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kryton
2007-Mar-07, 06:21 PM
Where in the Apollo command module did they store the lunar rocks and soil samples? On diagrams I've looked at, they don't show lunar sample storage areas. Also, is there any literature on this procedure? On Apollo 17, they had 245 lbs of lunar samples to store for reentry. Also, the center of mass for the reentry module was offset 1 ft. for reentry purposes. Wouldn't 245 lbs of rocks negate this critical design factor?

NEOWatcher
2007-Mar-07, 06:34 PM
Where in the Apollo command module did they store the lunar rocks and soil samples? ...
I don't have an answer, but here's what I assume:
From a page on modifications to apollo: this diagram (http://www.hq.nasa.gov/office/pao/History/diagrams/astp/bp226b.htm) points to the area at the base of the capsule for stowage area.
And looking at the CM diagram here (http://history.nasa.gov/diagrams/apollo.html) there seems to be a compartment next to the CO2 Absorber storage.

Occam
2007-Mar-07, 06:54 PM
Yes, it was possible to stow quite a bit behind the seats.
BTW - here's an interesting Japanese site with a lot of original info
http://apollomaniacs.web.infoseek.co.jp/apollo/indexe.htm

Svector
2007-Mar-07, 07:05 PM
Where in the Apollo command module did they store the lunar rocks and soil samples? On diagrams I've looked at, they don't show lunar sample storage areas. Also, is there any literature on this procedure? On Apollo 17, they had 245 lbs of lunar samples to store for reentry. Also, the center of mass for the reentry module was offset 1 ft. for reentry purposes. Wouldn't 245 lbs of rocks negate this critical design factor?

They were locked in vacuum sealed boxes and wrapped up in some kind of fiberglass sealant, then placed in storage compartments inside the LM's lower panels.

As for the CM, I'm not sure where they were kept after transfer from the LM. Maybe Jay or sts60 know.

JayUtah
2007-Mar-07, 07:33 PM
The wrapped SRCs went in lockers B5 and B6 in the following diagram.
http://history.nasa.gov/ap16fj/02stowage.htm

For the benefit of those for whom this diagram isn't quite clear, those are just under the navigation station in the Lower Equipment Bay.

When the center of mass is computed for the flight dynamics of re-entry, the computation accounts for the spacecraft and its contents at that time.

Donnie B.
2007-Mar-07, 10:07 PM
As I recall, the Apollo 13 crew had to do some "spring cleaning" because they didn't have the lunar samples they were planned to have. They reorganized the storage to ensure the proper mass distribution on reentry. That included bringing some items from the LM that would normally have been jettisoned along with the ascent stage before EOI.

JayUtah
2007-Mar-07, 10:12 PM
As I recall, the Apollo 13 crew had to do some "spring cleaning"...

Correct. The Apollo 13 CM had to be ballasted to achieve acceptable re-entry flight dynamics. The ballast was would-be jetsam from the LM which was stowed in the B5 and B6 lockers.

kryton
2007-Mar-07, 10:30 PM
How did they determine the weight of the moon samples in a weightless environment to be able to compute and correct for the center of mass at the time?

Donnie B.
2007-Mar-07, 10:45 PM
They knew how much lunar material they expected to bring back. They knew the mass of the various objects from the LM. They added those masses until they approximated the mass of the expected samples. Voila.

Rue
2007-Mar-07, 10:46 PM
^Going to assume the samples were weighed on the moon first.

JayUtah
2007-Mar-07, 10:47 PM
How did they determine the weight of the moon samples in a weightless environment...

For Apollo 11 they weighed them on the Moon before they loaded them. Then based on observing Apollo 11's inbound flight path, they determined that it wasn't necessary to know the mass of the samples with that much precision, so they just estimated it for later missions.

Kelfazin
2007-Mar-07, 10:50 PM
How did they determine the weight of the moon samples in a weightless environment to be able to compute and correct for the center of mass at the time?

They had a scale onboard the LM. They weighed the samples while still on the luanr surface and then did the math to figure earth weight.

From the Apollo Lunar Surface Journal, A17, end of EVA 1

125:15:50 Cernan: And the SRC is 32 pounds.

125:15:56 Allen: Copy; 32 pounds.

[Comm Break.The crew has a small spring scale which gives them terrestrial weights. That is, on Earth, a two-pound (Earth-weight) rock would register twelve pounds on the scale while, on the Moon, it would register two pounds. The actual weight of rocks collected during this EVA is given in the Mission Report as 31 pounds (14 kg). The 48-pound (21.8 kg) total given here includes the weights of the individual sample bags, the two 1.7 pound (0.8 kg) SCBs, and the 14.7 pound (6.7 kg) SRC. Weights are measured so that the flight engineers can adjust the stowage for center-of-mass control, if necessary

JayUtah
2007-Mar-07, 10:55 PM
It should be understood that the lunar samples are only one of several stowage and consumable factors that affected the CM center of mass. You don't have to know the center of mass right down to the inch. It's not rocket science. In fact, it's airplane science. You have to know an aircraft's center of mass too, and so part of any pilot's training is the methods for doing that. You don't have to know where it is exactly. You just have to make sure it's inside the envelope for which the vehicle can maintain aerodynamic stability.

captain swoop
2007-Mar-07, 11:11 PM
The answers in this thread are the reason I love this site!

