15 ms·

SpaceX set to launch ‘used rocket’

339 points by ethbro 10y ago

aerovistae 10y ago
Fingers crossed. In theory it shouldn't be any more dangerous than a first-time rocket, given that they've examined every inch of it and deemed it flawless. If it weren't flawless, obviously they wouldn't be trying to fly it. So we're just hoping there isn't some unanticipated source of entropy, so to speak. As always.
- nether 10y ago
  Not to be pedantic, but it's not possible to inspect an entire rocket for all defects because so many of them are microscopic and internal (not on the surface of a solid part). These can be analyzed and predicted with fatigue models in aggregate with varying levels of certainty. This comprises the fascinating field of fatigue analysis.
  - aerovistae 10y ago
    You're right, of course. This is what I meant by "unanticipated source of entropy," though -- some form of breakage which is neither visible nor predictable with the available information.
    - nether 10y ago
      Semantics - it is anticipated and quantified, but with error bounds ;)
  - friedman23 10y ago
    It's true that there is fatigue but shouldn't most of the fatigue be mitigated by the fact that they slow the rocket down significantly upon reentry? I don't see why a falcon 9 should suffer much more fatigue than any jet that goes faster than 2x the speed of sound
    - nether 10y ago
      Yes, mitigated compared to a full-speed descent. It's not really possible to compare it to an entirely different system though like a fighter jet. Fatigue is analyzed at a part level, like a single strut or a patch of aluminum reinforcing a small area, and is dependent on the type of loading, materials, magnitude/dir of stress, temps in some cases, frequency of cycles, and so on. Fatigue life in aerospace is a tradeoff between designing heavier, beefier, longer lasting parts and skimpier, lighter parts that lead to a lighter vehicle overall. Any part can undergo fatigue damage for a given loading if it is designed to be weak enough.
    - krastanov 10y ago
      It might not matter after you do the math, but on landing this rocket is plunging back into the atmosphere at supersonic velocity moving through its own rocket exhaust. This is a pretty visceral image that does sound like something causing fatigue.
  - techdragon 10y ago
    There are pretty sophisticated machines out there for non destructive machine inspections. Many based on X-ray or MRI technology depending on the materials. Similar to the machines used to inspect shipping containers. I would not be surprised if SpaceX had at least considered if not obtained equipment for the ability to X-ray the entire assembled rocket for any internal defects. Anyone curious can take a look at the equipment from Yxlon (http://www.yxlon.com http://www.yxlon.com) for examples of COTS X-ray based inspection that's available. And Yxlon and most others in this industry do custom work, making a robotic full sized rocket inspection setup, quite a realistic concept when the costs of failure are considered.
    - nether 10y ago
      Yeah, we used X-ray inspections to get away with smaller safety margins at my last employer. Plastic deformations start at the grain level (nanometers) though, and I don't think there's any X-ray microscopy to do this en masse.
  - SEJeff 10y ago
    While you're correct, you're not pedantic enough. Using X-rays to validate the most critical engine parts has been done for literally years and is a relatively boring and old part of "rocket science". Don't expect SpaceX to spend some serious cash on this and techniques such as this (MRI and sonic / ultrasound tech comes to mind). Source: a good friend of mine is a structural engineer for Aerospace Corporation (a rocket scientist if you will) and I'm an avid r/SpaceX reader.
    - nether 10y ago
      X-ray takes care of macro internal defects. It doesn't reveal defects at the grain (nanometer) scale, outside of research labs. I think it'd be time prohibitive to scan at that resolution for every component of large systems.
    - unwind 10y ago
      Uh, you meant "Don't expect SpaceX not to ...", or "Expect SpaceX to ...", right? I had a negation parse error.
      - SEJeff 10y ago
        Well played sir, well played, and yes! :)
  - usrusr 10y ago
    On the other hand, the same is true about inspecting an entire rocket for manufacturing defects.
- mikeash 10y ago
  It probably isn't there yet, but once they get it figured out, used rockets should be safer. Just think: how comfortable would you be flying on an airliner that has literally never flown before? The SpaceX fan community has taken to calling these rockets "flight proven," and while that might be a bit ambitious today, I think that's a good way to think about where it should end up.
jessriedel 10y ago
As usual, /r/SpaceX is a treasure trove of information about this launch. https://www.reddit.com/r/spacex/comments/62aqi7/rspacex_ses10_official_launch_discussion_updates/ https://www.reddit.com/r/spacex/comments/62aqi7/rspacex_ses1... https://www.reddit.com/r/spacex/ https://www.reddit.com/r/spacex/ Here's the SpaceX press kit: http://www.spacex.com/sites/spacex/files/finalses10presskit.pdf http://www.spacex.com/sites/spacex/files/finalses10presskit....
- H4CK3RM4N 10y ago
