To round out the discussion a bit:
While Cuba, in the context of an alt-timeline where the USA kept it, has been mentioned, Delta Force's timeline he started this thread to discuss has a strong Soviet Union. It isn't clear to me whether it lasts longer than OTL but it is clear it has a more aggressive space program while it lasts, however long or short that may be.
Clearly if Cuba is on the table for the USA in a more distant timeline, it might be for the Soviets as well. (However I'd have reread Delta Force's political timeline to see if he's butterflied away the Castro regime, or had it forcibly removed...
)
Even in a timeline with the USA hanging on to Cuba as a colonial territory or integral US state, with that being the case in the 1950s, it isn't entirely clear the American authorities would choose it over Cape Canaveral, because while it is nicely farther south that Canaveral, there are a lot of islands cluttering up many of the trajectories one might want to use, starting with nearby Hispaniola.
But it strikes me that the Russians are in more desperate need of a low-latitude launch site than the Americans are; once you get near the tropics the advantage of going closer to the equator is pretty marginal, whereas a site on a tropic might arguably be actually better for Lunar and Solar system missions. Canaveral is well north of even the tropic but not extremely so. The Russians on the other hand, even when they retain control of Central Asia, are pretty far north and would desire a tropical launch site all the more. Perhaps even enough to take some political risks with staring down the USA and then launching a bit close to not-friendly Caribbean island territories.
I've considered Puerto Rico too, but it is quite far from US industrial centers, and the Virgin Islands are right there due east, so that's unfortunate. As for the VI themselves, their eastern range is not cluttered but they are tiny little islands, I don't think big enough to support any sort of major launch complexes without displacing a lot of people.
I've tended to dismiss Australia for the Europeans as being too freaking far away--the actual antipodes, after all! But Woomera is a good site after all, and some commentors here don't think the sheer distance is much of an obstacle, claiming the big problem is loading the components for shipment any distance and not the distance itself. If that is true, I don't think it is very necessary to go farther north to Cape York, which puts the early launch trajectories again over islands; better, given the decision to launch from inland, to use Australia's very sparsely inhabited land and have the advantage of overland abort ranges. Also a desert climate tends on the whole to be more stable and predictable from an operational point of view, and hosting the site in a highly developed nation like Australia (one with political ties to one of the chief developing nations at that) seems like a good idea. So if distance is really no object I vote for Woomera!
Also--Australia is much closer to other nations that have an interest in launch sites, like Japan, and money and technology to get into the game. Later, in the 80s and beyond, other Asian powers could also benefit from an Australian site. Though some of them like Indonesia might prefer to develop their own--again it is tricky to find the ideal island that is big enough and close enough to industrial centers, and yet doesn't have a whole slew of small islands due east...
If the Japanese want a more southerly site reasonably close to them, they might try their luck with the Philippines; central eastern Mindanao looks like a good spot to me.
Finally we haven't seen much mention of East Africa here. OTL Somalia is a political mess of course and the political faction most likely to stabilize it strikes me as the Islamicist bloc, insofar as that is a bloc--OTL I'd be looking to the Saudis or a consortium of Persian Gulf emirates trying it. And not wanting to bet too much on their being able to manage the necessary political stabilization, despite their petrodollars and religious orthodoxy.
But in an ATL, who knows? Perhaps Somalia can have been stabilized by a pro-Western regime, even perhaps an ally of the Shah's, or has a good relationship with Britain if the British can manage either to retain a strong colonial empire (fat chance say I, but they aren't my timelines are they?) or more likely I'd hope, manage decolonialization in a way that keeps good relations. The same goes for Kenya, and in the context of a European space port in East Africa I'd be looking at Kenya more optimistically.
East Africa once drew my eyes because I figured the ideal launching site is from a tropical eastern coast that has highlands, the higher the better, right on the coast. Unfortunately no such place exists and the sort of site I was imagining is either geologically impossible or anyway, very improbable and probably unstable if it existed at all. Would you want to launch a Saturn V from a mile-high cliff edge?
Realistically to get the altitude you need some slope, and that means a broad band of descending land, dozens of miles at least, between the high plateau and the shoreline, and you can bet people will be living there--perhaps not in great numbers, but I don't see a politically desirable place to put a base in that would have the arrogance to just move those people away, or indifferently chuck loud and dangerous rockets over their heads. I'm actually a bit queasy about the Australian outback--it's pretty empty, but not totally, and it would be unfortunate to have a failed launch rain down hundreds of burning exploding tonnes of defective rocket on some Aboriginal family camp. Or a prospector, or sheep station...
So if there are to be East African launch sites, as with Kourou or Canaveral, I expect they'd be right on the coast, with no advantage for high-altitude launch. That's too bad but it's the standard case for all but the dubious inland sites (which include of course not just Woomera but the standard OTL sites chosen by the Soviets and the Chinese both--obviously though those are regimes that will simply cover up the unlikely case of a rocket crash coming down on people, who are after all pretty scarce in the eastern downranges.) No one seems to consider the advantage of launching from a substantially lower air density site worth the obvious hassles and costs of hauling all the launch site facilities and rockets up to such hard to access locations, even if they are inured to the idea of launching over inhabited land. So altitude is not much of a factor to consider.
So that's my belated contribution:
A vote for the Americans sticking with Canaveral as good enough and better in some ways than many alternatives;
A vote for Russians in desperate search of tropical sites to capitalize on their relationship with Castro and developing a site in Cuba (good only for as long as the Soviet Union lasts obviously);
A vote for Woomera in Australia if distance is not a factor (and for Kourou if it is--don't know about wasps and other tropical pests that would plague many equatorial sites, but the Spaceport OTL boasts that actually the French Guianan coast suffers rather less than most tropical sites from tropical storms, for what that is worth)
A vote for eastern Mindanao;
And a vote for an East African site, probably on the Kenyan coast or conceivably Somalian, politics permitting.
