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posted by Fnord666 on Sunday January 14 2018, @06:53PM   Printer-friendly [Skip to comment(s)]
from the space-is-risky dept.

Safety panel raises concerns about Falcon 9 pressure vessel for commercial crew missions

An independent safety panel recommended NASA not certify SpaceX's commercial crew system until the agency better understands the behavior of pressure vessels linked to a Falcon 9 failure in 2016. That recommendation was one of the stronger items in the annual report of the Aerospace Safety Advisory Panel (ASAP) released by NASA Jan. 11, which found that NASA was generally managing risk well on its various programs.

The report devoted a section to the composite overwrapped pressure vessels (COPVs) used to store helium in the second stage propellant tanks of the Falcon 9. The investigation into the September 2016 pad explosion that destroyed a Falcon 9 while being prepared for a static-fire test concluded that liquid oxygen in the tank got trapped between the COPV overwrap and liner and then ignited through friction or other mechanisms.

SpaceX has since changed its loading processes to avoid exposing the COPVs to similar conditions, but also agreed with NASA to redesign the COPV to reduce the risk for crewed launches. NASA has since started a "rigorous test program" to understand how the redesigned COPV behaves when exposed to liquid oxygen, the report stated. ASAP argued that completing those tests is essential before NASA can allow its astronauts to launch on the Falcon 9. "In our opinion, adequate understanding of the COPV behavior in cryogenic oxygen is an absolutely essential precursor to potential certification for human space flight," the report stated, a sentence italicized for emphasis in the report.

[...] The report raised issues in general about the commercial crew program, including concerns that neither Boeing nor SpaceX, the two companies developing vehicles to transport NASA astronauts to and from the International Space Station, will meet a requirement of no greater than a 1-in-270 "loss of crew" (LOC) risk of an accident that causes death or serious injury to a crewmember. That includes, the report stated, a risk of no more than 1 in 500 for launch and reentry.

Both programs are likely to be delayed:

Boeing, SpaceX have razor-thin margins to fly crew missions in 2018


Original Submission

Related Stories

NASA Names First Astronauts to Fly on American Spacecraft; SpaceX Poised to Fly Crew Before Boeing 17 comments

NASA Announces Astronauts for First Commercial Crew Missions

Today, NASA announced the astronaut selection for the first Commercial Crew flights, which will finally restore the ability to launch astronauts from American soil. Boeing's first test flight, which is scheduled for mid-2019, will have Eric Boe, social media-savvy astronaut Chris Ferguson and rookie Nicole Aunapu Mann on board. SpaceX's inaugural Crew Dragon voyage, targeting April 2019, will have Victor Glover and Mike Hopkins as crew.

NASA also announced the astronauts for the first missions, which will be long-duration and dock with the International Space Station. Suni Williams, who is best known for running the Boston Marathon on an ISS treadmill, will be joined by rookie astronaut Josh Cassada. And finally, the second SpaceX demo flight will be crewed by Bob Behnken and Doug Hurley.

Source: Engadget

NASA Names First Astronauts to Fly on American Spacecraft; SpaceX Poised to Fly Crew Before Boeing

NASA has selected nine American astronauts who will fly on SpaceX's Crew Dragon and Boeing's CST-100 Starliner:

President Trump Praises Falcon Heavy, Diminishes NASA's SLS Effort 65 comments

Trump on Falcon Heavy: "I'm so used to hearing different numbers with NASA"

During a cabinet meeting on Thursday inside the White House, President Donald Trump called attention to several model rockets on the table before him. They included an Atlas V, a Falcon 9, a Space Launch System, and more. The president seemed enthused to see the launch vehicles. "Before me are some rocket ships," the president said. "You haven't seen that for this country in a long time."

Then, in remarks probably best characterized as spur of the moment, the president proceeded to absolutely demolish the government's own effort to build rockets by noting the recent launch of the Falcon Heavy rocket. He cited the cost as $80 million. (The list price on SpaceX's website is $90 million.)

"I noticed the prices of the last one they say cost $80 million," Trump said. "If the government did it, the same thing would have cost probably 40 or 50 times that amount of money. I mean literally. When I heard $80 million, I'm so used to hearing different numbers with NASA.''

