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OK I get that booster reuse cuts down costs, but the fact is the 2nd stage is still not reused, which limits the economic benefits needed to open new markets.

OK I get that booster reuse cuts down costs, but the fact is the 2nd stage is still not reused, which limits the economic benefits needed to open new markets. We get a 50% reduction in costs, instead of the 95% reduction in costs. You can get a 50% reduction in costs just by going to India for launch.. Is SpaceX going for 2nd stage reuse at all? That's going to be a lot harder than booster stage reuse, since you're returning to land at orbital velocity. And then there's the whole issue of increasing reliability of the 1st stage for reuse hundreds (or thousands) of times needed for new business models...

bosdev 8y ago
The first stage is significantly larger and therefore more expensive than the second. My guess is the first full-reuse rocket you'll see will be the SSTO BFR.
- lorenzhs 8y ago
  > SSTO BFR [citation needed] - I don't think BFR is intended to be single-stage to orbit?
  - mikeash 8y ago
    The BFS (spaceship, i.e. second stage) is supposedly going to have enough performance to make orbit on its own as an SSTO, with a tiny payload. It probably won’t ever be used that way, though.
    - fooker 8y ago
      Human beings going for a 7 day trip around the moon is a tiny payload and some people would pay ..say.. ~ 300 million for a ticket, I would guess.
      - mikeash 8y ago
        You need supplies to keep those humans alive for a week, and a huge amount of fuel to boost the ship into a moon-intersecting orbit. Not a tiny payload by any means.
        fooker 8y ago
        What if it is refueled in orbit? The BFS presentations hinted at that ability.
        stetrain 8y ago
        To get other BFSes up there with enough fuel to transfer a useful amount would require them to use the first stage booster instead of just being SSTO. Really there's no point to doing an SSTO launch in practice since the BFR first stage will in theory be just as reusable (if not more so) than the BFS second stage. Using the first stage booster greatly improves payload to orbit and has relatively low marginal cost once you've built and tested the whole system.
        fooker 8y ago
        For a single launch, sure. What happens if there are regular launches? Logistically, to me it seems that it would be a great idea to have a refueling station in orbit which is supplied by BFR cargo ships ..say.. once a month. Launching a BFR for each launch of BFS would require a lot of transportation and duplicated effort. Is this intuition wrong?
        stetrain 8y ago
        The plan is that the BFR lands back at the launch pad in the same cradle it launched from which would reduce operational complexity. The fuel for your station has to get there somehow, and so does the station itself. The BFS-tanker ships would need to be launched with a BFR booster to bring up a meaningful amount of fuel, and there are going to be way more of those than there will be BFS-crew launches (ignoring the Earth-to-Earth transportation segment, where a centralized fuel station wouldn't make sense since each route will take a very different orbital path). SSTO-ing the BFS-crew would require another BFR booster-plus-cargo launch anyway to replace the fuel and cargo you could have carried up in the BFS if you had launched it on the BFR booster to begin with. The only angle that makes sense to me for doing a BFS-crew SSTO with minimal payload would be if it is deemed to be less risky for loss-of-crew. In that case you could have a BFS-tanker already on orbit and fully loaded by multiple BFR-plus-tanker launches, ready to rendevous with the BFS-crew ship after it reaches orbit on fumes. I think that is unlikely though since such a launch might leave the BFS-crew without the fuel margin required to divert or de-orbit and land propulsively without refuelling.
martythemaniak 8y ago
The answer is, this is Falcon 9's final form. You can get it in single or triple core variants. All new work is now on BFR, which will have 2nd stage reusability, orbital refueling, better economics etc. I think you're also underestimating how far this Falcon will get them - their timelines suggest that this is what they'll use to launch their global internet satellite network, not BFR.
fooker 8y ago
India can not launch payloads in the same weight class as Falcon 9.
yourMadness 8y ago
The 2nd stage has 1/3 the length, 1/5 the weight and 1/9 the number of engines of the 1st stage, why do you think it is 1/2 of the costs?
bjnord 8y ago
"Is SpaceX going for 2nd stage reuse at all? That's going to be a lot harder" Yes, they are (and yes, it will be): "SpaceX also continues to study the feasibility of returning and reusing the second stage of the Falcon 9, and Musk said he’s confident it can be done. The question is what “mass penalty” will have to be paid, primarily in terms of the fuel needed to slow the second stage down so that it can make a controlled descent back through Earth's atmosphere. "Still, Musk believes the Falcon 9 will get to full reusability. In terms of the rocket’s overall cost, the first stage accounts for 60 percent, the upper stage 20 percent, the fairing 10 percent, and the remainder are costs associated with the launch itself (fuel costs are between $300,000 and $500,000), Musk said." https://arstechnica.com/science/2018/05/spacexs-block-5-rocket-passes-its-first-test-but-final-exams-remain/ https://arstechnica.com/science/2018/05/spacexs-block-5-rock...
InTheArena 8y ago
The first stage represents about 75% of the cost of the vehicle, not 50%. This represents the actual cost of the metal on the launchpad, but not the services around the rocket, including launch control costs, etc. You can't take a rocket to India and you can't manufacturer that rocket in India (Skilset, US based corporation, ITAR) so you can't achieve your savings that way. Even Russia - which is using a very old tried and true rocket design - can't match prices at this point. In addition, the budget cuts in Russia have resulted in a massive reduction in reliability, which has blown up their insurance cost recently. In terms of second stage re-usability, they are looking at that for FalconX, and it's designed in at the start for BFR. Landing something from a second stage is as difficult comparatively vis-a-vis landing the first stage, as landing the first stage was compared to the suborbital hops that Blue Origin is doing. The latest SpaceX idea (judging by Elon's tweets) appear to be some sort of Ballute based approach. The first stage re-use should be good for 10 flights without a overhaul, with a complete tear-down on flight 10.
- golem14 8y ago
  "You can't take a rocket to India and you can't manufacturer that rocket in India (Skilset, US based corporation, ITAR) so you can't achieve your savings that way." Out of curiosity -- can they _fly_ a rocket to India (maybe have a booster return to India instead of a drone ship ? Too far/out of the way ? That may not help much since stage 2 would still have to be shipped around, which is probably not cost effective, and there might be other regulations that make it infeasible to launch anywhere but in the USA.
  - InTheArena 8y ago
    One of the use cases for BFR is a sub-orbital hop. That would probably work for India (depending on orbital dynamics). With Falcon, no way. The boosters land out at sea, but nowhere near that far out ;-)
  - evgen 8y ago
    As soon as it lands you have violated ITAR, so no.
- 8y ago
deleted 8y ago
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kerbalspacepro 8y ago
If you can get a 50% reduction in costs by going to India, people would be doing it.
stetrain 8y ago
Basically the answer to all of those is SpaceX's next gen BFR rocket. It is scaled up significantly which makes second stage reuse practical. The challenge with a rocket the size of the Falcon 9 is that added significant fixed mass to the second stage (heat shielding, parachutes, etc.) will significantly Affect payload mass / performance. By going to a much larger class of rocket, those concessions for re-use become a smaller fraction of the total stage 2 mass.
- deleted 8y ago
  [deleted]

