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Apart from the obvious answer that it'd take too long to get the booster back across the Atlantic, why doesn't SpaceX leave the main or centre booster in space a little bit longer and guide it to land on dry land rather than on a small pitching barge in the middle of the ocean?

It wouldn't help in cases where there's damage to the booster, but I would have thought that it was an easier target.

Would the booster be traveling too fast to slow down safely?

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    $\begingroup$ "but I would have thought that it was an easier target." Sure, because Africa Is Big, and Boats Are Tiny, but... you don't just land in Africa; you land on one specific landing pad. $\endgroup$
    – RonJohn
    Jun 28, 2019 at 16:11
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    $\begingroup$ @RonJohn - but with a pad on land you can make it bigger than a barge and therefore have a larger margin of error - at least for the position. $\endgroup$
    – ChrisF
    Jun 28, 2019 at 16:18
  • $\begingroup$ Chasing an unnecessary goal though - there's no signs that the size of the pad are limiting factors on landing, and existing land pads are't significantly larger nor do the rockets land further from center on land. No indication a larger pad would help. $\endgroup$
    – Saiboogu
    Jun 29, 2019 at 16:13
  • $\begingroup$ Where in Africa? $\endgroup$
    – cangrejo
    Jun 30, 2019 at 11:39
  • $\begingroup$ @Quora I am perfectly aware that there are unstable counties on Africa (as there are all over the world) but not all countries on Africa are like that. Also Somalia and Sudan are in East Africa and rule themselves out on geography not politics. $\endgroup$
    – ChrisF
    Jul 1, 2019 at 6:03

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The boosters do not have the range to get to Africa because they aren't going fast enough. If you look at the graphic below it shows a Falcon Heavy mission. The side boosters do not get very far downrange at all so they return to the cape. The drone ship for the core booster was located 1236km downrange, Africa is over 6000km downrange.

enter image description here

The graphic came from this site, which has many other profiles.

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    $\begingroup$ This is only half the reason. The other half is probably that Elon Musk just really wanted to land a rocket on a boat. $\endgroup$
    – MooseBoys
    Jun 28, 2019 at 7:40
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    $\begingroup$ If he ever names a barge "Grey Area" I'll be seriously worried. $\endgroup$
    – GdD
    Jun 28, 2019 at 7:54
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    $\begingroup$ @GdD whoosh (on my part) - please explain. Thanks. $\endgroup$
    – KlaymenDK
    Jun 28, 2019 at 12:00
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    $\begingroup$ @KlaymenDK, SpaceX barges are named after self-aware, hyper-intelligent ships from Iain M Banks culture sci-fi novels. "Of Course I Still Love You" and "Just Read The Instructions" are 2 of them. "Grey Area" is one that has no qualms about invading human minds and collects implements of torture: en.wikipedia.org/wiki/GCU_Grey_Area . $\endgroup$
    – GdD
    Jun 28, 2019 at 12:23
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    $\begingroup$ @GcD: Fortunately he's still got plenty of other names to choose from. Although some of them (like "Death And Gravity", "Funny, It Worked Last Time..." or "Only Slightly Bent") might have unwelcome associations in context. (I did use some of them for a KSP mission I flew a while ago, though.) $\endgroup$
    – Ilmari Karonen
    Jun 29, 2019 at 11:56
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In addition to the other answers, a fixed site in Africa would limit the available launch inclinations to a narrow band. A ship can be positioned anywhere in the ocean.