NASA has not, in fact, set a price for flying the SLS rocket. But Ars has previously estimated that, including the billions of dollars in development cost, the per-flight fees for the SLS rocket will probably be close to $3 billion. Indeed, the development costs of SLS and its ground systems between now and its first flight could purchase 86 launches of the privately developed Falcon Heavy rocket. So President Trump's estimate of NASA's costs compared to private industry does not appear to be wildly off the mark.

[*] SLS: Space Launch System

Related: Maiden Flight of the Space Launch System Delayed to 2019
WFIRST Space Observatory Could be Scaled Back Due to Costs
Safety Panel Raises Concerns Over SpaceX and Boeing Commercial Crew Plans
After the Falcon Heavy Launch, Time to Defund the Space Launch System?
Trump Administration Budget Proposal Would Cancel WFIRST
Leaning Tower of NASA
NASA Moving to Scale Back the Space Technology Mission Directorate


Original Submission

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  • (Score: -1, Troll) by Anonymous Coward on Sunday January 14 2018, @07:03PM

    by Anonymous Coward on Sunday January 14 2018, @07:03PM (#622234)

    Dang dat gummint be meddlin in our capitalist progress! Nossir deez dee lays will not stand!

  • (Score: 5, Interesting) by bradley13 on Sunday January 14 2018, @07:14PM (26 children)

    by bradley13 (3053) Subscriber Badge on Sunday January 14 2018, @07:14PM (#622237) Homepage Journal

    "a risk of no more than 1 in 500 for launch and reentry."

    This is the problem. Western society has become totally risk averse. An astronaut flies a mission, what, once every two years? So assuming a 20 year career, that means at most 10 missions? So they are aiming for less than 2% mortality over the course of a career. That puts them in roughly the same danger category as farmers.

    That's too damned safe. This is a huge part of what makes spaceflight too expensive. This is why we are not making any progress. Imagine pioneers in earlier ages saying to themselves "oh dear, we can't go, it might be dangerous" - we would all still be living in stick huts in Africa.

    What will happen, of course, is that some other country - likely China at this point - will see the potential of owning the high ground, and will get serious about space exploitation. There are more than enough people willing to risk their lives on new frontiers - there always have been. The West will be left wondering what happened. Sort of like the once-great British empire, and the rather pathetic little country that is now talking about banning kitchen knives [express.co.uk] as too dangerous.

    --
    Everyone is somebody else's weirdo.
    • (Score: 0) by Anonymous Coward on Sunday January 14 2018, @07:29PM

      by Anonymous Coward on Sunday January 14 2018, @07:29PM (#622243)

      still be living in stick huts in Africa.

      Africans are wiser than you because all they need do to get technology is sit and wait for busy fools to invent it for them.

    • (Score: 4, Insightful) by frojack on Sunday January 14 2018, @08:04PM (17 children)

      by frojack (1554) Subscriber Badge on Sunday January 14 2018, @08:04PM (#622255) Journal

      Too damned safe?

      1 in 500 is worse odds [fool.com] and Airforce or Navy combat pilots face, and higher than all combat deaths. Almost every other job death rate is measured in deaths per 100,000 workers.

      SpaceX has spent more time perfecting rocket return and landing than safe crew delivery.

      Half the people here just hand waive into existence the ability to land on mars, mine the asteroids, build colonies on the moon.

      A no greater than a 1-in-270 "loss of crew" is a ridiculously low bar for a profession some people around here insist must become commonplace.

      --
      No, you are mistaken. I've always had this sig.
      • (Score: 4, Insightful) by takyon on Sunday January 14 2018, @08:12PM (2 children)

        by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Sunday January 14 2018, @08:12PM (#622256) Journal

        Can these odds even be effectively measured? Most space accidents seem to be caused by one-time design problems which are discovered and fixed in the aftermath. The low launch rate (of an individual rocket+spacecraft, or the industry overall) contributes to the uncertainty. Previous accidents hurt the record (SpaceX's two worst explosions get brought up constantly) but make future craft safer.

        What could be safer? Single-stage-to-orbit spaceplanes? Abandonment of chemical rockets altogether in some EmDrive/stolen UFO scenario?

        --
        [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
        • (Score: 2, Interesting) by tftp on Sunday January 14 2018, @09:22PM (1 child)

          by tftp (806) on Sunday January 14 2018, @09:22PM (#622273) Homepage

          Abandonment of chemical rockets altogether in some EmDrive/stolen UFO scenario?