  I'm always amazed at how different /r/SpaceX and /r/Tesla are from the rest of Reddit.
  - nickik 10y ago
    There is lots of stuff on reddit. I would not call either of those very out of the norm.
    - jessriedel 10y ago
      Sure there are other good subreddit, but at the level of r/SpaceX? Very curious what those would be.
      - brianwawok 10y ago
        Any deep topic. For example advancedrunning has pro level runners and coaches. Many very niche rabbit holes there..
        jessriedel 10y ago
        A random niche topic is less terrible than r/all, but it is not close to the quality of r/spacex. What specific subreddit reach this level of quality?
        10y ago
the8472 10y ago
It is interesting that they are confident enough to launch it with a commercial payload instead of doing a test flight with a dummy second stage.
- grondilu 10y ago
  IIRC the client gets a significant discount for accepting an experimental launch.
  - jessriedel 10y ago
    > “We got a discount,” Halliwell said. “I can’t go into the specific pricing, but we did get a discount for being an early adopter of the technology.” > In response to a question whether the discount was closer to potential figures publicly disclosed by SpaceX’s Shotwell and SES chief executive Karim Sabbagh — who discussed possible reusability discounts of 30 percent and 50 percent, respectively — Halliwell said: “It certainly came out closer to Gwynne than to Karim.” > The figures, while stated as unofficial and somewhat arbitrary, illustrated the behind-the-scenes negotiation on the real price of a reused Falcon 9. > Halliwell did not confirm whether the ultimate price for the SES 10 launch fell between the 30 percent and 50 percent discount figures. > “We did receive a good discount on the baseline price,” he said. “It’s not as crazy or spectacular as you might think, and that makes sense. SpaceX has to supply an awful lot of equipment, and they have to do an awful lot of refurbishment. > “It is an interesting price, and it’s something which we believe will be meaningful going forward, and will be meaningful for the industry in the longer term,” he said. > SES says there was “no material change” to the insurance coverage or the company’s premium payment after cinching the agreement to launch SES 10 on a “flight-proven” rocket. https://spaceflightnow.com/2016/09/13/ses-stands-by-spacex-after-getting-good-discount-on-reused-rocket/ https://spaceflightnow.com/2016/09/13/ses-stands-by-spacex-a...
    - simonh 10y ago
      > SpaceX has to supply an awful lot of equipment, and they have to do an awful lot of refurbishment. Right, they've already stated that with the current rocket there's no economical way to recover the second stage, which aren't cheap, and so far nobody knows how many launches the cores will be good for. Also the infrastructure for supporting the recovery efforts, including the drone ships and their operations, can't be cheap. I expect the SpaceX re-use project will probably be in the red economically for years before it starts paying off it's setup costs.
blhack 10y ago
Could anybody here comment on the differences between spacex's engine, and the engines on the space shuttle? I was under the impression that SpaceX was trying to make the first re-usable rocket stage, but I've recently found out that that isn't true. The space shuttle already holds that title. I'm also kindof curious why they decided to go with a vertical-landing-design, instead of putting some wings on it and having it glide home like the shuttle did. Is that a weight-concern? Aerodynamics, mabye, but couldn't the wings be articulated in the same way that the landing legs are right now? (I will admit some ignorance in this field. I'm definitely a fan, but I'm definitely not a historian or a rocket scientist)
- icarus_drowning 10y ago
  As I understand it, the main difference is that the Falcon rockets are (or are eventually meant to be) much less dependent on refurbishment between launches. The Space Shuttle required extensive and expensive work between launches to the extent that many critics[1] claimed that it wasn't truly "reusable". (IMHO, while the shuttle program definitely didn't achieve its goals, it seems like calling it "reusable" is fair). As for gliding back: the Falcon booster does not actually achieve orbit-- when the main engine cuts off, it is on a ballistic trajectory back to the ocean. While it may be possible to design some sort of gliding apparatus to "save" a booster on a sub-orbital trajectory, it is (again, as I understand it), much simpler to simply adjust that trajectory via a boostback burn that reverses or slows that trajectory, and to then perform a suicide burn[2] to recover the stage, either on a barge or (on lower orbit missions) back on a land-based pad. I am not a rocket scientist, nor do I have experience in the space industry-- these thoughts are just based on what I've read following the SpaceX reusability program as closely as I can for the past few years. I do play a lot of Kerbal Space Program, though. [1] https://en.wikipedia.org/wiki/Criticism_of_the_Space_Shuttle_program https://en.wikipedia.org/wiki/Criticism_of_the_Space_Shuttle... [2] http://space.stackexchange.com/questions/10307/what-is-a-suicide-burn http://space.stackexchange.com/questions/10307/what-is-a-sui...
  - SEJeff 10y ago
