|
Post by Obviousman on Nov 21, 2009 5:11:17 GMT -4
Bob, that is absolutely stunning. Great work. BZ, fella.
|
|
|
Post by drewid on Nov 21, 2009 10:46:14 GMT -4
Nicely done Sir Bob. That shows it beautifully.
I'll amend my colours to match those in your final radiation level diagram and repost the 3D version, and do some sort of animation showing dosage over time or something. The amount of time spent in the various zones matches what I'd estimated pretty closely I think. I can't get onto rendering/animating anything today, but I might get a chance to have a look at it tomorrow.
|
|
|
Post by JayUtah on Nov 21, 2009 11:37:40 GMT -4
That is outstanding, Bob! I believe it answers just about any question that has been asked, or likely could be asked about the translunar trajectory and the radiation environment.
|
|
Sabine
Mercury
A closed mouth gathers no foot
Posts: 12
|
Post by Sabine on Nov 21, 2009 12:22:05 GMT -4
Wow, that's really clear even to a complete lay person like me (I skipped all the math). Nice work!
|
|
|
Post by gwiz on Nov 21, 2009 12:47:46 GMT -4
|
|
Bob B.
Bob the Excel Guru?
Posts: 3,072
|
Post by Bob B. on Nov 21, 2009 13:03:36 GMT -4
Thanks, folks. This was something that I wasn't exactly sure what it was going to show when I started. I just followed the math to its inevitable conclusion. The results are beautiful! The more one investigates Apollo, the more apparent it becomes just how ingenious and skilled the designer were.
|
|
Bob B.
Bob the Excel Guru?
Posts: 3,072
|
Post by Bob B. on Nov 21, 2009 13:09:47 GMT -4
|
|
|
Post by LunarOrbit on Nov 21, 2009 13:33:43 GMT -4
Great work, Bob! Keep it up and there won't be a need for this forum anymore because there won't be any hoax believers left.
|
|
|
Post by archer17 on Nov 21, 2009 14:10:46 GMT -4
Kudos Bob B. Great work, Bob! Keep it up and there won't be a need for this forum anymore because there won't be any hoax believers left. It was great work although, as far as the more irrational HBers are concerned, I don't think anything would change their need for a conspiracy...the adage about leading a horse to water comes to mind.
|
|
|
Post by LunarOrbit on Nov 21, 2009 14:35:10 GMT -4
It was great work although, as far as the more irrational HBers are concerned, I don't think anything would change their need for a conspiracy...the adage about leading a horse to water comes to mind. True, but I think at some point we can just cast off those few irrational people and ignore them the same way we ignore flat Earthers. As long as the people who are on the fence now have their concerns addressed I will be happy.
|
|
|
Post by fm on Nov 21, 2009 15:30:48 GMT -4
Well thanks for are all your efforts. There is a lot of good information there. And trust me when I say I am really trying to picture what happened with Apollo and the VABs. But... and of course you must have seen it coming, I do have some questions: For one can you clarify for me the following:In your Translunar chart the "Distance from Earth (m)" column, does (m) represent in meters or miles? In other words, should the first line be read as 6,712,595 (million meters or miles) or (thousand meters or miles)? Another question about your chart is:Are your numbers derived from numbers you got from Apollo documentation or did you use simply a formula to plot the data? Because Im trying to find where the following happens in your chart, can you point (maybe using your GET) that out using the following as markers: 01:01 PM T+003:29 SM high gain antenna is deployed 02:12:01 PM T+004:40:01.72 SPS ignition for a 2.93-sec evasive burn, imparting ∆V = 13.4 mph and placing the spacecraft a safe distance from the Saturn IVB when it performs its propellant dump to target lunar gravity assist into solar orbit. Latitude after burn = 21.16° N, longitude 68.46° W, height = 19134.4 mi, flight path angle = 64.25°, heading = 113.74°, speed = 9997.5 mph, pericyntheon = 193 mi 03:00 PM T+005:28 CSM initiates 10-min water dumpOk, now here is where I have been having issues with from the get go when I made my second post in this thread. In your chart "Distance From Earth" you state: The red markers indicate the spacecraft position in 10-minute increments, with four hours total being shown. Am I correct in saying that it took about 4 hours for Apollo to reach 10 earth Radii? Now what I have read about the size of the VABs, is: The large outer radiation belt extends from an altitude of about three to ten Earth radii (RE) above the Earth's surface. Its greatest intensity is usually around 4–5 RE. or even Radiation around the Earth is a radial distance of 107,400 kmIf you were only showing the time it took Apollo to reach 10 earth radii. Then I wouldn't have an issue with your chart. But then you took the same plot line, in which you state: As the spacecraft swings around Earth and heads out toward the Moon, it travels in the direction where the geomagnetic plane slopes away from it. In fact, by the time Apollo 11 reaches a distance of about three Earth radii, the geomagnetic pole is tilted almost exactly in the direction of the spacecraft, resulting in maximum separation between Apollo 11 and the geomagnetic plane. This optimal alignment is maintained until the spacecraft is well beyond the limits of the VAB.And applied it to those diagrams where I don't see that "swing around Earth" and I don't see Apollo out of the VABs by 3 earth radii. This is what Drewid attempted to do, but his VAB was very small compared to the Earth. Also, the three diagrams you use are showing the VABs to be 6, 7, and 3 radii long, and about 4 radii wide. So my question is why not use a diagram showing the VAB extending to 9 to 10 radii, or 107.000 kms long, and the VAB being 8 to 10 radii wide to destroy any doubts? Can you show, using your TOP VIEW, SIDE