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Post by Ginnie on Mar 6, 2010 21:32:05 GMT -4
Leonov reiterates: Don't know if this is old hat but, beginning @ 11:54, he gives his opinion on the lunar landing hoaxers. "That is ignorance, total ignorance on the part of those who say so. These people don't know anything about technology. Or they just seek popularity."Quoted from: RT.com rt.com/Top_News/2009-07-21/I_could_see_Armstrong_bouncing_on_the_moon.html?fullstory"I could see Armstrong bouncing on the moon"; Published 21 July, 2009, 22:51 expanded a bit.. RT: The US is often accused of not actually going to the moon and faking the images from there. What’s your take on that?
AL: That is ignorance, total ignorance on the part of those who say so. These people don't know anything about technology. Or they just seek popularity. Only two countries did not monitor the orbiting of the moon and landing on it. It was during the Cold War. There were systems, monitoring planes as well as rockets. Our radars monitored everything. We did not have a mission control center. There was a space communication military base in Moscow. Americans announced the start of Saturn-5 with Frank Borman as the commander. We observed the start of the rocket, Americans were transmitting it to the whole world, and only two countries were not watching – the Soviet Union and China. Out of stupidity. We saw all four adjustments. Our systems saw how a huge meteor came from the south and landed.
One interesting fact: Frank Borman came here some time after the flight. Crowds surrounded his hotel every day. The government held a great reception for him, there was a press conference. Our people greeted Frank Borman just like they had greeted Gagarin. It was pure joy!
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Post by hplasm on Mar 6, 2010 21:54:19 GMT -4
found an unattributed quote about it (Might be Schirra?) Ooo! Can anyone recommend a simulation where you could just do that sort of manoever over and over again, perhaps in different gravity fields? It would be enormous fun Oh- if that makes me sound geeky, I don't care. i could do that for ages! Also- anything but windows if possible. and Oh- if that makes me sounds more geeky I care less- More time to do orbital stuff, less time beating the computer with a mace (If I must, I could reanimate a worthless corpse to infect with XP)
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Post by echnaton on Mar 6, 2010 22:44:34 GMT -4
IIRC from reading How NASA Learned to Fly in Space, the first time a rendezvous was attempted it was a failure. One of the early Gemini launches turned after booster separation around to try to go back to the booster. They did the point and shoot maneuver and wasted fuel to move further from the booster. They were quite surprised. It seemed that no one had given much thought on the matter. It woke NASA up and they figured it all out pretty soon.
Later successes were made by coming in under the target and using the ranging computer or sextant to get bearings for small burns that synchronized the orbits with the crafts together.
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Post by drewid on Mar 7, 2010 3:57:53 GMT -4
Just in case someone else comes along and likes the broken "boat in an ocean" analogy...
No it's more like this.
The boat isn't in an ocean it's on the beach of an island. The island is in a known position. The boat has has optical navigation instruments, inertial navigation systems and a computer with a built in autopilot, and programmes designed for solving navigation problems. The original planned landing spot had some rocks so they cruised east at a speed of 10 knots for exactly six minutes to find a better spot, so they know precisely where they are on the island.
With the boat is a bigger cruiser, the cruiser is circling the island at a precisely know distance and speed. The cruiser also has all the navigation gizmos, the boat and the cruiser see each other several times a day as the cruiser goes past, and both the boat and the cruiser are in constant radio contact with the mainland.
On the mainland is a building full of people who are expert at location and navigation problems, they have big computers programmed to give them the precise time when the boat will have to leave the beach to meet up with the cruiser while using the minimum fuel. They can send this information to the guy in the boat who can program it into his autopilot.
See?
