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Post by JayUtah on Jul 19, 2011 12:37:55 GMT -4
From the Apollo 11 press kit, page 64 Well there's your problem. The press kits are notoriously inaccurate and oversimplified. I guarantee the flight dynamics officers don't use the press kit to plan the missions.
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Post by capricorn1 on Jul 19, 2011 12:41:45 GMT -4
First, with the orbital component in the return trip, how was it possible for the command module to accelerate its velocity up to 36,194 fps? Second, with this orbital component, and with the added distance, how was the command module able to return back to Earth as quickly as it did? The same way it got there but in reverse? It was accelerated by Earth's gravity on the way back........and decellerated on the way there. eta: g'day cobber
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Post by pleasedebunkme on Jul 19, 2011 13:31:38 GMT -4
It amazes me how fast you people resort to ad hominem attacks. But, if we could all agree that NASA gave false information in the press kit, then perhaps that might be progress.
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Post by robdog on Jul 19, 2011 13:35:29 GMT -4
It amazes me how fast you people resort to ad hominem attacks. But, if we could all agree that NASA gave false information in the press kit, then perhaps that might be progress. Disagree. "False" implies an intention to deceive that innaccuracy and oversimplification does not.
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Post by JayUtah on Jul 19, 2011 13:41:18 GMT -4
It amazes me how fast you people resort to ad hominem attacks.I don't see any. Do you have a specific example you consider ad hominem? Your user name is "Please debunk me," and you have laid two specific allegations of inconsistency out to be discussed. Did you expect not to be challenged? You seem to expect some sort of generalized personal research service. No, this is a forum where we debate hoax theories, and you seem to be proposing one. But, if we could all agree that NASA gave false information in the press kit, then perhaps that might be progress. Let's agree that the press kit is not a suitable source for the details of Apollo planning and operations, whether it is correct or not. The press kit is a simplified view of the Apollo missions written by the public affairs office for the benefit of lay audiences. If you want to argue engineering specifics, that's a very poor source. I asked you several specific questions about your structural strength claim. If you were to answer those, that would also be progress.
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Jul 19, 2011 13:47:22 GMT -4
It amazes me how fast you people resort to ad hominem attacks. Please point one out because I must've missed it. No, NASA is trying to convey a general description for non-engineers and scientists of the flight path Apollo took on its return to Earth. The description given is "approximately" correct and good enough for the target audience.
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Post by echnaton on Jul 19, 2011 14:51:23 GMT -4
It amazes me how fast you people resort to ad hominem attacks.
Please specify inappropriate comments in a report to the moderator.
But, if we could all agree that NASA gave false information in the press kit, then perhaps that might be progress.
It is up to you to determine the quality of your information sources. The fact that something is written in a NASA public affairs release only means the release contains information that was intended for use by the target audience. It does not make the information comprehensively correct.
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Post by jdp1161 on Jul 19, 2011 15:46:40 GMT -4
I'll add my $.02 here as well. I don't post a lot here, but lurk a bunch, and I haven't seen anything here that would qualify as an ad hom. Hoax believers show up way too often as "a wolf in sheep's clothing".
Now, I don't have even the smallest amount of knowledge and experience that the others here have (just grew up during the space race and was facinated by it), so maybe I can speak to the press kit bit. I am exactly the kind of person it would have been made for. Whereas I wouldn't be able to make heads nor tails out of all the data given to you in the prior post, I can read the press kit quote and get a layman's understanding of "antipode". That's the point... It's written to provide general understanding to those who don't have technical expertise. Even I would never expect it to be a quoteable source of exact scientific data!
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Bob B.