VIEW, and possibly your END VIEW diagrams, with the point and time where you see Apollo entering and leaving the VABs, corresponding to your "Distance from Earth" chart? Your calculations have lead you to state that:Once again we see that Apollo 11 left the vicinity of the VAB after about 90 minutes.I wonder how many people here will agree with that, or will modify their initial answers: Czero 101 The longest Apollo mission was Apollo 17, clocking in at just over 12 1/2 days. On average, the other Lunar missions were roughly 9 days each. When passing through the Van Allen Belts, the trajectories used ensured that the spacecraft only passed through the weaker edges of the belts, limiting the astronaut's exposure to roughly an hour each way. AstroSmurf The two hours of exposure refers to the passage through the Van Allen belts, which would be much the same duration and intensity no matter what the total mission duration - in reality, about 20 minutes each way through the densest parts.
swank23 How exactly is the Apollo mission not considered long term duration? At first, everyone seems to want to say that the astronauts were only exposed to 2 hours of radiation, but that is not true. here are two more articles for you to chew on. "Radiation was a definite concern for NASA before the first space flights, but they invested a great deal of research into it and determined the hazard was minimal. It took Apollo about an hour to pass through the radiation belts - once on the outbound trip and once again on the return trip.
Bob B. I don’t see anyone quoting this two-hour figure except you. We’re saying the astronauts were exposed to radiation for the full duration of the missions, but the accumulated dose over that relatively short period was not dangerous.
Bob B. he referenced web page is addressing the Van Allen Radiation belt issue saying that the spacecraft was in the presence of that particular source for only about two hours. This doesn't mean the astronauts didn't receive lower levels of radiation from other sources throughout the entirety of the missions. Even still, the astronauts' total radiation exposure, as measured by dosimeters, was only about one rem.
Jason Thompson Apollo deliberately missed the van Allen belts, so what information do you expect them to have about them that could be better than from satellites that specifically study them?
JayUtah It's a bit more involved than that. An orbit is an elliptical path lying within a plane inclined at a certain angle and orientation with respect to its primary (Earth). The translunar trajectory is simply an elongated orbit. The exact interaction between any such orbit and the Van Allen belts transcends crude 2D diagrams or abstract altitudes. It is a fully three-dimensional problem. The exposure profile for transiting the trapped radiation belts must be derived and then integrated over time. The 1-hour figure derives from this profile, representing one hour of significant exposure along that profile.You can see a range of opinions of the entire trip from hours, less than an hour, no time at all and that the exposure was, I suppose, representational to the total exposed radiation. How confident are you in your findings? Now here is my question, which I have asked before, according to your figures, if you have any, how long did it take for Apollo on its return flight to fly through the VABs and on what inclination? Because if we assume it was equal, which I dont see how that's possible, you have a total transit time of 3 hours in the VAB. Right? Ok thats it for now
|
|
|
Post by BertL on Nov 21, 2009 15:39:51 GMT -4
For one can you clarify for me the following:In your Translunar chart the "Distance from Earth (m)" column, does (m) represent in meters or miles? In other words, should the first line be read as 6,712,595 (million meters or miles) or (thousand meters or miles)? I'm not Bob B., but I'm fairly sure the distance from Earth is shown in meters. Commas are not indicators of decimals here; hence, the first line is approximately 6.7x10^6 meter (or about 6.7 million meter).
|
|
vq
Earth
What time is it again?
Posts: 129
|
Post by vq on Nov 21, 2009 16:03:18 GMT -4
You can see a range of opinions of the entire trip from hours, less than an hour, no time at all and that the exposure was, I suppose, representational to the total exposed radiation. How confident are you in your findings? The VAB's have fuzzy edges; they do not suddenly stop at a certain point in space. Exactly how long you consider the spacecraft to be in the belts depends on where you choose to draw the line. This is probably why you have received a range of answers.
|
|
|
Post by gillianren on Nov 21, 2009 16:20:22 GMT -4
Now here is my question, which I have asked before, according to your figures, if you have any, how long did it take for Apollo on its return flight to fly through the VABs and on what inclination?Oh, for the love of Gods. Are you paying any attention at all to what anyone says? My cat understands that you can't give an answer to that without certain numbers plugged in by now, and he's the dumbest cat I've ever had. ETA: Okay, try this. I came up with it while explaining the concept to my boyfriend, my own personal gauge of "what normal people know and understand." Let's say someone has put up a line of sprayers, and you're planning to walk under them. Now, the way they're set up, there's a place where you get kind of vaguely sprinkled upon, and the waterfall gradually gets heavier until you're just being "rained" on, then ebbs again. How long did you spend under the sprayer? Are you going to start from where the breeze is blowing occasional random droplets on you? When you walk directly under the beginning of the spray? When you're in the real, heavy part of the spray? What counts?
|
|
Bob B.
