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.
No idea, but I bet you got the max in your first try… Minor hijack… anyone know who cape “Canaveral” is named after?
From Spanish for ‘Cape of Cranes’.
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.
It doesn’t give the answer, but this page may be a starting point: 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.
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: 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?
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.
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.
http://www.youtube.com/watch?v=40kTsrwSSOY at 4:00 into the video.
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.
Where’s the applause smiley? Great answers, Stranger.
As far as the number of launch pads, you can simply count them all using aerial maps:
My first response! Hope it’s not useless!
I got some information from the Cape Canaveral historian (lightly edited by me):
He also sent some .pdf files, but I haven’t had a chance to read them.