# Cape Canaveral **URL:** \ **Category:** Factual Questions\ **Created:** [July 28, 2007, 8:07pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515 "2007-07-28T20:07:20Z")\ **Posts on this page:** 15\ **Page:** 1
**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 28, 2007, 8:07pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/1 "2007-07-28T20:07:20Z")
What is the greatest number of launch pads at Cape Canaveral, and when did they exist? I’m looking at an aerial image on DVD that appears to show at least a dozen c.1960. ---
**Author:** ![Full\_Metal\_Lotus](https://avatars.discourse-cdn.com/v4/letter/f/df705f/32.png) [@Full\_Metal\_Lotus](https://boards.straightdope.com/u/Full_Metal_Lotus)\ **Post date:** [July 28, 2007, 8:38pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/2 "2007-07-28T20:38:25Z")
No idea, but I bet you got the max in your first try… Minor hijack… anyone know who cape “Canaveral” is named after? FML ---
**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 28, 2007, 8:42pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/3 "2007-07-28T20:42:57Z")
[QUOTE=Full Metal Lotus] Minor hijack… anyone know who cape “Canaveral” is named after? [/QUOTE] From Spanish for ‘Cape of Cranes’. ---
**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 28, 2007, 8:47pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/4 "2007-07-28T20:47:26Z")
[QUOTE=Full Metal Lotus] No idea, but I bet you got the max in your first try… [/QUOTE] A dozen is only a guess. The image gets a little hazy in the background. They’re using Launch Complex 39 now. So I wondered how many launch pads existed at one time. ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [July 28, 2007, 9:36pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/5 "2007-07-28T21:36:34Z")
It doesn’t give the answer, but this page may be a starting point: [List of Cape Canaveral and Merritt Island launch sites - Wikipedia](http://en.wikipedia.org/wiki/List_of_Merritt_Island_launch_sites) Launch complex numbering goes up to 47, but not all numbers are represented. Some complexes have more than one launch pad. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [July 28, 2007, 10:53pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/6 "2007-07-28T22:53:17Z")
[QUOTE=Johnny L.A.] A dozen is only a guess. The image gets a little hazy in the background. They’re using Launch Complex 39 now. So I wondered how many launch pads existed at one time. [/QUOTE] There are some forty-odd existing launch complexes, though there have been only around a dozen in operation at any one time to support various NASA, Air Force, and Navy missions and programs. Some of the complexes have been renumbered over the years, so it’s hard to say exactly how many unique complexes there are without delving into the entire history. A launch complex is fundamentally a blockhouse and/or observation station, one or more pads with attendant stands, erectable towers or fixed/movable gantries, plume duct and fire/sound suppression plumbing, and other bits of erection or manuevering fixtures. When a pad is no longer in use (because the specific vehicle or vehicles it was designed to launch are no longer in service or are launched from another site) then the pad or complex is “mothballed”, which is typically a euphamism for “we pull out everything of value and let it rust.” (I once inspected a mothballed semisubmerged silo for a launcher that is no longer fielded operationally and found it half-full of water and what remained of the surveillence and control electronics were older than I was by at least a decade.) LC-39 is actually just two complexes, although referring to them as individual complexes is something of a misnomer as major support operations like vehicle integration are done at the common Vehicle Assembly Building, and operation is done from Launch Control. Stranger ---
**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 28, 2007, 11:39pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/7 "2007-07-28T23:39:56Z")
**Stranger** : Thanks for the answer. I have a couple more questions. I _should_ know this, but I’m embarrassed to say that I don’t: What are the sparking devices seen under the bells during the ingnition sequence? Also, the water: That’s for eliminating shockwaves from the supersonic gasses, right? ---
**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\ **Post date:** [July 29, 2007, 1:48am UTC](https://boards.straightdope.com/t/cape-canaveral/413515/8 "2007-07-29T01:48:36Z")
The water is part of the sound suppression system. It attenuates the sound levels so that they don’t damage the launch vehicle or the launch pad. The water absorbs sound energy. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [July 29, 2007, 4:36pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/9 "2007-07-29T16:36:13Z")
