain horizontal speed. What we see is completely unrealistic. |
 They say: "The computer can now indicate to Cernan where on the surface it is taking them. This is the LPD (Landing point designator)".  And: "Schmitt is reading angles from the computer that tell Cernan where to sight past lines parked on his window. This is the computer's aim point."  And: "Cernan redesignates the LM to respond by temporarily rolling to the left." This needs an explanation. |
 In order for the astronauts to be able to tell the computer where exactly to land the lunar module, they were using a system called "landing point designator", using a graduated scale printed on the window.  An astronaut was reading on the computer's display on what graduation of the scale the computer was seeing the landing point and announcing it to the astronaut who was watching through the window. The second astronaut was reading on the scale on what graduation he was seeing the desired landing spot, and then was making on a hand-controller as many actions as the difference between the computer's graduation and his own to tell the computer how to correct its trajectory in order to reach the desired landing point.  But this system was senseless, for it was accumulating the delays. But the time that Cernan had made his actions on the hand-controller, his desired landing spot was already on a different graduation, and the landing spot seen by the computer was also on a different graduation than the one which had been announced by Schmitt. It is quite obvious that this system had no chance to work and that the LM was almost sure to miss the desired landing spot. |
 So, was there a better system to designate the desired landing spot? Of course there was; Cernan should have watched through an optical system and aligned a reticle on the desired landing spot, and pushed a button to tell the computer the reticle was on the desired landing spot, and the computer would have immediately known the location of the desired landing spot. But how could the computer know how Cernan was manipulating the optical system?  Very simple, because the optical system would make turn two wheels disposed perpendicularly which would each send pulses that an electronic system could count or decount to update the position in each direction.  This is besides the way a mechanical mouse works; as you move the mouse, a spherical ball turns which makes turn two wheels disposed perpendicularly, which each send pulses to an electronic circuitry as they turn, which are counted or decounted to update the position in the two directions that the mouse moves. And if you ask if this technology was existing in the time of Apollo, yes, it was, for it was a relatively simple technology, available and used in this time. This means that the engineers could perfectly have conceived a rational system which would have given good results instead of this completely irrational system which had every chance to badly work. |
 Imagine if, instead, or having your mouse pointer moving on the screen as you move the mouse...  ...You had to click the mouse as many times as the distance between the current position of the mouse and the new desired position to move it to the new desired position...  ..You would probably very quickly throw your computer through the window! And; in the landing point designator of Apollo, it was still worse, for Cernan was not seeing the position of the computer's landing site on the graduated scale, but Schmitt had to tell him after having read it on the computer's display! One more proof that the engineers didn't intend to conceive a rational system for a lunar module that they they perfectly knew that it would never land on the moon. |
 They say: "The computer is now in Program 66 which allows Cernan control of the LM's attitude, and therefore the direction of the rocket thrust".  No, Cernan must certain mot change the direction of the rocket thrust. The main engine must absolutely remain vertical to counter the lunar attraction, and it is the horizontal thrusters which must be used to laterally move the lunar module.  It is absolutely not advised to pitch the lunar module to move the lunar module. The rotation of the lunar module is not easy to control, because the thrust of the lateral thrusters cannot be adjusted, and that their control is slow. Moreover, the main engine would give a too important thrust and would increase too much the horizontal velocity of the lunar module.  Thence it is much better to keep the main engine vertical, and to only move the lunar module with the horizontal thrusters, which can move the lunar module in all directions. But to move the lunar module in one direction, the corresponding thrusters must not be permanently fired, for, as there is no air resistance on the moon to slow down the lunar module, the horizontal speed would keep increasing.  So, they must only be fired during the necessary time to acquire the desired speed, and then shut off. Conversely, to stop the lunar module, the thrusters pushing in the opposite directions must be fired just the time to cancel the horizontal speed. |
 They say: "Additionally, Cernan can adjust how fast they descend by flicking the rate of descent switch up or down. Each flick adjusts by one foot per second". No, absolutely not, the astronauts must not have the control of the descent speed, it is much too dangerous. Indeed, they are close to the lunar surface, and, if they were programming an inappropriate descent speed, they would almost be sure to crash on the moon. It is up to the computer to control the descent speed, for it can better see the lunar surface with its radar than the astronauts, and it can automaticallty adapt the descent speed to the remaining height.  But, if having a switch to control the descent speed makes no sense, on the other hand having one to control the lateral speed does make sense. Indeed, it would allow the astronauts to laterally move the LM a little fast when it is still at some distance from their desired landing point, and slower when they come closer to it. |