    They also like to call the landing a "hover slam" in that it burns at the very last second and slams down pretty hard.
brogrammer2 10y ago
Hello, If this launch is successful, how much money SpaceX would have saved by using a 'used rocket' instead of a new one?
- Atal 10y ago
  In general they've said that launching used rockets will cost customers about 30 percent less than regular price (so ~43 million instead of 62). For this specific case I wouldn't be surprised if they charged SES less than that because of the risk involved in being the first flight.
- InclinedPlane 10y ago
  It's hard to say but easily tens of millions of dollars. Note that there's little incentive to offer a significantly lower price to customers without any competition applying downward price pressure in that range so it's basically impossible to figure out what the internal cost difference is just by looking at price changes.
- ygra 10y ago
  No one knows for now, as refurbishment costs are a big unknown (and I don't think SpaceX will release those numbers at this point). The cost of the first stage is a significant part of the overall rocket cost, though, considering it's the largest part, and it has 90 % of the engines (each of which costs about a million already). Since they took four months to refurbish this stage it may have cost quite a bit to do so for now. But they're learning and Block 5 to debut later this year will have lots of changes based on what they learned.
  - simonh 10y ago
    In fact optimizing the Falcon 9 for first stage re-use has lead it down a very different development path from most modern launchers. On an expendable architecture the priority is saving weight on the second stage, because every kilogram saved there saves many kilograms for the first stage. So pound for pound the second stage usually costs more than the first stage. Also the cheapest way to build a first stage is with one or just a few big engines. Both these optimization criteria are reversed for a re-usable design. In the Falcon 9 the first stage is re-used while the second stage isn’t, so that’s the stage you want to spend your money on. Also a few big engines can’t be throttled low enough or gimbaled precisely enough for a landing burn. Even the using just one of the relatively small engines in the Falcon 9 can’t be throttled low enough to hover. Hence the Falcon 9 has many smaller engines to give it a much greater range of thrust settings and better attitude control.
andromeda__ 10y ago
The incumbents said it couldn't be done...
- InclinedPlane 10y ago
  It's pretty common for people to make a hard problem out to be much more difficult than it actually is if they have a track record of failing to tackle it. The reality is that the problem is not that terribly difficult, all things considered. That's not to diminish SpaceX's achievement, what they've done is genius. But their genius is primarily in avoiding falling into the common trap of optimizing an expendable rocket to the detriment of any hope of easy and beneficial reuse of part of it. And indeed the most logical optimizations of expendable rockets tend to push the design in precisely that direction, so it takes a considerable amount of sticktoitiveness to avoid that pitfall. Additionally, they figured out how to do reusable R&D very effectively and cheaply (by using commercial launches to subsidize most of the costs). Together this has led them to success, but any space-faring nation or organization with a few billion dollars sitting around could have achieved the same thing, they just didn't have the courage or foresight to do so. Indeed, Blue Origin will probably follow along and reproduce the same achievement in orbital rocketry within the next 5 or 10 years or so. And I expect others to follow as well, once a model that can be easily copied has become established and its advantages proven.
  - ygra 10y ago
    I guess the fact that it hasn't been done so far is in part due to lack of technology (bot materials and processing power) and the lack of necessity. Space programs have been purely national affairs for a long time and cost for the rather few launches was not really an issue. Even more so when the launcher was developed off ICBMs where development costs were already paid for with a military budget. And, well, as long as no cheaper competitor comes along it doesn't matter if launch prices are high since whoever needs to launch something just has to pay them.
    - nickik 10y ago
      Well it was done. The Space Shuttle was this exact idea. The problem was just that it did not work and nobody wanted to try it again.
jlebrech 10y ago
reusability is the key to commodity rockets. look at the car and how depreciation works, people will own a rockets after 5 owners for a ridiculously cheap price. at that point fuel will be the number one cost issue and the fuel source will charge.
- usrusr 10y ago
  Expect used rockets to be about as comparable to used cars as used cars are comparable to used chewing gum.
  - jlebrech 10y ago
    you're right, it'll be companies buying used rockets.
jlebrech 10y ago
methane fuel is what we desperately need now, methane is the number one danger to our atmosphere and burning it is the most ecofriendly way of disposing of it.
- Robotbeat 10y ago