          Something like that. Chemical rockets are a dead end anyway because they are too inefficient and too expensive. They are dangerous because we have to work with huge energies that are contained in materials that are unsafe even on their own. Spaceflight on chemical rockets cannot become a path to somewhere for the people. It can be only a narrow, dangerous road for researchers who don't mind sitting atop a flying bomb.

          Would be nice to have an elevator to orbit, but chances are that we won't be capable of producing and installing it until we don't need it.

          If we do not invent the technologies to, say, fly within the gravity field of the planet, we have little chance of conquering other planets. Other worlds are large planets, and there will be only few teams on them. They will need a flying vehicle that can fly half the planet on single tank of fuel, hover and land anywhere (VTOL) and be very reliable. No service for tens of flights! Of course, it should not depend on atmosphere - even in our system we have quite a variety of those. People say that the martian colony starts with a base, and then sends crawlers with scientists up to several thousand miles away. Aside from lack of such efficient machines, those crews are playing with death. There are no comm or gps sats around Mars and no plans to deploy them. There is no (?) ionosphere that supports SW hops. UHF goes straight through. How will they call for help? How soon they will be saved? This is why flying vehicles are essential for study of a planet. They also cover huge distances that no crawler can.

          As it stands, all current plans of manned presence in space resemble ill equipped individuals, alone attacking Everest. This rarely works. Sensible space exploration requires many technologies (robots, engines, controlled fusion) that we do not have yet. It only makes sense to go back to the drawing board and invent what we need rather than to pave the planets with dead bodies of pioneers. There is no emergency, Moon and Mars aren't going anywhere in nearest 100 years. There is no benefit trying to set up there right now.

          • (Score: 1, Troll) by Ethanol-fueled on Sunday January 14 2018, @10:54PM

            by Ethanol-fueled (2792) on Sunday January 14 2018, @10:54PM (#622307) Homepage

            The problem was that these are California hipsters we're dealing with and they think that carbon fiber is the solution to all of their problems just because their yuppie bicycles and twice-used stand-up paddleboards have the carbon fiber wrap.

      • (Score: 1) by khallow on Sunday January 14 2018, @09:05PM (13 children)

        by khallow (3766) Subscriber Badge on Sunday January 14 2018, @09:05PM (#622269) Journal
        Doesn't make sense to speak of such odds for a vehicle that probably won't fly 500 times. For example, if your vehicle only flies 20 times, then there could be a 5% loss of crew risk in there and you wouldn't know of it due to just being lucky. Meanwhile flying 500 times and not seeing loss of crew due to said 5% risk is luck on the order of winning lotteries.
        • (Score: 0) by Anonymous Coward on Sunday January 14 2018, @10:54PM (6 children)

          by Anonymous Coward on Sunday January 14 2018, @10:54PM (#622308)

          So the 50/50 odds for a coin toss don't make any sense unless we are going to sit there and flip the damn coin one hundred times? Methinks someone is lacking a basic understanding of probability.

          • (Score: 4, Touché) by takyon on Sunday January 14 2018, @11:31PM

            by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Sunday January 14 2018, @11:31PM (#622318) Journal

            1. We don't know the real odds before it launches.
            2. It won't launch often enough for us to determine the real odds. Space Launch System has 12 planned launches [wikipedia.org] over a 14 year period. Only 7 of them will be crewed, and three of the launches will be on the second main variant of the design, Block 2. There's probably not enough coin flips for disaster to strike.

            --
            [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
          • (Score: 3, Informative) by khallow on Monday January 15 2018, @12:47AM (4 children)

            by khallow (3766) Subscriber Badge on Monday January 15 2018, @12:47AM (#622337) Journal
            You don't understand the problem. An assertion has been made about the reliability of the coin. How do you check that the assertion is correct - particularly when cutting corners and deception can be involved? N coin tosses would be enough to verify the coin is with about 100%/sqrt(N) of 50%, so a range of 40% to 60%. To get the bias of the coin to within 1 in 500 throws, you need roughly 500^2 = 250,000 throws to confirm that the bias is within the desired range.