bosdev 8y ago

The first stage is significantly larger and therefore more expensive than the second. My guess is the first full-reuse rocket you'll see will be the SSTO BFR.

lorenzhs 8y ago
> SSTO BFR [citation needed] - I don't think BFR is intended to be single-stage to orbit?
- mikeash 8y ago
  The BFS (spaceship, i.e. second stage) is supposedly going to have enough performance to make orbit on its own as an SSTO, with a tiny payload. It probably won’t ever be used that way, though.
  - fooker 8y ago
    Human beings going for a 7 day trip around the moon is a tiny payload and some people would pay ..say.. ~ 300 million for a ticket, I would guess.
    - mikeash 8y ago
      You need supplies to keep those humans alive for a week, and a huge amount of fuel to boost the ship into a moon-intersecting orbit. Not a tiny payload by any means.
      - fooker 8y ago
        What if it is refueled in orbit? The BFS presentations hinted at that ability.
        stetrain 8y ago
        To get other BFSes up there with enough fuel to transfer a useful amount would require them to use the first stage booster instead of just being SSTO. Really there's no point to doing an SSTO launch in practice since the BFR first stage will in theory be just as reusable (if not more so) than the BFS second stage. Using the first stage booster greatly improves payload to orbit and has relatively low marginal cost once you've built and tested the whole system.
        fooker 8y ago
        For a single launch, sure. What happens if there are regular launches? Logistically, to me it seems that it would be a great idea to have a refueling station in orbit which is supplied by BFR cargo ships ..say.. once a month. Launching a BFR for each launch of BFS would require a lot of transportation and duplicated effort. Is this intuition wrong?
        stetrain 8y ago
        The plan is that the BFR lands back at the launch pad in the same cradle it launched from which would reduce operational complexity. The fuel for your station has to get there somehow, and so does the station itself. The BFS-tanker ships would need to be launched with a BFR booster to bring up a meaningful amount of fuel, and there are going to be way more of those than there will be BFS-crew launches (ignoring the Earth-to-Earth transportation segment, where a centralized fuel station wouldn't make sense since each route will take a very different orbital path). SSTO-ing the BFS-crew would require another BFR booster-plus-cargo launch anyway to replace the fuel and cargo you could have carried up in the BFS if you had launched it on the BFR booster to begin with. The only angle that makes sense to me for doing a BFS-crew SSTO with minimal payload would be if it is deemed to be less risky for loss-of-crew. In that case you could have a BFS-tanker already on orbit and fully loaded by multiple BFR-plus-tanker launches, ready to rendevous with the BFS-crew ship after it reaches orbit on fumes. I think that is unlikely though since such a launch might leave the BFS-crew without the fuel margin required to divert or de-orbit and land propulsively without refuelling.