  All the next-generation large American commercial rockets will use methane. United Launch Alliance's Vulcan (15-30 tons payload to low orbit, depending on if solid rocket boosters are added) will, using two of Blue Origin's BE-4 methane engines. Blue Origin's reusable (initially partially, eventually fully reusable) New Glenn (40 tons payload to low orbit) will be using the same engines but 7 of them for the first stage and I think one of them for the second stage. SpaceX's fully reusable ITS (300 tons payload to orbit reusable, 500 tons expendable) will use 42 Raptor engines, full-flow staged combustion engines at ridiculously high chamber pressure. On just the first stage. 9 more Raptor engines on the spaceship portion (which is like a spacecraft/second-stage combination). Additionally, Masten Space Systems is developing a small-sat (1 ton or maybe 300kg, depending on if they're picked under DARPA's XS-1 program) launcher that would be highly reusable called Xepthyr that will use their Broadsword methane engine. BTW, Masten Space Systems actually inspired SpaceX to pursue vertical landing recovery years ago (SpaceX had previously tried using parachutes on Falcon 1 and the Falcon 9 first stages, without success) with this video that Elon Musk reportedly emailed to the whole company: https://www.youtube.com/watch?v=kqm48D5WZ6A https://www.youtube.com/watch?v=kqm48D5WZ6A (And Masten also has been pursuing using a launch cradle instead of legs for landing, similar to what SpaceX pursued for ITS. And I think SpaceX got that idea from Masten, too.)
- simonh 10y ago
  I'm pretty sure any methane fuel they use will be manufactured for the purpose rather than extracted from the atmosphere. That means there's bound to be some leakage.
  - jlebrech 10y ago
    leakage is happenening here http://siberiantimes.com/ecology/casestudy/news/n0681-now-the-proof-permafrost-bubbles-are-leaking-methane-200-times-above-the-norm/ http://siberiantimes.com/ecology/casestudy/news/n0681-now-th... we could extract this before it get's into the atmosphere.
TeMPOraL 10y ago
The BBC article doesn't use the word "today" anywhere in the text, nor does it provide a date. Does "X set to do Y later" in journalism-speak mean "later today" instead of "later somewhen"? Is this another idiosyncrasy like using commas instead of "and"?
- newhere420 10y ago
  In Britain, you commonly use it in that form. For example, we might say "want to do X later?". Perhaps it's just British?
  - freehunter 10y ago
    I feel like it's a little different when you speaking to someone versus in a news article. I could read the article tomorrow and be very confused, but I won't hear you say those words tomorrow unless you actually mean tomorrow.
ivanb 10y ago
When you launch single-use rockets every next one is more advanced and reliable than the previous one. It includes some of the error corrections that were found during previous launches. This is an often ignored point. I highly doubt that reusable rockets would be economically viable at our current state of material technology. We need better materials for the engines and the tanks to make them reusable. Even airplanes have to be retired when they still look new just because they've been through multiple pressurization/depressurization cycles and accumulated microfissures. Of course they are not even close to the levels of stress sustained by rockets.
- artursapek 10y ago
  Airplanes get retired after many uses... so why can't rockets?
- JshWright 10y ago
  I think your point is weakened a bit by the fact that SpaceX is both the only company flying a rocket designed for re-usability, as well as the company that is iterating their design far faster than any of their competitors. SpaceX has had trouble getting approved for Air Force launches in the past because they "tweak" the design of Falcon 9 too often. They had to commit to NASA to fly seven launches of a "fixed" design (what SpaceX is calling "Block 5") before they will be allowed to fly crewed missions (for NASA).
- Voloskaya 10y ago
  > We need better materials for the engines and the tanks to make them reusable. Better than which target? Yes there is a lot of stress, but what make you say with such certainty that the stress levels are not suitable for 2, 3, 10 or 50 launches? Just reusing a rocket a single time would be a huge cost saver. I don't see how this is not "economically viable". > When you launch single-use rockets every next one is more advanced and reliable than the previous one Let's not forget that we have been using russian engines build in 1960 and stored in a hangar for decades in siberia on the Atlas and Antares...
- simonh 10y ago
  >I highly doubt that reusable rockets would be economically viable at our current state of material technology. Well, we're about to find out for sure later today, bar a scrubbed launch.
benmorris 10y ago
I'm pretty stoked we are staying right next to Jeti park on spring break and are planning on watching this launch tonight from the beach. We've got to see one other Delta IV launch, but really looking forward to seeing this one. We just missed OCSILY heading out to landing zone, but I got a good view of the parking spot and unloading area.
woodandsteel 10y ago
Looks like SpaceX is going to sell the rocket: https://losangeles.craigslist.org/lac/for/6067287590.html https://losangeles.craigslist.org/lac/for/6067287590.html