            As to manned space flight, it hasn't happened often enough to bother with a 1 in 500 LOC rate. We've only had 320 crewed launches since the beginning of space exploration. There is no basis for asserting such a high reliability. We could, for example, have several 1 in 500 LOC risks that apply to every manned launch ever made, that just haven't happened yet. In the face of that level of ignorance, it makes no sense to demand high standards of reliability.
            • (Score: 4, Interesting) by JoeMerchant on Monday January 15 2018, @04:58AM (3 children)

              by JoeMerchant (3937) on Monday January 15 2018, @04:58AM (#622431)

              You're right that we're ignorant of the "true" (better stated as "statistically reliable") rates of failure in use: insufficient data.

              You're wrong that attempting to design for high standards of reliability is senseless. It's quite expensive to train new astronauts and build replacement vehicles, not to mention politically difficult to fund a program that makes us look foolish and incompetent.

              When there's insufficient test-trial data to base failure rate analysis on, the engineers pull numbers out of any convenient orifice and throw them into a risk management table - in med devices there's a whole standardized ISO procedure for doing just that. The "guess" numbers are tossed around between the best experts available until they reach consensus - the process is documented as a design review, and we move on to the next problem. I imagine in NASA's manned programs they include such available data as they have to inform their guesses. You'd be surprised at just how valuable these risk management processes turn out to be, even when the best experts available can't point to massive records of previous experience.

              Even the Space Shuttle managed to successfully take off and land in 132 of 134 tries. You don't get to that level of reliability without designing for it.

              --
              Україна не входить до складу Росії.
              • (Score: 1) by khallow on Monday January 15 2018, @07:53AM (2 children)

                by khallow (3766) Subscriber Badge on Monday January 15 2018, @07:53AM (#622488) Journal

                You're wrong that attempting to design for high standards of reliability is senseless. It's quite expensive to train new astronauts and build replacement vehicles, not to mention politically difficult to fund a program that makes us look foolish and incompetent.

                It can be worse than senseless. For example, such design can actually introduce risks that are higher than the ones that the effort is trying to reduce. It can also create moral hazards and other systemic or behavior problems that increase risk.

                Even the Space Shuttle managed to successfully take off and land in 132 of 134 tries. You don't get to that level of reliability without designing for it.

                And having a few dozen manned launches already under one's belt.

                • (Score: 0) by Anonymous Coward on Monday January 15 2018, @08:40AM (1 child)

                  by Anonymous Coward on Monday January 15 2018, @08:40AM (#622490)

                  t can also create moral hazards

                  Say what?
                  And you didn't even mentioned ethical hazards.

                  • (Score: 1) by khallow on Monday January 15 2018, @07:02PM

                    by khallow (3766) Subscriber Badge on Monday January 15 2018, @07:02PM (#622665) Journal
                    It's an economics term and while it has some relevance to morality and ethics, it's just a label. Moral hazard [wikipedia.org] means merely that when someone is protected from the consequences of risk, they tend to engage in riskier behavior. For example, people who drive rental cars tend to be more careless with them than if they were their own cars. The consequences of minor scratches and dings are far less significant when one doesn't have to look at it for years or pay for repairs. In turn, this creates elevated risks for the party that intentionally rents out these vehicles. The moral hazard isn't for the driver, but for the rental business (and perhaps the outside world) that is subject to these increased risks.
        • (Score: 2) by frojack on Monday January 15 2018, @01:25AM (5 children)

          by frojack (1554) Subscriber Badge on Monday January 15 2018, @01:25AM (#622356) Journal

          20 times?

          There were 135 space shuttle missions. About 146 Soyuz missions counting all Soyuz models.
          With SpaceX bringing the price of a launch down you can expect the capsules being developed now to have a long service life, including flying multiple missions in the same vehicle.

          Just after the Challenger disaster the entire US space program had a 4% fatality rating, which quickly dropped until the Columbia ramped it up again. Its been declining ever since.

          The only reason NASA want's to restrict commercial providers to no better than 1 in 270, is that is just about their overall record.

          --
          No, you are mistaken. I've always had this sig.
          • (Score: 2, Interesting) by khallow on Monday January 15 2018, @02:38AM (4 children)

            by khallow (3766) Subscriber Badge on Monday January 15 2018, @02:38AM (#622374) Journal
            It's an example. NASA has had 171 manned missions since the beginning, 2 which resulted in loss of crew. That's nowhere near 1 in 270.
            • (Score: 0) by Anonymous Coward on Monday January 15 2018, @05:12AM (3 children)

              by Anonymous Coward on Monday January 15 2018, @05:12AM (#622435)

              2 which resulted in loss of crew. That's nowhere near 1 in 270.

