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SpaceX has only (to my knowledge) landed one Falcon Heavy booster. All others were expended. SpaceX also said during the early days of the company that each Falcon 9 booster could fly up to 1,000 times each. The booster that flew the most times had a flight record of 20 flights. This being said, SpaceX goal #1A, reach Mars, obviously. But goal #1B, make spaceflight affordable, namely by reusing rockets as many times as possible. Elon Musk has said some pretty horrible things about expendable launch systems, but he's not doing much better himself.

My question: If SpaceX wants affordable spaceflight, why keep expending boosters?

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    $\begingroup$ Because the booster has two flight profiles - expendable and non-expendable. The expendable profile allows for more mass put higher, and faster. Short answer - it allows for things that the energy trade-off for reuse doesn't. $\endgroup$ Jan 23 at 18:31
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    $\begingroup$ "SpaceX has only landed one Falcon Heavy booster" Wikipedia says something quite different: en.wikipedia.org/wiki/Falcon_Heavy#Launches_and_payloads . I don't follow SpaceX closely enough to know which is right, though I definitely remember seeing footage of two boosters landing at once. $\endgroup$
    – djr
    Jan 23 at 19:06
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    $\begingroup$ @djr they are probably confused and only referring to the core stage - SpaceX has successfully landed all the side boosters in a FH launch, but they have only successfully landed one core stage. The others were either lost due to an issue during landing, or deliberately expended due to mission profile. $\endgroup$
    – Moo
    Jan 24 at 0:01
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    $\begingroup$ This is a poorly written question. At this moment SpaceX has landed 166 boosters, and re-flown 144 of them. The only boosters that aren't regularly landed are Falcon Heavy core boosters, while the "wing" stages have all been recovered. SpaceX is committed to reuse, and it's #1 priority isn't Mars, it's lowering the cost of spaceflight, because if they can't greatly reduce the cost of getting large payloads into orbit, they'll never be able to afford to go to Mars. $\endgroup$ Jan 25 at 1:02
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    $\begingroup$ Landing 166 boosters is "not much better" than the rest of the world, which is at 0? $\endgroup$ Jan 25 at 9:35

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Falcon 9 Replaces Falcon Heavy for Many Missions

When Falcon 9 was first developed, it had a max payload to Low Erth Orbit (LEO) of 9t, and 4.8t to Geostationary Orbit (GEO). Falcon Heavy was built to handle the heavier payloads. However, over time Falcon 9 has been upgraded with densified propellant and more efficient engines, and can now put 16.5 tons in LEO in recovery mode and 23t in expendable mode. A Falcon 9 block 5 in expendable mode can put 8.3t in GEO, and in recovery mode 5.3t.

Without recovery of the center stage, Falcon Heavy can put 16t of mass into Geostationary orbit. With full recovery of all stages, that amount drops to 8t. So for geostationary flights, there is only a small window of payloads where a Falcon Heavy with recoverable core stage makes more sense than a Falcon 9.

So, Falcon Heavy tends to be used for heavy geostationary satellites that require the center core to be expended. Falcon 9 can do almost everything else. Another window might be for a fully reusable Falcon Heavy vs expending a Falcon 9, but those use cases may not be very common.

As for LEO, there is not much market for gigantic satellites in Low Earth Orbit, and Falcon 9 performs so well that Falcon Heavy would be rarely needed. And for heavier satellites, SpaceX is planning to use Starship, and once Starship is fully proven out they want to retire Falcon Heavy and Falcon 9. So further development on Falcon Heavy is probably not in the cards. It's an interim rocket.

References:

Wikipedia -Falcon Heavy

Wikipedia - Falcon 9

Ars Technica - Forget the Falcon Heavy's Payload and Think about Where the Rocket Will Go

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    $\begingroup$ I’d add that the center stage is going much faster at the end of its burn so it would need much more remaining fuel to slow down than the side boosters. That’s why a fully reusable Falcon Heavy doesn’t get you much additional performance over a single Falcon 9. $\endgroup$
    – Michael
    Jan 24 at 14:12
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    $\begingroup$ I'd also add that for gigantic satellites in Low Earth Orbit, they would not fit into the payload fairing most of the time $\endgroup$ Jan 24 at 17:41
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    $\begingroup$ Also, those 5-8t GEO satellites tend to be relatively expensive, and the probability of failure is likely higher for FH (more complex, fewer flights to date) than for F9. It is thus possible that launch insurance for the same sat/mission is noticeably more expensive on FH, again eating into any savings from reusing the first stages. $\endgroup$
    – TooTea
    Jan 24 at 17:55
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There are 3 cores in each Falcon Heavy. SpaceX has successfully landed the side cores on land. The problem has been landing the center core. One landed successfully but was lost at sea. The other center cores did not land successfully, though in the most recent launch (USSF-67) no attempt was made to land the center core.