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Post by scooter on Mar 7, 2010 11:46:24 GMT -4
found an unattributed quote about it (Might be Schirra?) Ooo! Can anyone recommend a simulation where you could just do that sort of manoever over and over again, perhaps in different gravity fields? It would be enormous fun Oh- if that makes me sound geeky, I don't care. i could do that for ages! Also- anything but windows if possible. and Oh- if that makes me sounds more geeky I care less- More time to do orbital stuff, less time beating the computer with a mace (If I must, I could reanimate a worthless corpse to infect with XP) Well, there's "Orbiter"...but it's Windows (but the best WIN program out there). It's great fun to take the Saturn V to put the CSM into geostationary orbit! Or chase down the ISS with the Shuttle. It works very well at this end.
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Mar 7, 2010 13:20:09 GMT -4
Sadly blackbriar1 seems to have run away screaming from the prospect of actually learning something. Nonetheless, I’d like to comment on the following: How they going to be able to link up, get into the same plane of orbit and have all this extra fuel on board the LEM to catch up and dock up with the Service Module? Blackbriar1 seemed to imply that launching the LM into the same orbital plane as the CSM was a problem because the LM landed off target and we didn’t know exactly where it was. What blackbriar1 neglected to recognize is that the LM landed long of is target, not wide. The CSM, the targeted landing spot, and the actually spot were all within the same plane. After nearly a day on the lunar surface, the nodes of the CSM orbit would have progressed slightly, and the moon would have rotated beneath the CSM’s orbit, but these movements would be known precisely. All the CSM had to do was perform a small plane change to adjust the location of the nodes and bring the orbital plane back into alignment with the planned landing site, and consequently, the actual landing site. All the LM then had to do is to takeoff along the same heading that it landed and it was precisely in the orbital plane of the CSM. The only thing landing long would do is change the timing by about one second for every mile off target. How far off target the LM landed could be reasonably estimated, and besides, it really doesn’t matter when using a co-elliptic rendezvous technique. It just means that the time it takes the LM to catch up to the CSM may be off by a few seconds. Initiation of the final maneuver (terminal phase) was based on actual radar measurements. If there was any error in the timing and/or relative position of the spacecraft, it was easily fixed in the calculation of the final maneuvers.
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Post by chew on Mar 7, 2010 14:15:44 GMT -4
One question about the LM lifting off. How did they time it? I know Houston did most of the math and relayed info to the astronauts, but did the LM AGC compute the time to lift off based on the CSM's orbit or was the time to lift off relayed to the LM?
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Mar 7, 2010 14:50:37 GMT -4
One question about the LM lifting off. How did they time it? I know Houston did most of the math and relayed info to the astronauts, but did the LM AGC compute the time to lift off based on the CSM's orbit or was the time to lift off relayed to the LM? I don't know for sure, but my guess would be that the time was determined on the ground, relayed to the astronauts, and then entered into the LM computer.
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Post by hplasm on Mar 7, 2010 15:58:51 GMT -4
Well, there's "Orbiter"...but it's Windows (but the best WIN program out there). It's great fun to take the Saturn V to put the CSM into geostationary orbit! Or chase down the ISS with the Shuttle. It works very well at this end. Hmm, yes, i had considered Orbiter at one time, but I never got around to trying it out; what I had in mind was a simpler thing, like the old DOS Lunar Lander where the input is all numeric... aha- might be an idea there- that should keep me happy, if I can still find it. Thanks Scooter
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Mar 7, 2010 16:55:26 GMT -4
