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Post by Count Zero on Mar 29, 2010 21:08:25 GMT -4
Wow! Great find, Raven. Concise and to the point.
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Post by JayUtah on Mar 29, 2010 23:43:39 GMT -4
It explicitly says, "Seven day flights along the trajectories of the Zond-5 and 7 probes are safe from the radiation point of view." Even more explicitly, it qualifies this assessment by saying, "should no solar flare [occur]." This is important because it shows the Soviets were thinking along the same lines as the Americans. Apollo-type missions of very short duration didn't have to worry about solar flares or ejections since they were not likely to occur during that time.
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Post by ka9q on Apr 2, 2010 20:42:45 GMT -4
Launching into Earth orbit with an inclination of about 32.5 degrees was common NASA practice going all the way back to the first orbital Mercury flight. Off the top of my head, I don't recall the exact reason for this. For earth orbital missions it may be as you suggest, to improve coverage by their ground stations. For lunar missions I can think of an additional advantage for parking orbits in the 30-35 degree range: launch window flexibility. The Saturn V guidance system could compensate for a change in launch time by changing the launch azimuth as the earth carries the launch site eastward. From KSC you can reach a 35 degree orbit by launching either a little north of east or a little south of east, with a change in the resulting plane. Since you want to launch into an inertially fixed plane that includes the moon at arrival, this gives you some flexibility in the launch time.
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Post by chew on Apr 2, 2010 21:38:08 GMT -4
I had always thought it was because Cape Canaveral was at 28.5N latitude and the minimum orbital inclination equals your latitude (unless you expend butt tons more fuel). So everything was designed around that limitation. And we didn't want to rent from any countries on the equator.
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Post by ka9q on Apr 3, 2010 3:22:48 GMT -4
I had always thought it was because Cape Canaveral was at 28.5N latitude and the minimum orbital inclination equals your latitude Sure, you're entirely right - your latitude establishes your minimum orbital inclination unless you spend a lot of extra fuel on a dogleg maneuver. My point is that by launching due east from KSC, you enter an inclination of 28.5 degrees. As you swing either north OR south from due east, your inclination begins to increase above 28.5 degrees, but the orbital planes are different - they cross the equator at different right ascensions. So if your target orbit is, say, 32 degrees, you have two chances to hit the same inclination and right ascension at two different times, one by launching to the north of east and another by launching to the south of east. This widens your launch window, which is a significant practical advantage with a rocket and spacecraft as complex as a Saturn V and Apollo.
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Post by chew on Apr 3, 2010 11:50:38 GMT -4
Ah, got it.
That's cool.
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Post by JayUtah on Apr 5, 2010 12:17:52 GMT -4
As you swing either north OR south from due east, your inclination begins to increase above 28.5 degrees, but the orbital planes are different - they cross the equator at different right ascensions. So if your target orbit is, say, 32 degrees, you have two chances to hit the same inclination and right ascension at two different times. Indeed. Most missions today have constraints on the orbit they are intended to enter. An LEO rendezvous mission, for example, must launch into the plane of the orbit they are trying to match. For an inclination greater than the launch site latitude, the launch site passes through the plane of that orbit twice a day, giving you two chances each day to launch into it -- typically with about a five-minute window on either side of the transit instant, depending on payload mass. (You tweak the azimuth to correct for slight out-of-plane errors, requiring additional fuel that eats into your margin.) For planetary missions the launch window is very narrow because the desired transfer orbit is sun-fixed and requires the Earth both to pass through it and to orient the launch site appropriately. You don't get a second chance to hit the same transfer orbit. It's not uncommon to have singular launch windows only seconds long. At the other end you have geostationary missions whose launch windows are constrained typically by whether the spacecraft is launched directly into a geostationary transfer orbit (GTO) or first into a LEO parking orbit, where the spacecraft is expected to be visible to private tracking stations for key maneuvers such as GTI (geostationary transfer injection). Direct-to-GTO missions have narrower windows since you need to hit a geodetic longitude. But you can loop in GTO several times, if necessary, so you get your two launch windows a day since the position of the spacecraft along its GTO doesn't have to coincide immediately at launch with the spacecraft's arrival at its final geostationary station. Typically you can piddle around for a while before the apogee boost maneuver. The first transfer maneuver can occur as quickly as 10 minutes after spacecraft separation, and the subsequent ABM burns occur typically beginning at T+130 hours and extending for as long into the mission as control confidence prevails. You have broader windows when LEO parking orbits occur, because you have the ability to fudge the GTI significantly, meaning the right ascension of the parking orbit is less important. Practical circumstances surrounding launch from Florida include staging constraints as well as contingency end-of-mission plans (a polite way of describing launch vehicle failure). You can't launch the space shuttle on southward-deflected azimuths, for example, because the ET might fall on populated areas. Only northward-deflected azimuths are allowed, so that the ET falls in the Indian Ocean. Other launch vehicles and mission profiles have similar range-safety constraints, minimizing the risk of intentional or unintentional debris fall over populations. These reduce or eliminate the launch windows that orbital mechanics dictate.