martythemaniak 8y ago

The answer is, this is Falcon 9's final form. You can get it in single or triple core variants. All new work is now on BFR, which will have 2nd stage reusability, orbital refueling, better economics etc. I think you're also underestimating how far this Falcon will get them - their timelines suggest that this is what they'll use to launch their global internet satellite network, not BFR.

fooker 8y ago

India can not launch payloads in the same weight class as Falcon 9.

yourMadness 8y ago

The 2nd stage has 1/3 the length, 1/5 the weight and 1/9 the number of engines of the 1st stage, why do you think it is 1/2 of the costs?

bjnord 8y ago

"Is SpaceX going for 2nd stage reuse at all? That's going to be a lot harder" Yes, they are (and yes, it will be): "SpaceX also continues to study the feasibility of returning and reusing the second stage of the Falcon 9, and Musk said he’s confident it can be done. The question is what “mass penalty” will have to be paid, primarily in terms of the fuel needed to slow the second stage down so that it can make a controlled descent back through Earth's atmosphere. "Still, Musk believes the Falcon 9 will get to full reusability. In terms of the rocket’s overall cost, the first stage accounts for 60 percent, the upper stage 20 percent, the fairing 10 percent, and the remainder are costs associated with the launch itself (fuel costs are between $300,000 and $500,000), Musk said." https://arstechnica.com/science/2018/05/spacexs-block-5-rocket-passes-its-first-test-but-final-exams-remain/ https://arstechnica.com/science/2018/05/spacexs-block-5-rock...

InTheArena 8y ago

The first stage represents about 75% of the cost of the vehicle, not 50%. This represents the actual cost of the metal on the launchpad, but not the services around the rocket, including launch control costs, etc. You can't take a rocket to India and you can't manufacturer that rocket in India (Skilset, US based corporation, ITAR) so you can't achieve your savings that way. Even Russia - which is using a very old tried and true rocket design - can't match prices at this point. In addition, the budget cuts in Russia have resulted in a massive reduction in reliability, which has blown up their insurance cost recently. In terms of second stage re-usability, they are looking at that for FalconX, and it's designed in at the start for BFR. Landing something from a second stage is as difficult comparatively vis-a-vis landing the first stage, as landing the first stage was compared to the suborbital hops that Blue Origin is doing. The latest SpaceX idea (judging by Elon's tweets) appear to be some sort of Ballute based approach. The first stage re-use should be good for 10 flights without a overhaul, with a complete tear-down on flight 10.

golem14 8y ago
"You can't take a rocket to India and you can't manufacturer that rocket in India (Skilset, US based corporation, ITAR) so you can't achieve your savings that way." Out of curiosity -- can they _fly_ a rocket to India (maybe have a booster return to India instead of a drone ship ? Too far/out of the way ? That may not help much since stage 2 would still have to be shipped around, which is probably not cost effective, and there might be other regulations that make it infeasible to launch anywhere but in the USA.
- InTheArena 8y ago
  One of the use cases for BFR is a sub-orbital hop. That would probably work for India (depending on orbital dynamics). With Falcon, no way. The boosters land out at sea, but nowhere near that far out ;-)
- evgen 8y ago
  As soon as it lands you have violated ITAR, so no.
8y ago

deleted 8y ago

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kerbalspacepro 8y ago

If you can get a 50% reduction in costs by going to India, people would be doing it.

stetrain 8y ago

Basically the answer to all of those is SpaceX's next gen BFR rocket. It is scaled up significantly which makes second stage reuse practical. The challenge with a rocket the size of the Falcon 9 is that added significant fixed mass to the second stage (heat shielding, parachutes, etc.) will significantly Affect payload mass / performance. By going to a much larger class of rocket, those concessions for re-use become a smaller fraction of the total stage 2 mass.

deleted 8y ago
[deleted]