              Apollo 1 doesn't count, I guess?

              • (Score: 1) by khallow on Monday January 15 2018, @06:45AM (2 children)

                by khallow (3766) Subscriber Badge on Monday January 15 2018, @06:45AM (#622472) Journal

                Apollo 1 doesn't count, I guess?

                Correct, it wasn't a launch.

                • (Score: 2) by choose another one on Monday January 15 2018, @09:22AM

                  by choose another one (515) Subscriber Badge on Monday January 15 2018, @09:22AM (#622499)

                  Correct, it wasn't a launch.

                  Umm, nor was the SpaceX COPV explosion being talked about in TFA - it was during fueling for static fire test.

                  If we don't count pre-launch failures on the pad then SpaceX's record suddenly looks awful lot better.
                  If we do, NASA's record looks worse.

                  That is one of the problems when you have very little data - tweaking definitions ever so slightly to exclude or include one event can make a massive difference to your "safety record".

                • (Score: 2) by dry on Monday January 15 2018, @08:10PM

                  by dry (223) on Monday January 15 2018, @08:10PM (#622698) Journal

                  It showed a lot of design problems that would have in all probability led to flight failures. In some ways it was lucky that it failed when it did as it forced the engineers to consider things like is it smart to use a 100% oxygen environment combined with lots of flammable materials as well as simple design decisions such as how the door opens.

    • (Score: 5, Informative) by maxwell demon on Sunday January 14 2018, @08:52PM (4 children)

      by maxwell demon (1608) on Sunday January 14 2018, @08:52PM (#622268) Journal

      With 2 fatal failures in 135 missions, the Space Shuttle didn't even come close to those figures.

      --
      The Tao of math: The numbers you can count are not the real numbers.
      • (Score: 2) by frojack on Monday January 15 2018, @01:26AM (1 child)

        by frojack (1554) Subscriber Badge on Monday January 15 2018, @01:26AM (#622357) Journal

        You counting deaths or vehicle here?

        --
        No, you are mistaken. I've always had this sig.
        • (Score: 2) by maxwell demon on Monday January 15 2018, @07:11AM

          by maxwell demon (1608) on Monday January 15 2018, @07:11AM (#622483) Journal

          Vehicles. With deaths, it would be an even worse statistics because IIRC both times there were 7 astronauts on board, while there were plenty shuttle missions with less than 7 astronauts.

          --
          The Tao of math: The numbers you can count are not the real numbers.
      • (Score: 2) by JoeMerchant on Monday January 15 2018, @04:44AM (1 child)

        by JoeMerchant (3937) on Monday January 15 2018, @04:44AM (#622428)

        I moved to Houston in 2003, the tasteless joke of the day was: What does NASA stand for? Need Another Seven Astronauts.

        14 deaths in 135 missions is not a great track record. I'd much rather see a heterogeneous program flying multiple designs and continually refining for improvement, instead of fixing up 20 year old space-pickup-trucks to be used again and again. I drive 20+ year old cars, lots of "interesting" things happen when you try to use a big, complex machine that long, especially when you push the performance envelope with hot turbo pumps & similar things. Interesting in a bad way, if your life depends on it.

        --
        Україна не входить до складу Росії.
        • (Score: 2) by takyon on Monday January 15 2018, @07:04AM

          by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Monday January 15 2018, @07:04AM (#622481) Journal

          We need an alien enemy. Then we can throw military assets in space without worrying about a Cold War on Earth, and it will be totally OK if 1.4-3.3% of the astronauts die, or even ten times that.

          #JWST #SETI #Search4EnemiesToIncinerate

          --
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    • (Score: 2) by beckett on Sunday January 14 2018, @09:36PM

      by beckett (1115) on Sunday January 14 2018, @09:36PM (#622279)

      That's too damned safe. This is a huge part of what makes spaceflight too expensive.

      there is also the matter of high dollar payloads, orbital vehicles, satellites, as well as the significant onboarding cost of training and maintaining human astronauts. being risk adverse with high value assets seems to be a prudent strategy considering the resources for both human and non-human assets.

      some other country - likely China at this point

      If another country takes the risk, then I don't see any problems with this, and you should also embrace their efforts to move the state of the art forward. Or are you still fighting a jingoistic cold war and fighting red commies in your head, an insist on stars and stripes on every launch vehicle? You imply nationalism in your post when you talk about a "pathetic little" country, but otoh your arguments are provincial.