Bob the Excel Guru?
Posts: 3,072
|
Post by Bob B. on Nov 21, 2009 16:51:51 GMT -4
For one can you clarify for me the following:In your Translunar chart the "Distance from Earth (m)" column, does (m) represent in meters or miles? In other words, should the first line be read as 6,712,595 (million meters or miles) or (thousand meters or miles)? m is meters. 6,712,595 m is 6 million meters and some change. Another question about your chart is:Are your numbers derived from numbers you got from Apollo documentation or did you use simply a formula to plot the data? The data used to determine the orbital elements came from NASA record documents. Everything else is mathematically derived. Because Im trying to find where the following happens in your chart, can you point (maybe using your GET) that out using the following as markers: ) 01:01 PM T+003:29 SM high gain antenna is deployed 02:12:01 PM T+004:40:01.72 SPS ignition for a 2.93-sec evasive burn, imparting ∆V = 13.4 mph and placing the spacecraft a safe distance from the Saturn IVB when it performs its propellant dump to target lunar gravity assist into solar orbit. Latitude after burn = 21.16° N, longitude 68.46° W, height = 19134.4 mi, flight path angle = 64.25°, heading = 113.74°, speed = 9997.5 mph, pericyntheon = 193 mi 03:00 PM T+005:28 CSM initiates 10-min water dump The T+ times referenced above are GET. For instance, T+003:29 is the same as 003:29:00 GET. Ok, now here is where I have been having issues with from the get go when I made my second post in this thread. In your chart "Distance From Earth" you state: The red markers indicate the spacecraft position in 10-minute increments, with four hours total being shown. Am I correct in saying that it took about 4 hours for Apollo to reach 10 earth Radii? That is approximately correct. Now what I have read about the size of the VABs, is: The large outer radiation belt extends from an altitude of about three to ten Earth radii (RE) above the Earth's surface. Its greatest intensity is usually around 4–5 RE. or even Radiation around the Earth is a radial distance of 107,400 kmWhat is the flux out that far? The energy? Why should we give a rat’s ass about the VARB out to 10 Earth radii? And applied it to those diagrams where I don't see that "swing around Earth" The diagram is not a 3D rendering. It shows distance from Earth in two dimensions, which is all we require to know where the spacecraft is located in relation to the VARB. and I don't see Apollo out of the VABs by 3 earth radii. It’s not. So my question is why not use a diagram showing the VAB extending to 9 to 10 radii, or 107.000 kms long, and the VAB being 8 to 10 radii wide to destroy any doubts? The VARB maps I’m using show the flux at various energies. The maps don’t show the VARB extending beyond 6 or 7 radii because the particles beyond that distance have energies lower than those being mapped. At those far distances, the particle energy is so low that it is of no consequence – the particles can even penetrate human skin. Can you show, using your TOP VIEW, SIDE VIEW, and possibly your END VIEW diagrams, with the point and time where you see Apollo entering and leaving the VABs, corresponding to your "Distance from Earth" chart? I can but I won’t. I’ve already done enough. Your calculations have lead you to state that:Once again we see that Apollo 11 left the vicinity of the VAB after about 90 minutes.I wonder how many people here will agree with that, or will modify their initial answers: I also wrote: “The far edge of the electron belt was reached in about 90 minutes, the inner zone was traversed in about 30 minutes, and the region of the most energetic particles was skirted in just about 10 minutes.” So there are many answers that can be given depending on the precise question being asked. Since you are incapable of asking a precise question, you are getting a lot of different answers. The problem is not with the answers, it is with the question. You can see a range of opinions of the entire trip from hours, less than an hour, no time at all and that the exposure was, I suppose, representational to the total exposed radiation. How confident are you in your findings? I’m very confident in the spacecraft’s position versus time. How that relates to the VARB depends on what specifically you want to know. Now here is my question, which I have asked before, according to your figures, if you have any, how long did it take for Apollo on its return flight to fly through the VABs and on what inclination?Now that I’ve shown you how to do it, why don’t you figure it out for yourself? Because if we assume it was equal, which I dont see how that's possible… Why you think a similar transearth trajectory is not possible? …you have a total transit time of 3 hours in the VAB. Right? Depends on how you define the VARB. Transit time through what type of particles and at what flux and energy?
|
|