339 points by ethbro 10y ago

Fingers crossed. In theory it shouldn't be any more dangerous than a first-time rocket, given that they've examined every inch of it and deemed it flawless. If it weren't flawless, obviously they wouldn't be trying to fly it. So we're just hoping there isn't some unanticipated source of entropy, so to speak. As always.

nether 10y ago
Not to be pedantic, but it's not possible to inspect an entire rocket for all defects because so many of them are microscopic and internal (not on the surface of a solid part). These can be analyzed and predicted with fatigue models in aggregate with varying levels of certainty. This comprises the fascinating field of fatigue analysis.
- aerovistae 10y ago
  You're right, of course. This is what I meant by "unanticipated source of entropy," though -- some form of breakage which is neither visible nor predictable with the available information.
  - nether 10y ago
    Semantics - it is anticipated and quantified, but with error bounds ;)
- friedman23 10y ago
  It's true that there is fatigue but shouldn't most of the fatigue be mitigated by the fact that they slow the rocket down significantly upon reentry? I don't see why a falcon 9 should suffer much more fatigue than any jet that goes faster than 2x the speed of sound
  - nether 10y ago
    Yes, mitigated compared to a full-speed descent. It's not really possible to compare it to an entirely different system though like a fighter jet. Fatigue is analyzed at a part level, like a single strut or a patch of aluminum reinforcing a small area, and is dependent on the type of loading, materials, magnitude/dir of stress, temps in some cases, frequency of cycles, and so on. Fatigue life in aerospace is a tradeoff between designing heavier, beefier, longer lasting parts and skimpier, lighter parts that lead to a lighter vehicle overall. Any part can undergo fatigue damage for a given loading if it is designed to be weak enough.
  - krastanov 10y ago
    It might not matter after you do the math, but on landing this rocket is plunging back into the atmosphere at supersonic velocity moving through its own rocket exhaust. This is a pretty visceral image that does sound like something causing fatigue.
- techdragon 10y ago
  There are pretty sophisticated machines out there for non destructive machine inspections. Many based on X-ray or MRI technology depending on the materials. Similar to the machines used to inspect shipping containers. I would not be surprised if SpaceX had at least considered if not obtained equipment for the ability to X-ray the entire assembled rocket for any internal defects. Anyone curious can take a look at the equipment from Yxlon (http://www.yxlon.com http://www.yxlon.com) for examples of COTS X-ray based inspection that's available. And Yxlon and most others in this industry do custom work, making a robotic full sized rocket inspection setup, quite a realistic concept when the costs of failure are considered.
  - nether 10y ago
    Yeah, we used X-ray inspections to get away with smaller safety margins at my last employer. Plastic deformations start at the grain level (nanometers) though, and I don't think there's any X-ray microscopy to do this en masse.
- SEJeff 10y ago
  While you're correct, you're not pedantic enough. Using X-rays to validate the most critical engine parts has been done for literally years and is a relatively boring and old part of "rocket science". Don't expect SpaceX to spend some serious cash on this and techniques such as this (MRI and sonic / ultrasound tech comes to mind). Source: a good friend of mine is a structural engineer for Aerospace Corporation (a rocket scientist if you will) and I'm an avid r/SpaceX reader.
  - nether 10y ago
    X-ray takes care of macro internal defects. It doesn't reveal defects at the grain (nanometer) scale, outside of research labs. I think it'd be time prohibitive to scan at that resolution for every component of large systems.
  - unwind 10y ago
    Uh, you meant "Don't expect SpaceX not to ...", or "Expect SpaceX to ...", right? I had a negation parse error.
    - SEJeff 10y ago
      Well played sir, well played, and yes! :)
- usrusr 10y ago
  On the other hand, the same is true about inspecting an entire rocket for manufacturing defects.
mikeash 10y ago
It probably isn't there yet, but once they get it figured out, used rockets should be safer. Just think: how comfortable would you be flying on an airliner that has literally never flown before? The SpaceX fan community has taken to calling these rockets "flight proven," and while that might be a bit ambitious today, I think that's a good way to think about where it should end up.

jessriedel 10y ago

As usual, /r/SpaceX is a treasure trove of information about this launch. https://www.reddit.com/r/spacex/comments/62aqi7/rspacex_ses10_official_launch_discussion_updates/ https://www.reddit.com/r/spacex/comments/62aqi7/rspacex_ses1... https://www.reddit.com/r/spacex/ https://www.reddit.com/r/spacex/ Here's the SpaceX press kit: http://www.spacex.com/sites/spacex/files/finalses10presskit.pdf http://www.spacex.com/sites/spacex/files/finalses10presskit....