    • (Score: 3, Informative) by JoeMerchant on Monday January 15 2018, @04:36AM

      by JoeMerchant (3937) on Monday January 15 2018, @04:36AM (#622427)

      So, while I generally agree with the water-skiing cliche': if you never wipe out, you're not trying hard enough... on the other hand, you wouldn't catch me boarding any vehicle that puts LOx in contact with composite materials as described in the summary - that's un-necessary risk.

      There's plenty of risks from unknown unknowns in spaceflight, when we get manned missions out of LEO again, we're going to hit plenty of those... no need to add additional risk from known issues that can be addressed in design. Also, a design risk of no more than 1/500 is just asking everybody's best guess to come out to better than 0.2%, not guaranteeing anything about actual risk.

      --
      Україна не входить до складу Росії.
  • (Score: 2, Interesting) by khallow on Sunday January 14 2018, @07:44PM (12 children)

    by khallow (3766) Subscriber Badge on Sunday January 14 2018, @07:44PM (#622248) Journal

    The report raised issues in general about the commercial crew program, including concerns that neither Boeing nor SpaceX, the two companies developing vehicles to transport NASA astronauts to and from the International Space Station, will meet a requirement of no greater than a 1-in-270 "loss of crew" (LOC) risk of an accident that causes death or serious injury to a crewmember. That includes, the report stated, a risk of no more than 1 in 500 for launch and reentry.

    And of course, there is no consideration of the Space Launch System in this. It is likely to have a higher risk of loss of crew due to its extremely low launch frequency. Blowing off the risks of the politically protected, in-house solution is typical NASA behavior.

    • (Score: 1, Troll) by aristarchus on Sunday January 14 2018, @07:57PM (11 children)

      by aristarchus (2645) on Sunday January 14 2018, @07:57PM (#622252) Journal

      I swear, khallow, if you do not stop bashing NASA, there is a greater than 1 in 270 chance that you will be downloaded into oblivious rebuttal-dom.

      --
      #Freearistarchus, again!!!!!1!!
      • (Score: 2, Troll) by khallow on Sunday January 14 2018, @08:51PM (3 children)

        by khallow (3766) Subscriber Badge on Sunday January 14 2018, @08:51PM (#622267) Journal
        I don't buy that you care, but if you do, feel free to give it your best shot. I'll note that NASA played this game with both the Space Shuttle and Constellation programs over the decades. The latter was particularly egregious since they started with a consideration of various competing launch platforms and systematically ignored [selenianboondocks.com] the risks of the favored approach (using a Shuttle-based stack) while specifying that competing approaches had to meet a very high standard. They then hid all those games in an appendix which wasn't released publicly for several years due to alleged NDA restrictions.

        For example:

        Probably the most egregious of the flaws I saw was the exception given in the “ground rules and assumptions” to the Stick concepts. Now, as I’ve discussed before on this blog, tweaking assumptions to make sure that “the right answer” looks favorable is standard fare for trade studies. Now, this isn’t always a case of deliberate larceny. Many times honest engineers can have an opinion about the best route, and when the numbers don’t come out quite they way they expected, they go back and try and see if they “made a mistake” in their assumptions. That said, typically when a honest person is unintentionally massaging the assumptions–or when a dishonest but competent person is intentionally gaming the assumptions–they aren’t as blatant as this (found on page 28, my emphasis added):

        Max dynamic pressure = 800 psf (undispersed), except for certain In-line Crew (ILC) configuration-Solid Rocket Motor (SRM)-In-line cases where the limit was raised to 1,000 psf due to very high accelerations early in the ascent profile.

        Max dynamic pressure = 1000 psf (dispersed), except for certain ILC-SRM-In-line cases where the limit was raised to 1,200 psf due to very high accelerations early in the ascent profile.

