# Two Apollo questions **URL:** \ **Category:** Factual Questions\ **Created:** [July 17, 2009, 2:30pm UTC](https://boards.straightdope.com/t/two-apollo-questions/503339 "2009-07-17T14:30:19Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![Ximenean](https://avatars.discourse-cdn.com/v4/letter/x/aca169/32.png) [@Ximenean](https://boards.straightdope.com/u/Ximenean)\ **Post date:** [July 17, 2009, 11:40pm UTC](https://boards.straightdope.com/t/two-apollo-questions/503339/21 "2009-07-17T23:40:37Z")
> [@CurtC](#): > > Nice diagram. It looks to me, from looking at that diagram, that going to the left of the Moon and orbiting it clockwise would help slow the spacecraft down. Had they approached from the right, it would have been like a classic gravity-assist which would use the Moon’s tug to speed the orbiter up. I don’t see how an orbiter can know which way the body it is orbiting is rotating, so I am sceptical of that explanation. I wasn’t aware that the sort of gravitational slingshots exploited by spacecraft had anything to do with the rotation of the objects that they slingshot around. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 18, 2009, 2:09am UTC](https://boards.straightdope.com/t/two-apollo-questions/503339/22 "2009-07-18T02:09:57Z")
Orbital direction, not rotational. Rotation is only relevant in GR, and that only slightly. ---
**Author:** ![ElvisL1ves](https://avatars.discourse-cdn.com/v4/letter/e/5daacb/32.png) [@ElvisL1ves](https://boards.straightdope.com/u/ElvisL1ves)\ **Post date:** [July 18, 2009, 3:23pm UTC](https://boards.straightdope.com/t/two-apollo-questions/503339/23 "2009-07-18T15:23:27Z")
> [@Dreamy\_B](#): > > The only advantage that I can think of is by docking the LM, this gives the astronauts a little more room to move about the cabin for the day or two it takes to reach the moon. I suppose this allows them to perform various house keeping chores on their way. And it gave plenty of time for LM systems checks and fixes before committing to landing - that was vital on Apollo 14, which almost had its landing scrubbed due to a balky docking mechanism. Another reason for doing it early is that it allowed for some separation from the S-IVB (the third stage booster). Remember that it had just as much velocity after TLI as the CM/SM/LM combination, and was headed for the moon too. Adding just a bit of delta-V with a bit of thrust got the manned package far enough away from the booster that it wouldn’t be a factor in lunar maneuvering. In fact, the Apollo 13 and later S-IVB’s were intentionally crashed onto the lunar surface as part of controlled seismology experiments (the seismometers had been placed by earlier missions). Earlier ones are all in solar orbit, and one was even “discovered” as an asteroid. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [July 18, 2009, 3:32pm UTC](https://boards.straightdope.com/t/two-apollo-questions/503339/24 "2009-07-18T15:32:36Z")
> [@ElvisL1ves](#): > > Earlier ones are all in solar orbit… I’ve wondered about those (and the LMs) since watching an episode of Gerry Anderson’s _UFO_ when I was a kid, which featured an S-IVB that (IIRC) the aliens were using as cover when coming to Earth. Where can I read more about the disposition of the S-IVBs (and LMs)? ---
**Author:** ![Terminus\_Est](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/terminus_est/32/3087_2.png) [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)\ **Post date:** [July 18, 2009, 3:34pm UTC](https://boards.straightdope.com/t/two-apollo-questions/503339/25 "2009-07-18T15:34:51Z")
> [@Chronos](#): > > Orbital direction, not rotational. Rotation is only relevant in GR, and that only slightly. Yes, from the diagram I posted, it’s clear that, rather than wasting time and fuel chasing a moon moving away from them, they go around to the other side and let the moon come to the spacecraft. ---
**Author:** ![Cliffy](https://avatars.discourse-cdn.com/v4/letter/c/59ef9b/32.png) [@Cliffy](https://boards.straightdope.com/u/Cliffy)\ **Post date:** [July 18, 2009, 8:37pm UTC](https://boards.straightdope.com/t/two-apollo-questions/503339/26 "2009-07-18T20:37:21Z")
> [@Johnny\_L.A](#): > > Where can I read more about the disposition of the S-IVBs (and LMs)? Wikipedia has charts with all that stuff. [Here](http://en.wikipedia.org/wiki/S-IVB) is the page for the S-IVB’s. –Cliffy ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [July 18, 2009, 8:42pm UTC](https://boards.straightdope.com/t/two-apollo-questions/503339/27 "2009-07-18T20:42:00Z")
> [@Cliffy](#): > > Wikipedia has charts with all that stuff. [Here](http://en.wikipedia.org/wiki/S-IVB) is the page for the S-IVB’s. > > –Cliffy Thanks. Earlier I found a Wiki article on the LMs, and the ascent stage for Apollo X’s _Snoopy_ is in solar orbit. ---
**Author:** ![Icerigger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/icerigger/32/432_2.png) [@Icerigger](https://boards.straightdope.com/u/Icerigger)\ **Post date:** [July 18, 2009, 10:52pm UTC](https://boards.straightdope.com/t/two-apollo-questions/503339/28 "2009-07-18T22:52:51Z")
According to the Wiki articles and links there is 176 metric tons of man made equipment on the lunar surface! [Previous page](https://boards.straightdope.com/t/two-apollo-questions/503339.md?page=1)