H4CK3RM4N 10y ago
I'm always amazed at how different /r/SpaceX and /r/Tesla are from the rest of Reddit.
- nickik 10y ago
  There is lots of stuff on reddit. I would not call either of those very out of the norm.
  - jessriedel 10y ago
    Sure there are other good subreddit, but at the level of r/SpaceX? Very curious what those would be.
    - brianwawok 10y ago
      Any deep topic. For example advancedrunning has pro level runners and coaches. Many very niche rabbit holes there..
      - jessriedel 10y ago
        A random niche topic is less terrible than r/all, but it is not close to the quality of r/spacex. What specific subreddit reach this level of quality?
        10y ago

the8472 10y ago

It is interesting that they are confident enough to launch it with a commercial payload instead of doing a test flight with a dummy second stage.

grondilu 10y ago
IIRC the client gets a significant discount for accepting an experimental launch.
- jessriedel 10y ago
  > “We got a discount,” Halliwell said. “I can’t go into the specific pricing, but we did get a discount for being an early adopter of the technology.” > In response to a question whether the discount was closer to potential figures publicly disclosed by SpaceX’s Shotwell and SES chief executive Karim Sabbagh — who discussed possible reusability discounts of 30 percent and 50 percent, respectively — Halliwell said: “It certainly came out closer to Gwynne than to Karim.” > The figures, while stated as unofficial and somewhat arbitrary, illustrated the behind-the-scenes negotiation on the real price of a reused Falcon 9. > Halliwell did not confirm whether the ultimate price for the SES 10 launch fell between the 30 percent and 50 percent discount figures. > “We did receive a good discount on the baseline price,” he said. “It’s not as crazy or spectacular as you might think, and that makes sense. SpaceX has to supply an awful lot of equipment, and they have to do an awful lot of refurbishment. > “It is an interesting price, and it’s something which we believe will be meaningful going forward, and will be meaningful for the industry in the longer term,” he said. > SES says there was “no material change” to the insurance coverage or the company’s premium payment after cinching the agreement to launch SES 10 on a “flight-proven” rocket. https://spaceflightnow.com/2016/09/13/ses-stands-by-spacex-after-getting-good-discount-on-reused-rocket/ https://spaceflightnow.com/2016/09/13/ses-stands-by-spacex-a...
  - simonh 10y ago
    > SpaceX has to supply an awful lot of equipment, and they have to do an awful lot of refurbishment. Right, they've already stated that with the current rocket there's no economical way to recover the second stage, which aren't cheap, and so far nobody knows how many launches the cores will be good for. Also the infrastructure for supporting the recovery efforts, including the drone ships and their operations, can't be cheap. I expect the SpaceX re-use project will probably be in the red economically for years before it starts paying off it's setup costs.

blhack 10y ago

Could anybody here comment on the differences between spacex's engine, and the engines on the space shuttle? I was under the impression that SpaceX was trying to make the first re-usable rocket stage, but I've recently found out that that isn't true. The space shuttle already holds that title. I'm also kindof curious why they decided to go with a vertical-landing-design, instead of putting some wings on it and having it glide home like the shuttle did. Is that a weight-concern? Aerodynamics, mabye, but couldn't the wings be articulated in the same way that the landing legs are right now? (I will admit some ignorance in this field. I'm definitely a fan, but I'm definitely not a historian or a rocket scientist)

icarus_drowning 10y ago
As I understand it, the main difference is that the Falcon rockets are (or are eventually meant to be) much less dependent on refurbishment between launches. The Space Shuttle required extensive and expensive work between launches to the extent that many critics[1] claimed that it wasn't truly "reusable". (IMHO, while the shuttle program definitely didn't achieve its goals, it seems like calling it "reusable" is fair). As for gliding back: the Falcon booster does not actually achieve orbit-- when the main engine cuts off, it is on a ballistic trajectory back to the ocean. While it may be possible to design some sort of gliding apparatus to "save" a booster on a sub-orbital trajectory, it is (again, as I understand it), much simpler to simply adjust that trajectory via a boostback burn that reverses or slows that trajectory, and to then perform a suicide burn[2] to recover the stage, either on a barge or (on lower orbit missions) back on a land-based pad. I am not a rocket scientist, nor do I have experience in the space industry-- these thoughts are just based on what I've read following the SpaceX reusability program as closely as I can for the past few years. I do play a lot of Kerbal Space Program, though. [1] https://en.wikipedia.org/wiki/Criticism_of_the_Space_Shuttle_program https://en.wikipedia.org/wiki/Criticism_of_the_Space_Shuttle... [2] http://space.stackexchange.com/questions/10307/what-is-a-suicide-burn http://space.stackexchange.com/questions/10307/what-is-a-sui...
- SEJeff 10y ago
  They also like to call the landing a "hover slam" in that it burns at the very last second and slams down pretty hard.

brogrammer2 10y ago

Hello, If this launch is successful, how much money SpaceX would have saved by using a 'used rocket' instead of a new one?