 They say: "The dust raised by the engine exhaust is much less than that seen on the other sites." But this is not dust we see projected from the lunar ground...  As said in a previous video, it is very obviously beams of light instead. |
 They say. "1.5 metre-long probes hang from three of the footpads. When one of them touches the surface, a lamp will illuminate in the cabin. This a cue to stop the engine."  There were indeed probes hanging under the feet of the lunar module which were detecting the lunar ground a little before the lunar module was itself touching the ground. At this moment the engine had to be shut off, for it could have been dangerous to have it still firing as the lunar module was resting on the ground, as its skirt was quite close to the lunar ground, and it could have damaged the LM.  Indeed, you can see on this photo of Apollo 11 that the engine's skirt was quite close to the ground when the lunar module was resting on the ground, and it could even be worse, for there might be a bump just under the engine, making the skirt still closer to the ground, as the lunar module was landing on an unknown ground which might not be flat. |
 But, to light the lamps which were warning the astronauts they had to shut off the engine, the electronic circuitry detecting the probes was using electromechanical relays I have circled. The property of an electromechanical relay is that it can automatically close a switch when it is activated. This means that this circuitry could have directly shut off the engine without requiring the intervention of the astronauts...especially since, to just light a lamp, it is not necessary to use an electromechanical relay, it can be done just with transistors. It would have been safer to make an electromechanical relay directly shut off the engine, for it would have avoided the unpredictable human reaction time of the astronauts. |
 And it was even worse, because the button they had to press to shut the engine off was not directly changing a switch shutting the engine off, but was activating an electromechanical relay (circled in green on the schema extracted from the NASA documentation) allowing to shut if off; but, instead of closing a contact (circled in red on the schema) which was allowing to send a current into the coil of the electromechanical relay, the button, when pressed, was opening it instead, and it is when it was released and closing the contact again that it was sending the current into the coil of the electromechanical relay, which was then only shutting the engine off.  It means that the engine was not shut off when they were pressing the button, but after it had been fully released.  This was adding a new delay for shutting the engine off. And, in the excitation of the moment, they might forget to release the button, and let their finger on the engine stop button, with the consequence that the engine would still be firing when the LM would touch the ground, which might have dramatic consequences. But it was out of question for the NASA engineers to conceive a normal safe system for a lunar module which would never land on the moon. |
 Observe the landing probe's shadow I have circled on this image I have extracted from the video (and on which I have added a little luminosity, for it was a little dark).. This landing's probe shadow is abnormally long and thick.  To give you an idea, this close-up from a photo of Apollo 16 shows a leg of the lunar module with a landing probe at its foot; see the big difference between the two. And this anomaly cannot be explained by the fact that the probe would be closer to the ground, for it is only 1.5 meter long, and its thickness is constant on the image.  And observe the landing probe of the other visible leg on this image extracted from the video (on which I have added a little luminosity to make it more visible). It's thinner than the first one, but we can see that its direction is not vertical while it should be. |
 Then observe the shape of the shadow.  The LM landed at sunrise, which means that the sunlight had a low inclination, I represented with the green arrow (besides, we can see on the photos of the mission that the LM has a quite long shadow). But the way we see the shadow appear on the video, it is obvious that it appears like the sunlight was consistently more vertical, along a direction I have represented with the red arrow. This is inconsistent. |
 And there is a final surprise on the LM's shadow after the lunar module has finally landed.  Observe the S-band antenna on the shadow, I have circled in red. You can clearly see that it is oriented toward the back of the lunar module.  But this is not what we see on the photos of the mission.  Indeed...  On this photo, the S-Band antenna is oriented completely differently , which is besides logical, given the relative positions of the sun and the earth (The S-Band antenna must always point toward the earth, since it must communicate with it).  So, we have a disagreement here: The S-Band is oriented toward the back of the LM on the shadow of the LM just after the LM has landed, but it is later oriented differently! So, is it a lunar magic trick again? |
 But, after all, God is here to watch after the mission, so it can't fail! |