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    $\begingroup$ This is probably not so relevant. A small course correction after 2nd stage separation would shift the landing point north by hundreds of kilometers. $\endgroup$
    – MSalters
    Jun 28, 2019 at 11:08
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    $\begingroup$ This point is very relevant because it goes right along with the lack of fuel to even get to Africa - it would take yet more fuel to shift your ballistic touchdown point. This is another aspect to the 'lack of fuel, lack of flexibility to deal with fuel constraints.' $\endgroup$
    – Saiboogu
    Jun 28, 2019 at 15:04
  • $\begingroup$ They already use a bunch of fuel to slow down, a course correction would be very small compared to that. I wouldn't even be surprised if the cold gas thrusters could do it, though I certainly wouldn't bet on it. $\endgroup$
    – Turksarama
    Jun 30, 2019 at 5:48
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    $\begingroup$ no. You need to impart several hundred m/s to 30 tons of weight. For an ISS orbit, you need to change course by at least 50º, for example. $\endgroup$
    – Hobbes
    Jun 30, 2019 at 10:46
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Aside from the technical aspects, Africa is comprised of a couple of dozen different countries, all with their own rules and politics, but none of which would appreciate a botched booster landing in their urban centers. Even one incident like this would be enough to make sure no more flights happen.

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    $\begingroup$ You'd still need to convince people your landing technology is safe and accurate, which is hard to do with any new technology. If the booster crashes into the sea 50 km off the intended landing site, nothing much happens. If the crashes into a city 50 km from the island you rented, .... $\endgroup$
    – Guntram Blohm
    Jun 28, 2019 at 8:11
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    $\begingroup$ You would also need to get ITAR exemptions from the US gov't in order to 'export' the rocket. I suspect it would be an uphill battle. $\endgroup$
    – Saiboogu
    Jun 28, 2019 at 15:03
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    $\begingroup$ @ChrisF: Not only is Africa composed of many different countries, few of those countries are politically stable. So you build your landing facilities under one regime, launch your rocket, and then discover there's been a coup d'etat and the new rulers are holding it hostage... $\endgroup$
    – jamesqf
    Jun 28, 2019 at 17:27
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    $\begingroup$ @ChrisF, to put some hard numbers on jamesqf's point about political instability, only one of the 17 African countries that a low-inclination launch passes near has gone 30 years without a coup or civil war. $\endgroup$
    – Mark
    Jun 28, 2019 at 22:18
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    $\begingroup$ Eh, yes is it, in common speech. I certainly did not mean literally 2, as indicated by ‘dozen’ which is hardly a formal word too. $\endgroup$
    – Sebastiaan van den Broek
    Jun 30, 2019 at 11:42
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We saw with the Falcon Heavy third flight (STP-2 mission) that the center core landing was attempted at 1240KM from launch, which is the farthest recovery attempt to date.

A consequence of the farther distance is that the speed of the core at separation is higher, which requires more fuel to slow down for the re-entry burn.

It appears they did not allocate sufficient fuel in the re-entry burn to slow down enough to survive.

This provides an excellent data point for SpaceX.

Thus to land in Africa means it would likely be moving much faster, and thus require more fuel to slow down to survive contact with the atmosphere.

The trade offs may not work out, compared to a landing closer to the launch site.

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    $\begingroup$ The center core failed to land because of a mechanical fault with the center engine's vectoring system. It had enough fuel. $\endgroup$
    – Adam
    Jun 28, 2019 at 4:17
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    $\begingroup$ From what Elon Musk said, that mechanical fault sounds like it was caused by excess heat - I guess that is the hazard of trying it faster than ever before. $\endgroup$
    – Rory Alsop ♦
    Jun 28, 2019 at 4:58
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    $\begingroup$ @Adam apparently the TVC system firewall was breached due to excessive re-entry heating. $\endgroup$
    – 0xDBFB7
    Jun 28, 2019 at 4:59
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    $\begingroup$ My interpretation of what he said was that they tried to push the limits on how how much re-entry heating it would be exposed to in order to conserve more fuel for the final landing burn. They could have slowed down the rocket earlier and higher in the atmosphere, but they chose not to because fuel was tight. $\endgroup$
    – Tom Lubenow
    Jun 28, 2019 at 20:09
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As Elon Musk explains Spacex is considered "Advanced Weapons Technology" by the America Gov, so limits employees to American citizens, I suspect this also limits where they are allow to land them.

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  • $\begingroup$ The specific group of regulations you're thinking of is ITAR. This is a valid concern -- ITAR is quite broad in what it considers an "export" of defense-related technology. $\endgroup$
    – user23754
    Jun 30, 2019 at 18:24

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