# What is bearing the weight of rocket on the pad? **URL:** \ **Category:** Factual Questions\ **Created:** [January 1, 2012, 11:43pm UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090 "2012-01-01T23:43:42Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![beeyule](https://avatars.discourse-cdn.com/v4/letter/b/6bbea6/32.png) [@beeyule](https://boards.straightdope.com/u/beeyule)\ **Post date:** [January 1, 2012, 11:43pm UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/1 "2012-01-01T23:43:42Z")
Fully fueled space shuttles, Apollo spacecraft, etc., seem simultaneously heavy and delicate. I’ve often wondered what part of the spacecraft, or what kind of apparatus is bearing this load when it is sitting on the pad. I’ve looked at several pictures but can’t see how this is accomplished. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [January 1, 2012, 11:50pm UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/2 "2012-01-01T23:50:43Z")
> [@beeyule](#): > > Fully fueled space shuttles, Apollo spacecraft, etc., seem simultaneously heavy and delicate. I’ve often wondered what part of the spacecraft, or what kind of apparatus is bearing this load when it is sitting on the pad. I’ve looked at several pictures but can’t see how this is accomplished. I believe it’s done by pressurizing the container. The older museum exhibits had to be pressurized to stand up on display. ---
**Author:** ![foolsguinea](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foolsguinea/32/14751_2.png) [@foolsguinea](https://boards.straightdope.com/u/foolsguinea)\ **Post date:** [January 1, 2012, 11:52pm UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/3 "2012-01-01T23:52:33Z")
Is that even an answer to this question? ---
**Author:** ![standingwave](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@standingwave](https://boards.straightdope.com/u/standingwave)\ **Post date:** [January 2, 2012, 12:23am UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/4 "2012-01-02T00:23:31Z")
In the case of the Shuttle, bolts. Big, giant space [bolts](http://wiki.answers.com/Q/How_does_the_space_shuttle_stand_up). ---
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [January 2, 2012, 12:26am UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/5 "2012-01-02T00:26:30Z")
> [@foolsguinea](#): > > Is that even an answer to this question? Yes, yes it is. Also, in many missiles (like the Minuteman), the solid motor fuel is designed and shaped to assist in bearing the load above it. Tripler - Rocket surgeon. ---
**Author:** ![Nanoda](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Nanoda](https://boards.straightdope.com/u/Nanoda)\ **Post date:** [January 2, 2012, 12:47am UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/6 "2012-01-02T00:47:07Z")
> [@Tripler](#): > > in many missiles (like the Minuteman), the solid motor fuel is designed and shaped to assist in bearing the load above it. Okay, but that rocket isn’t sitting on it’s nozzle, so if I read the OP right… what’s it sitting on? A jet aircraft clearly has 3 struts bearing it’s weight while on the ground, but what’s the corollary for pad-bound rockets? ---
**Author:** ![Cugel](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cugel/32/1199_2.png) [@Cugel](https://boards.straightdope.com/u/Cugel)\ **Post date:** [January 2, 2012, 12:49am UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/7 "2012-01-02T00:49:21Z")
> [@beeyule](#): > > I’ve looked at several pictures but can’t see how this is accomplished. From this picture, it looks like the boosters just sit on the platform [http://blog.al.com/space-news/2009/05/atlantis\_padr.jpg](http://blog.al.com/space-news/2009/05/atlantis_padr.jpg) and the shuttle is held by other structures, and is presumably usefully glued to the boosters as well. [http://scienceblogs.com/startswithabang/upload/2010/08/how\_to\_launch\_a\_space\_shuttle/gpw-20051129-NASA-GPN-2000-001877-looking-directly-down-at-STS-79-Space-Shuttle-Atlantis-Florida-19960820-medium.jpeg](http://scienceblogs.com/startswithabang/upload/2010/08/how_to_launch_a_space_shuttle/gpw-20051129-NASA-GPN-2000-001877-looking-directly-down-at-STS-79-Space-Shuttle-Atlantis-Florida-19960820-medium.jpeg) ---
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [January 2, 2012, 1:07am UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/8 "2012-01-02T01:07:02Z")
> [@Nanoda](#): > > Okay, but that rocket isn’t sitting on it’s nozzle, so if I read the OP right… what’s it sitting on? A jet aircraft clearly has 3 struts bearing it’s weight while on the ground, but what’s the corollary for pad-bound rockets? I misunderstood the OP then. I never did ask that question, but did see diagrams that there’s a mundane retention ring holding the whole thing up off the silo floor. But knowing cutbacks in the Air Force, they’ve probably replaced it with a couple of cinder blocks. Tripler They stole them from Biden’s IROC-Z when he wasn’t looking. ---
