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CincySpaceGeek
2003-Jun-27, 01:30 AM
Hey all!

Just joined the board after lurking for months, being an Apollo nut since childhood, and hearing a rehash of Bart Sibrel's drivel on "Coast To Coast AM". I've never had to chugalug a bottle of Pepto until last night. I come to this site to get a dose or realism.

Anyways, someone answer me an Apollo trajectory question: During a normal TLI and TEI, a course correction was done to clear the spacecraft from the spent S4B (on TLI), and the SM (on the return trip) before correcting to the proper trajectory heading. What happens to the S4B and SM after they're jettisoned? Do they just float off into deep space? Crash somewhere? Head off to ET's recycling bin? :wink:

Thanks for y'all's input!

Grand Vizier
2003-Jun-27, 02:05 AM
The Service Module is easy. They all re-entered the Earth's atmosphere on the way back.

The S-IVB bit is more complex. Most of them were deliberately crashed into the moon - which helped to calibrate the seismometers on the Apollo instrument packages. But the S-IVBs from Apollos 8,10,11 and 12 very likely ended up orbiting the sun. A recent Near Earth Object may have been one of these - probably from Apollo 12 - this is from when it was sighted:

http://science.nasa.gov/headlines/y2000/ast06nov_2.htm

Often forgotten is the Ascent Module of the LEM. Once again, most of the LEMs sent to the Moon (11-17) were deliberately crashed (well, 13 re-entered the Earth's atmosphere), but Apollo 10's LEM Ascent Module (Snoopy - or part of it) was sent off into solar orbit. Presumably it's still there.

And - if we really want to get train-spotterish - there are the four interstage panels attached to the S-IVB that protected the LEM during launch. There must be 32 of those in solar orbit, I reckon... :)

Glom
2003-Jun-27, 12:59 PM
Prior to Apollo 13, all trans-Lunar S-IVBs was deliberately moved, via controlled dumps of remaining propellants and from use of the APS, to a trajectory that would slingshot them into solar orbit.

CincySpaceGeek
2003-Jun-27, 02:09 PM
Is that a permanent solar orbit (circular or elliptical) or a "figure 8" (forgive my small astronomical vocabulary) where it endlessly does out-and-back trips between the Sun and the Moon? And if that's the case what keeps the S4B from impacting Earth on one pass?

Orbital mechanics is a wonderful thing. I just wish I understood it better.

Glom
2003-Jun-27, 02:19 PM
Is that a permanent solar orbit (circular or elliptical) or a "figure 8" (forgive my small astronomical vocabulary) where it endlessly does out-and-back trips between the Sun and the Moon?

No, it doesn't regularly return to Lunar orbit.


And if that's the case what keeps the S4B from impacting Earth on one pass?

An S-IVB is not that big. It would burn up in the atmosphere.

Grand Vizier
2003-Jun-27, 05:34 PM
Prior to Apollo 13, all trans-Lunar S-IVBs was deliberately moved, via controlled dumps of remaining propellants and from use of the APS, to a trajectory that would slingshot them into solar orbit.

Oops - forgot Apollo 13. But you know, I've never understood why they decided to put the Snoopy Ascent Stage into solar orbit. My best guess is that they wanted to see how long the engine would burn for in practice.

waynek
2003-Jun-27, 06:09 PM
Often forgotten is the Ascent Module of the LEM. Once again, most of the LEMs sent to the Moon (11-17) were deliberately crashed (well, 13 re-entered the Earth's atmosphere), but Apollo 10's LEM Ascent Module (Snoopy - or part of it) was sent off into solar orbit. Presumably it's still there.

I'm glad I found this thread. Sorry to interject fiction into GA, but I've been wondering about this very thing ever since I recently saw the pilot Futurama. When they take shelter in a LM from the Lunar night, my first thought was "hey, there should only be the lower half still there." Later, though, there was a plaque shown that said something about "replaced by yada yada". That's when I started wondering if any of the original flown accent modules were still around to have been repatriated with it's decent section. I guess if Snoopy were ever recovered, though, there still wouldn't be a match since IIRC the decent module was jetesoned some distance from the lunar surface and must have had a pretty rough landing. Similarly, there must not be much left of the accent stages that crashed. Too bad there's not a complete set of hardware for future generations to reassemble, I guess they'll be stuck with a missmatch or a mockup. :o

Grand Vizier
2003-Jun-27, 06:21 PM
I'm glad I found this thread. Sorry to interject fiction into GA, but I've been wondering about this very thing ever since I recently saw the pilot Futurama. When they take shelter in a LM from the Lunar night, my first thought was "hey, there should only be the lower half still there." Later, though, there was a plaque shown that said something about "replaced by yada yada".

We're both very sad people. I saw that one and I had the very same thought. Time for a very sad 'BA in Futurama' thread over on the Bad TV area...



That's when I started wondering if any of the original flown accent modules were still around to have been repatriated with it's decent section. I guess if Snoopy were ever recovered, though, there still wouldn't be a match since IIRC the decent module was jetesoned some distance from the lunar surface and must have had a pretty rough landing. Similarly, there must not be much left of the accent stages that crashed. Too bad there's not a complete set of hardware for future generations to reassemble, I guess they'll be stuck with a missmatch or a mockup. :o

Well, I'll probably be shot down for this, but I'd guess that the ascent stage would be more standard than the descent (because the latter had to accomodate lunar rovers, heavier ALSEPs etc later on). But even so, I'd imagine that if you have the wealth and technology to recover Snoopy, you'd be able to mate it to, say, the Apollo 17 descent module easy enough. The main couplings won't have changed that much if at all - and after all, it only has to sit there - not actually work.