Quote from: Lemurion on 05/11/2016 04:00 pmIf I had to bet on it, I'd say that SpaceX flying at least one reused booster is a near certaintyAn opinion based on little to no data.Quote from: Lemurion on 05/11/2016 04:00 pm After all, Grasshopper, the F9R, and New Shepard have proven the principle of rocket reusability. Liquid fueled rockets can be refueled and reflown.None of those went through entry heating. Also, you forgot DC-X and the shuttle.
If I had to bet on it, I'd say that SpaceX flying at least one reused booster is a near certainty
After all, Grasshopper, the F9R, and New Shepard have proven the principle of rocket reusability. Liquid fueled rockets can be refueled and reflown.
Quote from: Lar on 05/11/2016 04:11 pmJim, as of right now, based on what you know, what do you personally think the probability is that SpaceX will fly at least one reused booster at some point? And what do you think the conditional probability of success is, given that they fly one? An educated guess based on little to no data (but arguably more than most of us have) from you would be interesting.From what I saw, the aft end needs much more protection. There were panels that were damaged and opened on the previous booster. The fires on the current booster may have been internal.
Jim, as of right now, based on what you know, what do you personally think the probability is that SpaceX will fly at least one reused booster at some point? And what do you think the conditional probability of success is, given that they fly one? An educated guess based on little to no data (but arguably more than most of us have) from you would be interesting.
Propulsive landing is proof of principle for stage reuse.
The stage structure itself was also able to survive the landing loads.
Ignoring the amount of refurbishment required for the moment as that's as much an economic question as a technical one;
Now, getting Falcon 9 to their mythical 100x reuse level? I'm skeptical as heck about that. But reusing it enough to allow them to offer non-trivial price reductions? That seems pretty likely to me.
Quote from: Lemurion on 05/11/2016 05:38 pmPropulsive landing is proof of principle for stage reuse.Not true at all. See any planetary lander.Quote from: Lemurion on 05/11/2016 05:38 pm The stage structure itself was also able to survive the landing loads. Survive and reuse are two different things. And also, reuse and cost savings are two different things.Quote from: Lemurion on 05/11/2016 05:38 pmIgnoring the amount of refurbishment required for the moment as that's as much an economic question as a technical one;That's the point. It is a economic question. They could have done it already with no real payload and made the entry of the stage even more benign. And done the reflights with that.I think there will be no "gas and go" and refurb will always be needed and will be no where close to the savings predicted.
Quote from: Lar on 05/11/2016 02:30 pmDr. Sowers presented the case, and made assumptions about SpaceX in his model, which he stated as such. He identified them by name.Very true, good point. The concern with SpaceX is competitive, that is, how likely will it be that they actually reduce the cost of flight by a significant factor, which would put additional competitive pressure on ULA? In a way even that is moot, since SpaceX already outcompetes ULA on price, despite possibly wasting money on resue efforts that may not pan out. Imagine if they didn't spend any effort on reuse, how cheap would they be then? If the answer is not that much cheaper, it shows how feasible their reuse efforts are since they were able to "bake them in" to a market leading competitive structure.Dr. Sowers' assumptions with regard to SpaceX do not seem to acknowledge that and were not based on hard evidence, since that is proprietary. So in effect, even though he attempted to make the case against reuse on SpeceX behalf, it is not very a strong case, and looks like an attempt to sooth ULA's (and their owners/shareholders) concerns.
Dr. Sowers presented the case, and made assumptions about SpaceX in his model, which he stated as such. He identified them by name.
Quote from: Jim on 05/11/2016 04:17 pmQuote from: Lar on 05/11/2016 04:11 pmJim, as of right now, based on what you know, what do you personally think the probability is that SpaceX will fly at least one reused booster at some point? And what do you think the conditional probability of success is, given that they fly one? An educated guess based on little to no data (but arguably more than most of us have) from you would be interesting.From what I saw, the aft end needs much more protection. There were panels that were damaged and opened on the previous booster. The fires on the current booster may have been internal. While I agree with you that they haven't *yet* recovered a booster in a condition to refly it, as they get more data do you really think they can't make modifications to eliminate those issues and get a booster back in good enough condition to fly? I'm not seeing any showstoppers to eventually having something they can reuse at least a small number of times. It will probably take them longer than the amazing peoples expect, and the performance hit necessary for all the features they'll need for reuse may be more than currently expected, but I'd be really surprised if they couldn't figure it out eventually (with eventually being in the 1-2yrs range).
Quote from: Lemurion on 05/11/2016 05:38 pmPropulsive landing is proof of principle for stage reuse.Not true at all. See any planetary lander.
Quote from: Lemurion on 05/11/2016 05:38 pm The stage structure itself was also able to survive the landing loads. Survive and reuse are two different things. And also, reuse and cost savings are two different things.
Quote from: Lemurion on 05/11/2016 05:38 pmIgnoring the amount of refurbishment required for the moment as that's as much an economic question as a technical one;That's the point. It is a economic question. They could have done it already with no real payload and made the entry of the stage even more benign. And done the reflights with that.
I think there will be no "gas and go" and refurb will always be needed and will be no where close to the savings predicted.
