Not a conspiracy question. If I should be posting these sorts of questions in general astronomy or somewhere else, please let me know. It's Apollo related so I am posting it here.

My question: What was the rate of fuel consumption in the Saturn V rocket between the earth and the moon.

Is there a good site that gives these details that I can refer to.

Thanks in advance.

John

Well this one doesn't really have a simple answer since only a small chunk of the S-V stack went all the way to the moon. Part of the S-IVB stage was used for Trans Lunar Injection (Please correct me if I am wrong here gang) and was discarded so the C/SM LM stack could then go the rest of the way. In any case, the rockets weren't firing continuously, only enough to get them going towards the moon, then for course correction maneuvers and the Lunar Orbit Insertion burn. So for which object and point of flight do you mean?

More numbers about Apollo than you can digest can be found in Richard Orloff's Apollo by the Numbers.
Another nice site is John Duncan's Apollo Saturn Reference Page.

HTH

Harald

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"Flying in space is risky business, but just staying on this planet is risky business too." - John Young, astronaut

The Saturn stack was staged, so that as each stage used it's fuel it could be discarded to save weight. The first two stages and part of the fuel in the third stage (the S-IVB) were used to get into a parking Earth orbit. After a checkout of systems, the third stage was re-ignited to send the stack toward the moon (a Trans-Lunar Injection, or TLI).

After the TLI, the Command & Service modules disengaged from the S-IVB and performed a manoeuvre to dock with the Lunar Module, which was stored in a special adaptor atop the S-IVB. The CM/SM/LM stack then simply coasted to the moon (the TLC), effectively unpowered except for some minor mid-course corrections.

Your question seems to indicate that you think the whole Saturn-V launch vehicle went to the moon, but this was not the case!

(By the way RP2/LOX consumption at launch for the 5-F1 engines combined was close to 15 tons per second! Mighty, mighty, awe-inspiring machines!)

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"I'd take the awe of understanding over the awe of ignorance any day." - Douglas Adams

I just finished "Lost Moon" by Jim Lovell and it wasn't until I read this book that I knew that the last stage of the Saturn V crashed into the moon. Was this the case on all the missions or only on some of them?

Also, how far behind the CM/LM/SM was the last stage? In other words, how long after lunar orbit was acheived did the final stage hit the moon?


Another question. I know that most of the Apollo mission were in a free-return trajectory. Which I believe means that if they didn't slow down to enter lunar orbit they would swing around it and be back on course for the Earth. Why wasn't the final stage of the Saturn V in this free-return trajectory as well?

Final question (I promise). Apollo 13 was a mission that wasn't on a free-return trajectory because of something to do with the location of their landing site, Fra Mauro (sp?). In the book Lost Moon the seismometers left by Apollo 12 picked up the final stage from Apollo 13 hitting the Moon. If they weren't in a free-return trajectory shouldn't the final stage have missed the moon?

Obviously I am ignorant of orbital mechanics and these questions popped into my head when I was reading the book. It still amazes me there are people smart enough to be able to calculate where to point a spacecraft, calculate a length of burn, and get the spacecraft where it needs to go.

The S-IVB was crashed onto the lunar surface for Apollos 13-17 inclusive.

They were on slightly diverging paths, so my understanding is that the CM/LM stack had entered lunar orbit at around the same time as the impact. The impact times for each S-IVB stage would be in Apollo By The Numbers.

The S-IVB had attitude control jets. After separation, these were fired to alter the trajectory of the S-IVB to a lunar impact one. This also ensured that there was no chance of the S-IVB interfering with the CM/LM stack during the TLC. During Apollo 13, there was a problem in that the telemetry from the S-IVB was on practically the same wavelength as the comm from Aquarius, causing communication problems.

See above. After separation, the trajectory of the S-IVB was altered.

[quote]Obviously I am ignorant of orbital mechanics and these questions popped into my head when I was reading the book.[quote]

These are very good questions.

And they did it all with slide rules, abacuses and pocket protectors!!


(edited to replace converging with diverging..... ops: )

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"I'd take the awe of understanding over the awe of ignorance any day." - Douglas Adams

Only Apollos 8, 10 and 11 were on free-return trajectory all the way until LOI. The spacecraft was put on the free-return trajectory from the TLI, but on other missions the midcourse correction burn put it on non-free-return trajectory. The purpose of this was to control the arrival time at the Moon to insure proper lighting conditions at the landing site.

And on the S-IVB APS burn from Apollo 13 Rewiev Board Report:

Didn't Apollo 15 fly a free return trajectory to LOI?

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Freedom For Fission A breath of fresh Iodine-131

Ah yes... J-missions didn't use this hybrid transfer manouver, but I'm not sure whether they were on a free-return trajectory or not, considering that their pericynthions were much lower than on missions that employed free-return trajectory. I'd guess no.

The free-return trajectory is a very small class of orbits. The hybrid trajectories used in Apollos 12-14 are "hybrid" because they start with the free-return trajectory established at TLI, then use one of the midcourse corrections to alter the trajectory in mid-coast, lowering the pericynthion of the orbit. A free-return trajectory has a very precise pericynthion and inclination, thus the reason for their being a small class of orbits.

Apollos 15-17 did not use hybrid trajectories, but neither did they use free-return trajectories. Their trajectories were not hybrids in the sense that no transfer manuever was performed midcourse. They were not free-return trajectories in the sense that in the failure of lunar orbit injection would not return the spacecraft to Earth. Further, especially Apollo 17's trajectory employed an inclination that resulted in a high inclination lunar orbit. This is necessary if you want to explore areas away from the lunar equator.

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Clavius Moon Base

Hmm, looking at the "Acknowledgements" page, a rather familiar looking name down in the third row from the bottom (as my browser renders it) just happened to catch my eye. Any relation?
P.S. While I'm at it, I should point out that as far as I know, the "Warren Owens" mentioned another couple of lines down is no relation to me, as far as I know.

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GhiaPet Home Page

Ha, saw it
An evil conspiracist in our midst. I'm very proud :wink:

Harald has also made some wonderful contributions to the ALSJ. Obvious disinfo agent! :wink:

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"I'd take the awe of understanding over the awe of ignorance any day." - Douglas Adams