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Post by ka9q on Apr 5, 2010 19:19:27 GMT -4
Suboptimum trajectories are common on flights out of Vandenberg because of the need to avoid certain offshore oil platforms. The launcher may steer a dogleg, or hold onto its spent SRBs longer than usual.
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Post by Ginnie on Jul 18, 2010 17:03:15 GMT -4
I had an interesting conversation sitting with friends around the campfire last night. One lady, said to me, "For instance, I don't know if I believe that men landed on the moon?" I said, "Why not?" "Well, the shadows." "What about the shadows" "I don't know, there's something about the shadows..." Another gentleman there overheard us, and happily joined in. Clearly interested. Yes, he was a HB too. So he brought up some points - the cameras used on the missions, why we haven't been back since, the radiation belts . I answered all reasonably and logically, but you could tell the answers did not satisfy him or convince him of anything. He said to me, "okay, I'll give you half a point." I said, "I want a whole point!" ... and grudgingly he did, but then quickly switched the topic to JFK and RFK conspiracies, then 9/11, 2012, then the Gulf of Tonkin episode. It was just interesting that he believed in so many conspiracy theories. I knew that anything I could say contrary to his "beliefs" would not be considered. BTW the guy otherwise is very sensible and seemingly intelligent.
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Post by LunarOrbit on Jul 18, 2010 18:21:07 GMT -4
Sometimes you might as well be speaking a different language because nothing you say will sink into the HB mind. They believe what they want and nothing you say will change it.
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Post by Count Zero on Jul 18, 2010 20:45:40 GMT -4
That reminds me of a conversation I had, a while back, when I mentioned to a co-worker that I'd been in the military, and had worked at the Naval Intelligence Center. Intrigued, he asked if I knew the truth about alien visitors.
"Yes," I replied. "What is it?!" "You won't believe me." "Seriously?" "Absolutely" "Can you talk about it?" "Yes, but it won't do any good." "Why?" "You won't believe me if I told you." "I can believe a lot." ". . . " "Come on!" "There's no point." "I'll believe you." "Really?" "I promise. Tell me." . . . "They're not there."
He didn't believe me.
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Post by PeterB on Jul 19, 2010 8:26:34 GMT -4
Count Zero said: Awesome!
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Post by echnaton on Jul 19, 2010 9:25:38 GMT -4
That's just plain evil.
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Jul 5, 2011 21:29:02 GMT -4
I'm bumping this thread for drewid. Over a year ago you gave me permission to add your Apollo TLI animations to my web page, however I never got around to it. I'd like to get that done now but I need your help. I've started a web page but so far all I've done is embed the videos (see link below). I'd like to include some text to go along with it to explain what the animations are and how they came to be. Do you want to write something or do you prefer I wing it? Also, do you want me to credit you by your real name? If you want to write your own text, just post it in this thread or PM it to me. I'll then add it to the web page. Thanks. www.braeunig.us/apollo/TLI-animation.htm
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Post by fattydash on Jul 6, 2011 12:38:10 GMT -4
Radiation flares are very much unpredictable. My views as regards the best evidence proving Apollo's fraudulence have to do more with character assessment in a sense, demonstrating that principals such as Charles Berry, the astronauts themselves and others, are acting.
That said, as a physician with some day to day exposure as regards radiation concerns, the data I have seen addressing this issue, including van Allen's original Scientific American paper from 1959(applies mostly to belt concerns) is sobering.
It may well be that early on in all of this, it was determined that the radiation concerns simply could not be countenanced. They may have decided to fake the whole thing simply based on this risk.
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