Quote from: jongoff on 05/11/2016 05:53 pmNow, getting Falcon 9 to their mythical 100x reuse level? I'm skeptical as heck about that. But reusing it enough to allow them to offer non-trivial price reductions? That seems pretty likely to me.I believe what they have done up to this point on the design and operation of the vehicle without reuse is a larger impact to the cost of the vehicle than what they will get out of reuse.
Quote from: Jim on 05/11/2016 05:55 pmI believe what they have done up to this point on the design and operation of the vehicle without reuse is a larger impact to the cost of the vehicle than what they will get out of reuse. Hmm... to be honest, I'm not sure whether I agree with this or not. To-date I agree that their design and operations choices have definitely had a larger impact on vehicle cost, and at least near-term that may still be the case. But even without getting into the 100x reuse level, I think they'll get to a point where reuse is making a bigger difference than just their design and operations choices can provide.~Jon
I believe what they have done up to this point on the design and operation of the vehicle without reuse is a larger impact to the cost of the vehicle than what they will get out of reuse.
In addition, I'll add that we've not been hearing about hotfires, so engine issues are also on my "hot list"
I'm not so skeptical, just this isn't the vehicle that will do it. Yes they can launch cheaper, the question is enough cheaper to matter?
Structure that can be reused likely has additional structural margin, if reused a lot, then quite a lot.Is saving this economic or not? Has to prove itself. Hasn't with Shuttle.
So the question might be reframed as "Does it require a larger, more capable RLV to achieve 'gas-n-go' operation?". Would that cause Musk to "go slow" here?Kinda runs counter to Jon's small RLV claims ...
The design and operation choices that SX has made so far clearly have not hurt them. They are producing an expendable LV that has morphed into a plausible reusable first stage. Even in full expendable mode SX has a massive cost advantage on their competition. Are you saying that their quoted price per launch would be perhaps $57 million (full expendable mode) instead of the current $62 million if SX never even bothered with the effort to land the first stage? If their attitude was F9 is a stable platform and they are not doing any more iterations, then overall it would be cheaper?These numbers seem like rounding errors compared to the prices of their competitors.In the big scheme of things, it doesn't seem like it has cost SX much to get to this level of capability. I would be shocked if they have spent more than $50 million on the Grasshopper program, the barges, the labor of the landing effort, etc. They got all of the test landings practically for free by using paying customer launches.
That's not at all what I was trying to say. I was just saying that so far most of the cost savings they've had compared to their competitors has come from design/operations choices, and little so far from reusability, but that I'm optimistic that eventually a larger share of the relative cost savings will start coming from reusability.
Quote from: RocketGoBoom on 05/10/2016 09:09 pm they are going to win a lot of launches after the block buy is over.Not really. Spacex is not going to bend to DOD requirements. They want to keep the F9 generic.
they are going to win a lot of launches after the block buy is over.
Quote from: woods170 on 05/10/2016 05:08 pmWe already know from an earlier removed post (from a ULA employee) that the reuse business-case model posted by another ULA employee is not to be taken seriously. It holds no merit. Besides, the folks here were very good at taking the model apart and exposing the many flaws in it. Can we just forget about it? It's pointless to continue discussing a model that is pretty much useless.Apologies, I wasn't following upthread, I thought I was the first to notice.This was posted by Dr. Sowers though, and he's more than just an employee - he's a high ranking persona there.Not cool, not for him, and not for ULA.EDIT: Fixed spelling
We already know from an earlier removed post (from a ULA employee) that the reuse business-case model posted by another ULA employee is not to be taken seriously. It holds no merit. Besides, the folks here were very good at taking the model apart and exposing the many flaws in it. Can we just forget about it? It's pointless to continue discussing a model that is pretty much useless.
Quote from: Jim on 05/11/2016 04:17 pmQuote from: Lar on 05/11/2016 04:11 pmJim, as of right now, based on what you know, what do you personally think the probability is that SpaceX will fly at least one reused booster at some point? And what do you think the conditional probability of success is, given that they fly one? An educated guess based on little to no data (but arguably more than most of us have) from you would be interesting.From what I saw, the aft end needs much more protection. There were panels that were damaged and opened on the previous booster. The fires on the current booster may have been internal. Careful Jim. You might be giving too much information. Temporary inside insight is good, but you may be walking a red line here....
Would like to point out that all of the structural concerns for recovered boosters as well as most of the retropropulsion plume impingement issues seem to have gone by the wayside.
Quote from: meekGee on 05/10/2016 07:08 pmQuote from: woods170 on 05/10/2016 05:08 pmWe already know from an earlier removed post (from a ULA employee) that the reuse business-case model posted by another ULA employee is not to be taken seriously. It holds no merit. Besides, the folks here were very good at taking the model apart and exposing the many flaws in it. Can we just forget about it? It's pointless to continue discussing a model that is pretty much useless.Apologies, I wasn't following upthread, I thought I was the first to notice.This was posted by Dr. Sowers though, and he's more than just an employee - he's a high ranking persona there.Not cool, not for him, and not for ULA.EDIT: Fixed spellingI agree. It's not cool for Dr. Sowers and ULA to publically post a seriously flawed model and then use it to spread FUD. This was pointed out by the discrediting ULA employee and Lar upthread. Given his senior role within ULA Dr. Sowers really should have known better.