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#21
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Henry Spencer wrote: There was probably a spec somewhere for how big a fall the LM was expected to survive with the ascent stage still intact... but I don't know what it was, offhand. Given the rather lightweight construction, I'm sure it was meters, not tens of meters. According to this, 3.05 MPS vertical velocity and 1.22 MPS horizontal velocity; but what Grolsch beer glass design has to do with this all is a bit beyond me: http://dutlsisa.lr.tudelft.nl/Vehicl...ng/Landing.pdf .....although I applaud the concept of using beer as a teaching aid, and I assume the guy driving the car into the tree has had one too many Grolschs. :-D Pat |
#22
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In article ,
Pat Flannery wrote: There was probably a spec somewhere for how big a fall the LM was expected to survive with the ascent stage still intact... but I don't know what it was, offhand. Given the rather lightweight construction, I'm sure it was meters, not tens of meters. According to this, 3.05 MPS vertical velocity and 1.22 MPS horizontal velocity... Hmm, at a surface gravity of 1.62m/s^2, assuming engine failure at zero vertical velocity, that's a 2.9m drop. Of course, that's probably the maximum for an undamaged landing on a worst-case surface (solid rock), after safety margins. The normal surface isn't *quite* that hard, and if you're going to leave immediately, you don't care how much of the descent stage gets crushed so long as the ascent stage is intact. If it's a clean vertical drop onto a reasonably flat surface, 5-10m might well be okay. -- "Think outside the box -- the box isn't our friend." | Henry Spencer -- George Herbert | |
#23
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Henry Spencer wrote: Hmm, at a surface gravity of 1.62m/s^2, assuming engine failure at zero vertical velocity, that's a 2.9m drop. They also might have figured that it could come down at an angle so that one leg took the brunt of the initial impact. Of course, that's probably the maximum for an undamaged landing on a worst-case surface (solid rock), after safety margins. The normal surface isn't *quite* that hard, and if you're going to leave immediately, you don't care how much of the descent stage gets crushed so long as the ascent stage is intact. If it's due to motor failure rather than propellant depletion, there are those crushed fuel and oxidizer tanks to contend with- you might lift off again immediatly....via a big explosion in the descent stage. If it's a clean vertical drop onto a reasonably flat surface, 5-10m might well be okay. Where is that legendarily tough Grumman landing gear? ;-) Pat |
#24
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In article ,
Pat Flannery wrote: ...The normal surface isn't *quite* that hard, and if you're going to leave immediately, you don't care how much of the descent stage gets crushed so long as the ascent stage is intact. If it's due to motor failure rather than propellant depletion, there are those crushed fuel and oxidizer tanks to contend with- you might lift off again immediatly....via a big explosion in the descent stage. You don't normally get a major explosion out of hypergolics. Although, of course, it wouldn't take that much to damage something as fragile as the ascent stage. -- "Think outside the box -- the box isn't our friend." | Henry Spencer -- George Herbert | |
#25
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You don't normally get a major explosion out of hypergolics. Although, of course, it wouldn't take that much to damage something as fragile as the ascent stage. -- Ahh the big problem would be coming down out of level by say partially hitting a boulder ior one leg in a crater. too far off level and you cant take off but I forget the angle... HAVE A GREAT DAY! |
#26
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You are absolutely correct. I just wish folks would do their homework by
reading reputable history books. Both Stafford and Cernan have witten about the incident on Apollo 10. Matthew Ota Jay Windley wrote: "Jonathan Silverlight" wrote in message ... | | They got into a spin and nearly crashed. But that was because a guidance system switch had been set improperly, not because the separation induced the spin. There is always a danger aborting at low altitudes, and I'm sure the astronauts, as seasoned test pilots, were well aware of what their options were. |
#27
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"Matthew Ota" wrote in message ... | | You are absolutely correct. I just wish folks would do their homework by | reading reputable history books. Both Stafford and Cernan have witten | about the incident on Apollo 10. It's a great story, not just because of the inherent drama but because of some of the things that arose in its aftermath. Cernan yelled, "Sonuvabitch!" over the A/G loop when it happened. Understandable, given the circumstance. Most pilots get a little put out when their craft tries to align itself to an imaginary (and wrong) notion of "up". Of course the blue-crested religious types descended on NASA and demanded St. Eugene be reprimanded. According to Cernan that incident actually softened NASA's stance on vulgarity over the airwaves. You can only expect pilots not to be pilots to some extent. When you go back and talk to Cernan and Stafford and try to understand what happened, they tell you that each man flipped the switch to select the guidance mode. Neither pilot *looked* at the switch; the checklist said to select a certain mode, and because of how the mission went, each pilot knew that in order to obey the checklist he would have to reverse the position of the switch to select that mode. So Stafford did it. And then Cernan did it too. Being able to operate a craft's controls without looking at them is a skill pilots have to develop. Anyway, when it came time for Cernan to be in the pilot's "seat" for Apollo 17, he tells of drawing a chalk line down the LM instrument panel. Every switch left of the line belonged to Cernan and everything to the right of it belonged to Schmitt. Woe betide the astronaut whose hand strayed across that line. Funny, and yet sensible. -- | The universe is not required to conform | Jay Windley to the expectations of the ignorant. | webmaster @ clavius.org |
#28
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In message , Jay Windley
writes "Matthew Ota" wrote in message ... | | You are absolutely correct. I just wish folks would do their homework by | reading reputable history books. Both Stafford and Cernan have witten | about the incident on Apollo 10. It's a great story, not just because of the inherent drama but because of some of the things that arose in its aftermath. Cernan yelled, "Sonuvabitch!" over the A/G loop when it happened. Understandable, given the circumstance. Most pilots get a little put out when their craft tries to align itself to an imaginary (and wrong) notion of "up". Of course the blue-crested religious types descended on NASA and demanded St. Eugene be reprimanded. According to Cernan that incident actually softened NASA's stance on vulgarity over the airwaves. You can only expect pilots not to be pilots to some extent. According to the transcript at http://www.jsc.nasa.gov/history/mission_trans/apollo10.htm there are 21 instances of "son of a bitch" in the LM transmissions. Makes sense when you're flying with Snoopy :-) |
#29
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On 2004-08-26, Jonathan Silverlight
wrote: According to the transcript at http://www.jsc.nasa.gov/history/mission_trans/apollo10.htm there are 21 instances of "son of a bitch" in the LM transmissions. Makes sense when you're flying with Snoopy :-) And they have the temerity to say the Internet isn't educational... -- -Andrew Gray |
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