Post by drewid on Sept 4, 2011 10:27:12 GMT -4
I've made a new thread for this as I don't want to take the other thread OT.
history.nasa.gov/SP-4029/Apollo_18-37_Selected_Mission_Weights.htm
As you probably know, the CM/LM was pressurized to just 5 psi. I don't know the exact size of the docking tunnel, but it was about 30 inches diameter. This means the force pushing on the LM was about 3500 lbf, which was enough to give it an initial acceleration of about 3.3 ft/s2. Of course, as soon as the vehicles undocked, that pressure was very quickly relieved; therefore, the duration the LM was subjected to any kind of a push was only a fraction of a second. I doubt the LM received even 1 ft/s delta-v as a result of the tunnel pressure. At the time of CSM-LM separation, the CSM's mass was only about a ton more than the LM, therefore it received just slightly less delta-v in the opposite direction.
That's just what I'm looking for. CSM at Separation for Lunar Landing 37,076.8 lbs LM at Separation for Lunar Landing
33,683.5 lbs. I'm sort of surprised they're as close in mass as they are but there's a lot of CSM fuel been burnt and a couple of astronauts moved from CSM to LM.
It's interesting that you come up with 1fps. I've seen that in one of the docs. I've read through so much in the last couple of weeks that i'm having trouble keeping it straight just where I saw it. I thought it might be the mission report, or ALSJ but looking through now I've not been able to spot it.
What I'm looking for is something that makes sense of the Reed quote. Now there's already a 21000 foot uprange error noted in the mission report, if the csm is also running a little slow that might explain the extra. Presumably the instrument error would be being corrected regularly, but even so...
Of course the Reed measurement is the only one that measures the relative positions of the CSM and LM. I'm wondering of that Reed quote came just before they realised about the uprange error. It's also interesting that the landing radar position and the photography(geologists) position match so well.
The following should give you what you want regarding weights of various components at various times:
history.nasa.gov/SP-4029/Apollo_18-37_Selected_Mission_Weights.htm
As you probably know, the CM/LM was pressurized to just 5 psi. I don't know the exact size of the docking tunnel, but it was about 30 inches diameter. This means the force pushing on the LM was about 3500 lbf, which was enough to give it an initial acceleration of about 3.3 ft/s2. Of course, as soon as the vehicles undocked, that pressure was very quickly relieved; therefore, the duration the LM was subjected to any kind of a push was only a fraction of a second. I doubt the LM received even 1 ft/s delta-v as a result of the tunnel pressure. At the time of CSM-LM separation, the CSM's mass was only about a ton more than the LM, therefore it received just slightly less delta-v in the opposite direction.
That's just what I'm looking for. CSM at Separation for Lunar Landing 37,076.8 lbs LM at Separation for Lunar Landing
33,683.5 lbs. I'm sort of surprised they're as close in mass as they are but there's a lot of CSM fuel been burnt and a couple of astronauts moved from CSM to LM.
It's interesting that you come up with 1fps. I've seen that in one of the docs. I've read through so much in the last couple of weeks that i'm having trouble keeping it straight just where I saw it. I thought it might be the mission report, or ALSJ but looking through now I've not been able to spot it.
What I'm looking for is something that makes sense of the Reed quote. Now there's already a 21000 foot uprange error noted in the mission report, if the csm is also running a little slow that might explain the extra. Presumably the instrument error would be being corrected regularly, but even so...
Of course the Reed measurement is the only one that measures the relative positions of the CSM and LM. I'm wondering of that Reed quote came just before they realised about the uprange error. It's also interesting that the landing radar position and the photography(geologists) position match so well.