Space is hard. Landing orbital class rockets after launch is even harder. Landing 2 out of 3 cores from each launch is really not that bad.

Remember also that the goal is not "as much as possible" but rather "as much as practical". The Space Shuttle taught us that reusability does not come for free. SpaceX learned from that and has been working to balance reuse for reuse's sake (i.e., don't keep producing things and throwing them away) vs. actual cost. At a minimum, a rocket needs thorough inspection before reuse. But I suspect reuse often requires repair or replacement of key components. I assume that after enough flights a rocket will start to need engine replacements (maybe this has already happened, I don't know), which are expensive. Eventually metal fatigue and other problems come into play to the extent that repairs are simply not practical.

Is 15 to 20 flights the same as 1,000? Not at all. But it is 14 to 19 more reuses than anyone else.

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    $\begingroup$ As Meatloaf put it in a song, "two out of three ain't bad." $\endgroup$ Jan 23 at 19:57
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    $\begingroup$ Also note that the performance required for landing a stage is additional performance that can go into the mission if necessary - if the orbit requires more energy than a reusable first stage and second stage together cant reasonably provide, but a non-reusable first stage and second stage can, then the core is expended as necessary. The cost for this mission is increased however. $\endgroup$
    – Moo
    Jan 24 at 0:03
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    $\begingroup$ @DavidHammen probably not the best example to bring up. Pretty sure Meat Loaf was being totally ironic with that song. RIP, can't believe it's already a year since he died. $\endgroup$ Jan 24 at 16:54
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    $\begingroup$ @MarkRansom All true. That being said, I did (of course!) think of that line when I wrote my answer. $\endgroup$ Jan 24 at 16:59
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My question: If SpaceX wants affordable spaceflight, why keep expending boosters?

Let me take a different angle on this. Right now, Falcon Heavy has won the rocket industry. That's not a typo, they've won the whole industry at this point. There's a nifty rocket comparator someone put together and it does an apples-to-apples comparison of LEO lift capacity. If we draw that list down to operational rocket programs (or those expected to run in the near future) we can see that Falcon Heavy really stands alone in the field

Note that costs are approximate (based on simple internet searches only)

Rocket Manufacturer Tonnage to LEO Cost Status
Soyuz 2 Roscosmos 8.2t 80M USD In Service
Falcon 9 SpaceX 16.9t 50M USD (used) In Service
Atlas V ULA 18.8t 153M USD Ending
Ariane 5 ESA 20t 150M USD (€139M) Ending
Proton M Roscosmos 23t 50M USD Ending
Ariane 6 ESA 23.8t 81M USD (€75M) In Development
Long March 5 China 25t 50M USD In Service
Delta IV Heavy ULA 28.8t 350M USD Ending
New Glenn Blue Origin 45t N/A In Development
Falcon Heavy SpaceX 54.4t 97M USD In Service
SLS NASA 87.2t 2,000M USD In Service
Starship SpaceX 100t N/A In Development

As you can see, Falcon Heavy is really the only current viable alternative for any sort of large lift rocket, even if the center core is expended every time.

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  • $\begingroup$ And if there is no competition, why lower prices, rather make as much money as the market will bare to fund other projects. $\endgroup$
    – geoffc
    Jan 24 at 15:46
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    $\begingroup$ For that Falcon 9 "used" quote: is that in "like new", "very good", "good", or "acceptable" condition? $\endgroup$
    – davidbak
    Jan 24 at 21:46
  • $\begingroup$ @davidbak There's no details, sadly. SpaceX has merely said "around $50M" $\endgroup$
    – Machavity
    Jan 25 at 19:01
  • $\begingroup$ Apparently, SpaceX has just updated the numbers for Starship on the webpage to "up to" 150t reusable, "up to" 250t expendable. I didn't check it myself, only saw someone mention it. $\endgroup$ Jan 29 at 14:45
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The answer is quite easy. The side boosters were recovered in all of the Falcon Heavy launches. The last two launches were to geostationary orbit. This orbit is very energy demanding so to get there the center core of Falcon Heavy uses too much fuel to be able to make a landing at sea. There is just not enough performance to do both.

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    $\begingroup$ Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center. $\endgroup$
    – Community Bot
    Jan 24 at 13:34
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    $\begingroup$ Geostationary orbit doesn't necessarily need an expended booster to be reached - there have been many Falcon 9 launches of geostationary payloads, for example. The difference is the mission profile - can the launch include a geostationary transfer orbit, or does it need to be direct to geostationary orbit... Thats why the cores were expended on the last two FH flights - the mission profile required a direct GEO insertion, and not an intermediate GTO. $\endgroup$
    – Moo
    Jan 26 at 4:25

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