**Author:** ![Hail\_Ants](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)\ **Post date:** [January 2, 2012, 1:41pm UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/9 "2012-01-02T13:41:04Z")
> [@Magiver](#): > > I believe it’s done by pressurizing the container. The older museum exhibits had to be pressurized to stand up on display. This was (is) true for some, but not for the Shuttle nor the Saturns nor I think any manned booster. The Shuttles are stacked and transported in the same VAB and by the same ‘crawler’ that was built for & used by Apollo and they are most definitely **not** rolled out fueled (i.e. pressurized), but completely empty. They are only fueled at the pad. The weight is taken by the structure of the booster itself and its attachment points to the pad. It’s complicated & unique for each design and doesn’t really have a universal answer, other than as stated, ‘really big Space Bolts!’ P.S. [Here’s a really really cool super slow-mo video](http://laughingsquid.com/slow-motion-video-of-apollo-11-saturn-v-launch/) showing the very base of a Saturn V during launch with a narration that describes, among other things, its hold downs… ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [January 2, 2012, 3:23pm UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/10 "2012-01-02T15:23:22Z")
> [@Tripler](#): > > … > > Tripler > > - Rocket surgeon. 😃 ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [January 2, 2012, 6:11pm UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/11 "2012-01-02T18:11:32Z")
> [@Hail\_Ants](#): > > This was (is) true for some, but not for the Shuttle nor the Saturns nor I think any manned booster. The Shuttles are stacked and transported in the same VAB and by the same ‘crawler’ that was built for & used by Apollo and they are most definitely **not** rolled out fueled (i.e. pressurized), but completely empty. They are only fueled at the pad. > > The weight is taken by the structure of the booster itself and its attachment points to the pad. It’s complicated & unique for each design and doesn’t really have a universal answer, other than as stated, ‘really big Space Bolts!’ > > P.S. > > [Here’s a really really cool super slow-mo video](http://laughingsquid.com/slow-motion-video-of-apollo-11-saturn-v-launch/) showing the very base of a Saturn V during launch with a narration that describes, among other things, its hold downs… neat video clip. Of course that lead me to wander around the net and I was surprised that we’re using Russian engines on the Atlas 5. ---
**Author:** ![Hyperelastic](https://avatars.discourse-cdn.com/v4/letter/h/a3d4f5/32.png) [@Hyperelastic](https://boards.straightdope.com/u/Hyperelastic)\ **Post date:** [January 2, 2012, 7:33pm UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/12 "2012-01-02T19:33:40Z")
They’re held down by giant explosive bolts. The structure of the rocket has to support its own weight, of course, otherwise it’d collapse as it begins its upward acceleration (\>1g). The rocket’s ability to support (g multiples of) its own weight is sometimes dependent on the tank pressure (as in the old Atlases and the Centaur upper stage). Even in vehicles that can stand on their own with no pressure in the tanks, tank pressure does provide an important stabilizing effect. The vehicle couldn’t be subjected to as high an acceleration if not for the tank pressure. Solid rocket fuel only supports itself. It isn’t stiff enough to support anything above it. The motor case provides all the support. ---
**Author:** ![Dufus](https://avatars.discourse-cdn.com/v4/letter/d/c77e96/32.png) [@Dufus](https://boards.straightdope.com/u/Dufus)\ **Post date:** [January 2, 2012, 7:41pm UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/13 "2012-01-02T19:41:26Z")
This [static display](http://i161.photobucket.com/albums/t205/dennismenace56/saturn_v_sdh3.jpg) of a Saturn 5 shows the point which bears all the weight. [This picture](http://i161.photobucket.com/albums/t205/dennismenace56/saturn_v_sdh2.jpg) on the launch pad shows the hold downs. ---
**Author:** ![Dufus](https://avatars.discourse-cdn.com/v4/letter/d/c77e96/32.png) [@Dufus](https://boards.straightdope.com/u/Dufus)\ **Post date:** [January 2, 2012, 8:03pm UTC](https://boards.straightdope.com/t/what-is-bearing-the-weight-of-rocket-on-the-pad/608090/14 "2012-01-02T20:03:40Z")
[This website](http://www.justurbanism.com/2011/04/how_does_the_space_shuttle_stay_on_the_pad_bi/) shows the space shuttle hold downs.