        Dynamic pressure (or “q”) is the component of total pressure due to fluid kinetic energy, ie in this case it is pressure felt by trying to shove a high speed rocket through the air. Dynamic pressure is proportional to the air density and the square of the vehicle’s velocity. The maximum dynamic pressure (“max-q”) is an important factor for designing manned launch vehicles, and there are legitimate safety reasons for wanting to keep max-q within reasonable levels. Higher max-q can rapidly drive up the required thrust of an LAS, it drives up the structural stress, especially bending loads, and in the case of a controls problem could lead to tumbling and rapid failure of the stack.

        So, what is it about an SRM-based vehicle that makes it safer to fly at higher max-q? Why do they get an exception, when no other approaches do? To me, the fact that an exception was given only to “ILC-SRM In-line” (aka variants on der Griffenshaft) is what really marks this as an amateur job of assumptions gaming. A clever assumptions gamer would’ve just upped the max-q value for everyone. After all, even though no other alternatives come anywhere close to needing an exception, at least by giving some technobabble excuse like “on further analysis we found that the original GR&A numbers were too conservative” it looks like you’re being honest.

        So now we see the same game being played with commercial launch vendors. It's worth noting here that there probably won't be enough launches of the SLS (assuming it launches at all) to get an estimate of the LOC (loss of crew) within an order of magnitude of 1 in 500. In other words, the precision of the estimate of LOC will be plus or minus 2% due to the low launch frequency of the family of vehicles. But this game will be played right up to the moment when they actually do lose a crew.

        • (Score: 3, Touché) by mhajicek on Sunday January 14 2018, @09:18PM (2 children)

          by mhajicek (51) on Sunday January 14 2018, @09:18PM (#622271)

          I predict that the SLS will have a total loss of crew rate of 0% or 100%. If it fails, it's most likely to fail on the first launch and then never be used again. The other two launches before EOL of the program are far less likely to fail.

          --
          The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
          • (Score: 1) by khallow on Monday January 15 2018, @12:49AM (1 child)

            by khallow (3766) Subscriber Badge on Monday January 15 2018, @12:49AM (#622338) Journal
            Depends whether the first launch is manned or not. That's still up in the air.
            • (Score: 3, Funny) by mhajicek on Monday January 15 2018, @03:35AM

              by mhajicek (51) on Monday January 15 2018, @03:35AM (#622403)

              Bah dum pish!

              --
              The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
      • (Score: 5, Informative) by takyon on Sunday January 14 2018, @10:46PM (6 children)

        by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Sunday January 14 2018, @10:46PM (#622303) Journal

        Bashing SLS does not necessarily mean bashing NASA. SLS is a wasteful pork rocket designed primarily to appease Congress by spreading money around.

        https://www.nextbigfuture.com/2017/09/spacex-bfr-ready-by-2020-so-kill-space-launch-system-and-save-30-billion.html [nextbigfuture.com]

        Falcon Heavy can launch a similar payload to LEO as SLS Block 1. Maiden launch should be within the next two weeks. Maiden launch of SLS Block 1 has been delayed repeatedly to no earlier than 2019 [soylentnews.org].

        If BFR launches before SLS Block 2, it's going to make SLS look like complete crap. If it somehow launches before SLS Block 1, it will be a total bloodbath. As designed, BFR would lift a more massive payload to LEO than SLS Block 2 or Saturn V, while being cheaper than Falcon 9 in reusable mode. In expendable mode, it could lift almost double what SLS Block 2 will.

        Even the evil United Launch Alliance is jumping on the reusable bandwagon [defensenews.com]. But SLS is a collaboration between Boeing, United Launch Alliance (Lockheed Martin + Boeing), Orbital ATK, and Aerojet Rocketdyne that is stuck in the past.

        --
        [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
        • (Score: 2) by takyon on Monday January 15 2018, @01:25AM (2 children)

          by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Monday January 15 2018, @01:25AM (#622355) Journal

          I may have given SLS a bit too much credit. Maiden launch date is no earlier than December 15, 2019. So very likely to be delayed into 2020.

          I would still be surprised if BFR flew before SLS Block 1. I think BFR will face its own delays, just as Falcon Heavy did. But if it did manage to do so, that would be a great time to cancel the SLS program.

          --
          [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
          • (Score: 2) by choose another one on Monday January 15 2018, @10:01AM (1 child)

            by choose another one (515) Subscriber Badge on Monday January 15 2018, @10:01AM (#622508)

            I think BFR will face its own delays, just as Falcon Heavy did.