The co-elliptic rendezvous was developed and practiced during the Gemini missions. The technique was then used for Apollo 11. The following are some excerpts from the book How NASA Learned To Fly In Space by David M. Harland describing the technique as it was used during Gemini. By the time of Apollo 11, orbital rendezvous had been well practiced and perfected. The procedures were, of course, modified for lunar orbit. The rendezvous was preformed in a little over three hours, or 1-1/2 orbits. The velocity changes for the various maneuvers were small because, as chew pointed out earlier, the velocities in lunar orbit are about 20% what they are in Earth orbit. The Apollo 11 maneuvers are summarized below: Maneuver | GET | Burn Time (s) | Delta-V (ft/s) | Apolune (n.mi.) | Perilune (n.mi.) | Ascent | 124:22:00.0 | 439.9 | 6070.1 | 45.2 | 9.0 | Coelliptic Sequence Initiate | 125:19:34.7 | 47.0 | 51.5 | 48.6 | 45.3 | LM Plane Change | Not Performed | N.P. | N.P. | N.P. | N.P. | Constant Delta Altitude | 126:17:46.0 | 18.1 | 19.9 | 47.0 | 40.9 | Terminal Phase Initiate | 127:03:30.8 | 22.8 | 25.3 | 61.2 | 43.9 | Terminal Phase Finalize | 127:45:54.0 | 28.4 | 31.4 | 62.2 | 56.6 |
Other than ‘Ascent’, all of the above maneuvers were performed using the RCS thrusters. We can see the total RCS delta-V was 128.1 ft/s. The mass of the LM ascent stage at orbit insertion was 5,928.6 lbm. Knowing that the RCS thrusters had a specific impulse of 290 seconds, we can calculate the propellant consumption using Tsiolkovsky's rocket equation: Mf = Mo*e^-(dV/C) Mf = 5928.6*2.71828^-(128.1/(290*32.174)) Mf = 5847.8 lbm Propellant used = Mo – Mf = 5928.6 – 5847.8 = 80.8 lbm This is only about 15% of the RCS propellant load.
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Post by slang on Mar 7, 2010 18:14:17 GMT -4
Sadly blackbriar1 seems to have run away[..] I knew I heard that name before... Just watched The Bourne Ultimatum (again). Surely people can be just a little bit more creative when thinking of a board name to post conspiracies?
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Post by chew on Mar 7, 2010 18:20:58 GMT -4
Beautiful! I could read stuff like this all day. I didn't know all the Geminis had to do was pitch up xx degrees and wait for the target to be straight ahead to initiate the rendizvous. That is too cool. I wonder how many millions and millions of megabytes it takes to make a spacecraft pitch up? Because everybody knows computers back then had less computing power than modern calculators.
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Post by Count Zero on Mar 8, 2010 3:48:53 GMT -4
Of course, Soyuz flew for 20 years before the Soviets equipped it with an onboard computer. During that time it made several dozen successful orbital rendezvous with each other and with the various Salyut & Mir space stations.
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Post by tedward on Mar 8, 2010 6:42:32 GMT -4
With reference to calculators being better etc etc (the claim by the OP earlier). I was looking at the Babbage machine the science museum and marveling at its complexity but also what it was aimed at. Working out tables, but only after his death was it shown to work. In the same museum are several interesting devices including a differential Analyzer (I think that is what it was) made of Meccano. All of these strike me a made to order, to do one job or a limited type of work, along with the bombe used on enigma and on to guidance stuff on Apollo. The nubbin of my niggles with these claims of pocket calculators or car ECU being more powerful etc.
All of these people can say their calculator is more powerful, how many can show it? How many know how a calculator actually works and could work out what Apollo required to do its job?
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Post by ka9q on Mar 8, 2010 9:29:49 GMT -4
Blackbriar1 seemed to imply that launching the LM into the same orbital plane as the CSM was a problem because the LM landed off target and we didn’t know exactly where it was. Did anybody mention to our friend that the LM and CSM weren't exactly flying blind? That they had two independent ways to determine their relative positions and velocities in addition to ground-based S-band ranging and Doppler for each spacecraft? (That would be the LM's rendezvous radar and the CSM's VHF ranging system.) And for most of the missions the resulting plane change was very small, not only because of the moon's slow rotation but because the early landings were made very close to the lunar equator from a lunar orbit with a very small inclination. Only after they got comfortable with a few of these did they increase the inclination of the lunar orbit to make it possible to reach higher latitudes. "High" was relative; the highest lunar latitude reached by any Apollo mission was only 26N (Apollo 15).
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