Atal 10y ago
In general they've said that launching used rockets will cost customers about 30 percent less than regular price (so ~43 million instead of 62). For this specific case I wouldn't be surprised if they charged SES less than that because of the risk involved in being the first flight.
InclinedPlane 10y ago
It's hard to say but easily tens of millions of dollars. Note that there's little incentive to offer a significantly lower price to customers without any competition applying downward price pressure in that range so it's basically impossible to figure out what the internal cost difference is just by looking at price changes.
ygra 10y ago
No one knows for now, as refurbishment costs are a big unknown (and I don't think SpaceX will release those numbers at this point). The cost of the first stage is a significant part of the overall rocket cost, though, considering it's the largest part, and it has 90 % of the engines (each of which costs about a million already). Since they took four months to refurbish this stage it may have cost quite a bit to do so for now. But they're learning and Block 5 to debut later this year will have lots of changes based on what they learned.
- simonh 10y ago
  In fact optimizing the Falcon 9 for first stage re-use has lead it down a very different development path from most modern launchers. On an expendable architecture the priority is saving weight on the second stage, because every kilogram saved there saves many kilograms for the first stage. So pound for pound the second stage usually costs more than the first stage. Also the cheapest way to build a first stage is with one or just a few big engines. Both these optimization criteria are reversed for a re-usable design. In the Falcon 9 the first stage is re-used while the second stage isn’t, so that’s the stage you want to spend your money on. Also a few big engines can’t be throttled low enough or gimbaled precisely enough for a landing burn. Even the using just one of the relatively small engines in the Falcon 9 can’t be throttled low enough to hover. Hence the Falcon 9 has many smaller engines to give it a much greater range of thrust settings and better attitude control.

andromeda__ 10y ago

The incumbents said it couldn't be done...

InclinedPlane 10y ago
It's pretty common for people to make a hard problem out to be much more difficult than it actually is if they have a track record of failing to tackle it. The reality is that the problem is not that terribly difficult, all things considered. That's not to diminish SpaceX's achievement, what they've done is genius. But their genius is primarily in avoiding falling into the common trap of optimizing an expendable rocket to the detriment of any hope of easy and beneficial reuse of part of it. And indeed the most logical optimizations of expendable rockets tend to push the design in precisely that direction, so it takes a considerable amount of sticktoitiveness to avoid that pitfall. Additionally, they figured out how to do reusable R&D very effectively and cheaply (by using commercial launches to subsidize most of the costs). Together this has led them to success, but any space-faring nation or organization with a few billion dollars sitting around could have achieved the same thing, they just didn't have the courage or foresight to do so. Indeed, Blue Origin will probably follow along and reproduce the same achievement in orbital rocketry within the next 5 or 10 years or so. And I expect others to follow as well, once a model that can be easily copied has become established and its advantages proven.
- ygra 10y ago
  I guess the fact that it hasn't been done so far is in part due to lack of technology (bot materials and processing power) and the lack of necessity. Space programs have been purely national affairs for a long time and cost for the rather few launches was not really an issue. Even more so when the launcher was developed off ICBMs where development costs were already paid for with a military budget. And, well, as long as no cheaper competitor comes along it doesn't matter if launch prices are high since whoever needs to launch something just has to pay them.
  - nickik 10y ago
    Well it was done. The Space Shuttle was this exact idea. The problem was just that it did not work and nobody wanted to try it again.

jlebrech 10y ago

reusability is the key to commodity rockets. look at the car and how depreciation works, people will own a rockets after 5 owners for a ridiculously cheap price. at that point fuel will be the number one cost issue and the fuel source will charge.

usrusr 10y ago
Expect used rockets to be about as comparable to used cars as used cars are comparable to used chewing gum.
- jlebrech 10y ago
  you're right, it'll be companies buying used rockets.

jlebrech 10y ago

methane fuel is what we desperately need now, methane is the number one danger to our atmosphere and burning it is the most ecofriendly way of disposing of it.