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Post by Bob B. on Jul 19, 2011 15:59:56 GMT -4
The velocity of 36,194 fps is close enough to parabolic escape velocity to produce a large orbit. True. Apollo was in an elliptical orbit with a large semi-major axis. A little more, but that’s irrelevant. We’re not talking about the outbound trip. No need to speculate; Apollo was in an elliptical orbit. Correct. I’m not sure what you mean by “orbital component” – Apollo was in an orbit. All orbits are curvilinear; nothing moves in straight lines in space. We’ve been over this. The reentry, as defined by the 400,000 altitude, was not at the antipode. If not for Earth’s atmosphere, Apollo would have shortly passed through the perigee point and gone back out into space. As I said, it was in an elliptical orbit, so it would have continually orbited passing alternately through the perigee and apogee points. The only reason Apollo didn’t do this was that the perigee point was inside Earth’s atmosphere. Before the spacecraft could pass through perigee and begin going back out into space, it was overcome by the drag of Earth’s atmosphere. The drag slowed the capsule enough that it could no longer orbit, thus causing it to fall to Earth. Once Apollo broke out of lunar orbit it entered Earth orbit. In any orbit, velocity is greatest at perigee and least at apogee. Between perigee and apogee a spacecraft slows down as it moves away from Earth, and between apogee and perigee, it speeds up as it moves toward Earth. Apollo was moving toward Earth and, therefore, speeding up as it was pulled in by Earth’s gravity. Same answer. The spacecraft was constantly accelerating as it moved toward Earth and was able to cover the distance between the Moon and Earth in about three days. Look at the links I provided in Post #12. There’s a table providing spacecraft speed and distance versus time. See my previous answers. Apollo was in an elliptical orbit that continually increased in velocity as it approach perigee. Perigee was at the antipode of apogee. Had Apollo not encountered the atmosphere, which caused the orbit to decay, it would have passed through perigee, gone back out into space, and would have begun slowing down as it moved toward apogee. Of course you can. Read my previous answers. Please knock that off; no one here is being unkind to you. We are just trying to get you take responsibility for your claims and provide complete and valid arguments.
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Post by AtomicDog on Jul 19, 2011 16:04:13 GMT -4
Once again a HB spots a Magic Word (this time it's "antipode") used in a non-technical publication and tries to use it to prove that Apollo is a hoax.
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Post by pleasedebunkme on Jul 19, 2011 17:01:14 GMT -4
Bob B. That was very helpful. Thank you.
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Bob B.
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Post by Bob B. on Jul 19, 2011 17:06:00 GMT -4
Bob B. That was very helpful. Thank you. You are welcome.
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Post by ka9q on Jul 19, 2011 17:12:25 GMT -4
This might help you visualize the trajectory: Bob, those are great visualizations. Even though I knew the basic principles they still helped me see what's really happening. Here's a suggestion for if you ever update them: include the S-IVB for representative lunar-slingshot (e.g., Apollo 8) and lunar-impact (e.g, Apollo 14) trajectories. All it took was a small retarding push shortly after TLI (performed by dumping the residual LOX in the tanks). This slowed down the S-IVB enough to either hit the moon or fly past the trailing edge and be flung out of the earth-moon system entirely. And if you want to get really sophisticated, include estimated trajectories for the LM adapter panels that were jettisoned after TLI but before the LOX dump. They would accompany the Apollo stack rather closely all the way to the moon, and this might help debunk those persistent Apollo 11 "UFO" reports. The only problem I can see is that at this map scale they'll probably show up too close to Apollo to be easily distinguished from it. Of course, that's just the point.
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Bob B.
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Post by Bob B. on Jul 19, 2011 17:50:14 GMT -4
This might help you visualize the trajectory: Bob, those are great visualizations. Even though I knew the basic principles they still helped me see what's really happening. Thanks. Those visualizations helped me as well, particularly the free-return one. I was having a hard time seeing the trajectory from a fixed-moon perspective. After I saw it animated, I could see that the spacecraft approaches the moon from a more head-on direction than I was visualizing. Those are some good suggestions. I probably won't ever change what I already have because those animations are just generic anyway. I made several simplifications, such as making the orbits coplanar and putting the Moon in a circular orbit. If I ever get more sophisticated, I'll go full three-dimension and model a specific mission rather than just a generic one. I'll probably do Apollo 11 since I've already done a lot of the work on that one.
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Post by JayUtah on Jul 19, 2011 18:25:54 GMT -4
A couple of examples of where the press kit isn't a good source:
The Apollo 11 press kit gives the wrong field of view for one of the Zeiss lenses. The confusion is the very natural one between horizontal and diagonal field of view. It also makes some minor errors in the camera loadouts for the various missions. These are typical errors when journalistic writers must deal with technical explanations and mission parameters that change.
Luckily the press kit is not the authoritative source of photography information for the Apollo missions.
We've already had to deal with the effects of the simplified diagrams of Apollo orbits and trajectories. They're obviously not to scale, and they are coerced to lie in a single plane for clarity. They don't represent the orbital inclination of the translunar and transearth trajectories. This is doubtless a deliberate simplification, but it is not considered dishonest.
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