[QUOTE=Johnny L.A.] **Stranger** : Thanks for the answer. I have a couple more questions. I _should_ know this, but I’m embarrassed to say that I don’t: What are the sparking devices seen under the bells during the ingnition sequence? Also, the water: That’s for eliminating shockwaves from the supersonic gasses, right? [/QUOTE] **mks57** has already said, the water is used for sound supression; it absorbs heat from the initial impulse and becomes a big cloud of steam which attenuates the blast so that the reflected shock doesn’t damage anything important. I forget how many hundreds of thousands of gallons of water are used–3 or 4 or something like that–but bascially the water is dumped from giant tanks into a the flame trench or duct just seconds before launch. At the bottom of the trench, right below the booster, is also a deflector; most of the ones I’m used to look like (and are called) a “witch’s hat”, but I’d guess the one for the Shuttle is more like a big angled plate, designed to redirect exhaust gases to the side and through the flame trench. I don’t know about “sparking devices”; do you have an image or video showing them? My guess is that what you’re seeing is an artificat of the plume, either gases in phase transition or unburnt propellent suddenly combusting, but I’d have to get a better idea of what you’re talking about so see clearly. Plume phenomenology is a fascinating topic; you’d think that the gases just fly out and expand, but in fact once you get into the supersonic range you get all sorts of odd behavior which changes dramatically with altitude during flight. The Delta IV, for instance, has this really distinct diamond pattern (due to supersonic shock fronts expanding and then reforming) that follows it up, and the plumes on linear aerospike engines have all sorts of odd behavior as the propellent learns that it’s been tricked into thinking there’s a real nozzle there. Stranger ---
**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 29, 2007, 4:45pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/10 "2007-07-29T16:45:34Z")
[QUOTE=Stranger On A Train] I don’t know about “sparking devices”; do you have an image or video showing them? [/QUOTE] [http://www.youtube.com/watch?v=40kTsrwSSOY](http://www.youtube.com/watch?v=40kTsrwSSOY) at 4:00 into the video. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [July 29, 2007, 5:42pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/11 "2007-07-29T17:42:36Z")
[QUOTE=Johnny L.A.] [http://www.youtube.com/watch?v=40kTsrwSSOY](http://www.youtube.com/watch?v=40kTsrwSSOY) at 4:00 into the video. [/QUOTE] Oh, those are the spark igniters designed to combust unburnt fuel and oxidizer dumped in the ignition sequence so that it doesn’t collect and damage anything. Each Shuttle Main Engine has an autonomous igniter in the aft chamber of the preburner (actually two of them) but you actually need a lot of heat to get the turbopumps spinning fast enough to draw fuel and oxidizer down in volume and get the mixture to a temperature that is self-combusting (otherwise, the cold fluid in the tight confines of the pressure chamber will put itself out, like a match submerged in gasoline) so the Main Propulsion System dumps a mixture of fuel and oxidizer that is only partially burnt until the combustion in the chamber reaches steady state. It’s sort of like starting an old diesel engine, where it kicks a bunch of unburnt fuel out the back, only this fuel is highly combustable once it’s allowed to expand and could potentially do damage, particularly if it is compressed and ignited by a shockwave. Stranger ---
**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 29, 2007, 5:44pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/12 "2007-07-29T17:44:24Z")
Thanks! 🙂 ---
**Author:** ![Muffin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muffin/32/4341_2.png) [@Muffin](https://boards.straightdope.com/u/Muffin)\ **Post date:** [July 29, 2007, 6:49pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/13 "2007-07-29T18:49:41Z")
Where’s the applause smiley? Great answers, Stranger. ---
**Author:** ![BeenThereDoneThat](https://avatars.discourse-cdn.com/v4/letter/b/90db22/32.png) [@BeenThereDoneThat](https://boards.straightdope.com/u/BeenThereDoneThat)\ **Post date:** [July 29, 2007, 9:12pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/14 "2007-07-29T21:12:47Z")
[QUOTE=Johnny L.A.] From Spanish for ‘Cape of Cranes’. [/QUOTE] :smack: From wikipedia: > [@](#): > > The name “Canaveral” (Cañaveral in Spanish) was given to the area by Spanish explorers. It literally means “canebrake” (thicket of cane). The name can be interpreted as “Cape of Canes”. As far as the number of launch pads, you can simply count them all using aerial maps: > **[Bing Maps](https://www.bing.com/maps?v=2&cp=28.455556~-80.527778&style=a&lvl=15&sp=Point.28.455556_-80.527778_city___)** > > Map multiple locations, get transit/walking/driving directions, view live traffic conditions, plan trips, view satellite, aerial and 3d imagery. Do more with Bing Maps. https://maps.google.com/maps?ll=28.455556,-80.527778&spn=0.1,0.1&t=k&q=28.455556,-80.527778 My first response! Hope it’s not useless! 😃 ---
**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:** [August 6, 2007, 3:47pm UTC](https://boards.straightdope.com/t/cape-canaveral/413515/15 "2007-08-06T15:47:27Z")
I got some information from the Cape Canaveral historian (lightly edited by me): > [@](#): > > The launch complexes currently in operation at the Cape are 17A, 17B, 37B and 41. Complex 46 hasn’t had any launches in years, but it is still considered an active pad. > > I have also attached a summary of all the major launches on the Eastern Range. You will note that the largest number of launches in any year was 206 in 1960. During that year the following complexes and launch pads supported at least one launch apiece: 1, 2, 4, 5, 6, 11, 12, 13, 14, 15, 16, 17A, 17B, 18A, 18B, 19, 20, 21, 22, 25A, 25B, 26A, 26B, 29A, and 30A. The “A” and “B” designators are used to cite a particular pad. If there is no letter associated with the number, then the launch site specified is a complex with only one launch pad. The exception is Complex 37B – that complex only has one launch pad, Pad 37B. He also sent some .pdf files, but I haven’t had a chance to read them.