Donnie B.
2007-Mar-07, 11:12 PM
I think I may have misinterpreted kryton's question above, so my answer may have seemed a little flip.

I thought he was asking how they could tell when they had provided enough alternate ballast. It seems that he was really asking about how they knew how much the lunar samples massed, which others have answered in detail.

Assuming Jay is right about the flexibility of the numbers, a scale seems like overkill. Rocks are all pretty close to the same density; it seems that "fill these two lockers with assorted samples" would get you in the ballpark. I guess it all depends on how big that envelope is.

BigDon
2007-Mar-07, 11:46 PM
The answers in this thread are the reason I love this site!


I so totally am in agreement with you.

JayUtah
2007-Mar-08, 12:17 AM
Assuming Jay is right about the flexibility of the numbers, a scale seems like overkill.

Only in hindsight. The rules of human-rated engineering take little for granted, even the most confident estimates. Measuring the effect of moon rocks on the re-entry dynamics (even to confirm a suspicon) is far preferable.

Rocks are all pretty close to the same density...

But no one knew for sure until Apollo 11 how dense moon rocks would be, although there were some estimates that turned out to be accurate. Better to measure once at first to confirm that it doesn't matter that much. Engineers are just like that.

I guess it all depends on how big that envelope is.

Any departure from the ideal requires some sort of trim in order to restore dynamic equilibrium. You exceed the envelope when you exceed the capacity of your trim mechanism, but with every bit of control required to maintain straight and level flight you lose a bit of control for commanding flight manuevers or correcting for other instability factors (e.g., wind gusts). It's a fuzzy-edged envelope.

In the final analysis, 200 pounds of moon rocks have a measurable effect on a 12,000 spacecraft, but not enough to dominate the solution. Saying that the placement and mass of the moon rocks has to be just right is the tail wagging the dog.

BigDon
2007-Mar-09, 12:21 AM
A side trip on the subject of weight and trim.

There was this piece of ECM gear on the Tomcat called the ALQ 100. The box for it was about 200lbs. Since you don't really need ECM in the US whenever the pilots were going crosscountry to the East coast we would pull the boxes (It broke down to two pieces) so they could carry extra luggage.

Once, two of our birds went to Maine for an airshow and a guy in our shop's people were lobstermen so when they came back, both the ALQ bays were loaded with live lobsters. Which, surprizingly enough, survived. Well, at least until that evening. (Yes, they were in boxes, not loose)

captain swoop
2007-Mar-09, 01:33 AM
my cousin flew as the nav in buckaneers. when they flew down to cyprus for exercises they would always pack hte rotating bomb bay (keeps things nice and slick!) with duty free spirits and tobacco for the journey home and dump the 'personal effects'

sts60
2007-Mar-09, 03:42 PM
In his book Bombs Awry! (http://www.amazon.com/Bombs-Awry-Grover-Ted-Tate/dp/0892880937/ref=sr_1_2/102-1324056-3648147?ie=UTF8&s=books&qid=1173454115&sr=8-2), Grover Ted Tate, who as a contractor and Air Force flyer had a hand in the development and test of many famous aircraft, relates bringing back an MG in the wing root of a B-36. I love that book.

To go back on-topic, it will be interesting to see how the stowage provisions for Orion evolve.

Sigma_Orionis
2007-Mar-09, 05:12 PM
My question is a bit off topic, but I'd like to know why there are referred to as Stowage instead of Storage? sometimes my English gets in the way... :D

NEOWatcher
2007-Mar-09, 05:31 PM
My question is a bit off topic, but I'd like to know why there are referred to as Stowage instead of Storage? sometimes my English gets in the way... :D
To store is more to put away for safekeeping. While to stow is to pack away for transportation.

Kelfazin
2007-Mar-09, 05:35 PM
My question is a bit off topic, but I'd like to know why there are referred to as Stowage instead of Storage? sometimes my English gets in the way... :D


Also, stow is the nautical term for store.

Stow [stoh]
-verb (used with object)
1.Nautical. a.to put (cargo, provisions, etc.) in the places intended for them. b.to put (sails, spars, gear, etc.) in the proper place or condition when not in use.

JayUtah
2007-Mar-09, 05:41 PM
Aerospace borrows many nautical terms. Boeing's drawings for cabin layouts etc. still refer to stowage.

Sigma_Orionis
2007-Mar-09, 06:08 PM
Thank you all, and incidentally: Yes, I have noticed that in "B" passenger aircraft the term used is "stowage".

You guys just answered a question that has been lingering around me for close to 20 years :)