            I am sure it will, but in the end it just might be a better bet than falcon heavy. I think KSP and the magic struts have given a lot of people a very misleading impression of how easy it is to "just" strap a few well tested rockets together and have them stay together (the hard bit) through launch. FH might work, but may face insurmountable problems - and this stuff is too complex to simulate fully, it'll have to launch. This is why Elon is downplaying expectations for FH.

            BFR on the other hand is in many ways a simpler design and may have fewer problems as a result. The new fuel / engine work seems to be on track and much of the rest is "just" scaling up the vehicle. BFRs biggest problem is probably the size and hence the cost, very deep pockets may be needed which might be a problem particularly if Tesla starts to struggle. I would not discount Blue Origin purely for that reason, although they are a long way behind at the moment.

            • (Score: 2) by takyon on Monday January 15 2018, @12:04PM

              by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Monday January 15 2018, @12:04PM (#622536) Journal

              BFR launches are supposed to be cheaper than Falcon 9 launches. That can only be achievable because part of it is designed to be reusable, as opposed to F9 and FH that throw away the second stage.

              --
              [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
        • (Score: 0) by Anonymous Coward on Monday January 15 2018, @01:28AM (1 child)

          by Anonymous Coward on Monday January 15 2018, @01:28AM (#622358)

          Bashing SLS does not necessarily mean bashing NASA. SLS is a wasteful pork rocket designed primarily to appease Congress by spreading money around.

          That sounds vaguely pornographic.

        • (Score: 2) by mhajicek on Monday January 15 2018, @03:38AM

          by mhajicek (51) on Monday January 15 2018, @03:38AM (#622404)

          SLS pork rocket prototype:
          https://www.youtube.com/watch?v=i0zon3xOaI4 [youtube.com]

          --
          The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
  • (Score: 0) by Anonymous Coward on Sunday January 14 2018, @10:01PM

    by Anonymous Coward on Sunday January 14 2018, @10:01PM (#622294)

    It keeps folks busy instead of poking around looking for something else.

  • (Score: 4, Funny) by c0lo on Monday January 15 2018, @12:02AM

    by c0lo (156) on Monday January 15 2018, @12:02AM (#622331) Journal

    Safety panel raises concerns about Falcon 9 pressure vessel

    Suggested solution: replace the safety panel with a photovoltaic one (grin)

    --
    https://www.youtube.com/watch?v=aoFiw2jMy-0
  • (Score: 2) by linkdude64 on Monday January 15 2018, @02:41AM

    by linkdude64 (5482) Subscriber Badge on Monday January 15 2018, @02:41AM (#622376)

    This just in: Expert Genius Scientist Panel states that strapping people onto rockets laden with explosive fuel and shooting them into the atmosphere is dangerous. More news at eleven.

  • (Score: 0) by Anonymous Coward on Monday January 15 2018, @04:09PM

    by Anonymous Coward on Monday January 15 2018, @04:09PM (#622591)

    "NASA concluded that it would be feasible to move the crewed flight forward to EM-1"

    Flying humans on a first flight seems to be ignoring Murphy.
    The safety sim and analysis addresses things from one viewpoint, but as good as it is, it will never get everything.
    A real, honest flight test increases the test coverage far over the analysis.
    Aside from political (budget?) concerns, what is the rush?
    Fortunately, NASA appears to have pushed back on this.

    "The ASAP strongly recommends that NASA be resourced and begin construction of a second MLP as soon as possible"

    EM-1 and EM-2 need different MLP configurations.
    Instead of coordinating a way so that the same MLP can handle this (Perhaps with extra arms), they want a second MLP.
    This seems poor systems planning resulting in excellent funding for the folks at KSC.
    For somebody trying to accomplish something, seems like a misuse of funds.

    "Additionally, if the alternative (helium) tanks are only flown for
    NASA missions, the potential hazards and impacts arising from operating a unique F9 vehicle at a relatively
    low flight rate (as compared to SpaceX launches for other customers) would need to be carefully assessed."

    Space-X should not let NASA do this. Cheap access to space requires that things work in excess of NASA historical odds for crew safety.
    If the new tank is necessary for this, then it should be used universally.
    If not, then it should not because doing so makes the crewed flight 'special' which means less tested.
    We don't want NASA to make Space-X become the current NASA.

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