Robotbeat 10y ago
All the next-generation large American commercial rockets will use methane. United Launch Alliance's Vulcan (15-30 tons payload to low orbit, depending on if solid rocket boosters are added) will, using two of Blue Origin's BE-4 methane engines. Blue Origin's reusable (initially partially, eventually fully reusable) New Glenn (40 tons payload to low orbit) will be using the same engines but 7 of them for the first stage and I think one of them for the second stage. SpaceX's fully reusable ITS (300 tons payload to orbit reusable, 500 tons expendable) will use 42 Raptor engines, full-flow staged combustion engines at ridiculously high chamber pressure. On just the first stage. 9 more Raptor engines on the spaceship portion (which is like a spacecraft/second-stage combination). Additionally, Masten Space Systems is developing a small-sat (1 ton or maybe 300kg, depending on if they're picked under DARPA's XS-1 program) launcher that would be highly reusable called Xepthyr that will use their Broadsword methane engine. BTW, Masten Space Systems actually inspired SpaceX to pursue vertical landing recovery years ago (SpaceX had previously tried using parachutes on Falcon 1 and the Falcon 9 first stages, without success) with this video that Elon Musk reportedly emailed to the whole company: https://www.youtube.com/watch?v=kqm48D5WZ6A https://www.youtube.com/watch?v=kqm48D5WZ6A (And Masten also has been pursuing using a launch cradle instead of legs for landing, similar to what SpaceX pursued for ITS. And I think SpaceX got that idea from Masten, too.)
simonh 10y ago
I'm pretty sure any methane fuel they use will be manufactured for the purpose rather than extracted from the atmosphere. That means there's bound to be some leakage.
- jlebrech 10y ago
  leakage is happenening here http://siberiantimes.com/ecology/casestudy/news/n0681-now-the-proof-permafrost-bubbles-are-leaking-methane-200-times-above-the-norm/ http://siberiantimes.com/ecology/casestudy/news/n0681-now-th... we could extract this before it get's into the atmosphere.

TeMPOraL 10y ago

The BBC article doesn't use the word "today" anywhere in the text, nor does it provide a date. Does "X set to do Y later" in journalism-speak mean "later today" instead of "later somewhen"? Is this another idiosyncrasy like using commas instead of "and"?

newhere420 10y ago
In Britain, you commonly use it in that form. For example, we might say "want to do X later?". Perhaps it's just British?
- freehunter 10y ago
  I feel like it's a little different when you speaking to someone versus in a news article. I could read the article tomorrow and be very confused, but I won't hear you say those words tomorrow unless you actually mean tomorrow.

ivanb 10y ago

When you launch single-use rockets every next one is more advanced and reliable than the previous one. It includes some of the error corrections that were found during previous launches. This is an often ignored point. I highly doubt that reusable rockets would be economically viable at our current state of material technology. We need better materials for the engines and the tanks to make them reusable. Even airplanes have to be retired when they still look new just because they've been through multiple pressurization/depressurization cycles and accumulated microfissures. Of course they are not even close to the levels of stress sustained by rockets.

artursapek 10y ago
Airplanes get retired after many uses... so why can't rockets?
JshWright 10y ago
I think your point is weakened a bit by the fact that SpaceX is both the only company flying a rocket designed for re-usability, as well as the company that is iterating their design far faster than any of their competitors. SpaceX has had trouble getting approved for Air Force launches in the past because they "tweak" the design of Falcon 9 too often. They had to commit to NASA to fly seven launches of a "fixed" design (what SpaceX is calling "Block 5") before they will be allowed to fly crewed missions (for NASA).
Voloskaya 10y ago
> We need better materials for the engines and the tanks to make them reusable. Better than which target? Yes there is a lot of stress, but what make you say with such certainty that the stress levels are not suitable for 2, 3, 10 or 50 launches? Just reusing a rocket a single time would be a huge cost saver. I don't see how this is not "economically viable". > When you launch single-use rockets every next one is more advanced and reliable than the previous one Let's not forget that we have been using russian engines build in 1960 and stored in a hangar for decades in siberia on the Atlas and Antares...
simonh 10y ago
>I highly doubt that reusable rockets would be economically viable at our current state of material technology. Well, we're about to find out for sure later today, bar a scrubbed launch.

benmorris 10y ago

I'm pretty stoked we are staying right next to Jeti park on spring break and are planning on watching this launch tonight from the beach. We've got to see one other Delta IV launch, but really looking forward to seeing this one. We just missed OCSILY heading out to landing zone, but I got a good view of the parking spot and unloading area.

woodandsteel 10y ago

Looks like SpaceX is going to sell the rocket: https://losangeles.craigslist.org/lac/for/6067287590.html https://losangeles.craigslist.org/lac/for/6067287590.html