46 thoughts on “Xenon”

  1. Great, so instead of using chemical propulsion and investing in cheaper space launch, we’re going to invest in a massive expansion of world xenon production. Because xenon is so much more important than cheap lift.

    1. Uh, no. You place an order for xenon, ten tons, fifty tons, whatever, and you get it 36 month later worst case.

      When Mike Griffin made the statement that there was not enough Xenon in the world to support solar electric propulsion, I was in discussions with Air Liquide about procuring 40 tons per year. With a 40 month lead time, no problem for the first batch and then it is simply a matter of ordering it. At that time Air Liquide had 25,000 kilos sitting in a tank outside of Paris.

      1. OK, but then you’re still investing in very high-power SEP, when cheap lift is much more important.

        1. That faith based belief in CATS is what has held spaceflight back for decades. Demand generates technology advancement.

          If large aerospace firms see an actual demand for CATS, versus the hand waving of space advocates, it would be here. That is the lesson of DC-X. The failure of DC-X wasn’t technical, it was because no one could build a credible business model to justify commercial investment.

          1. That’s exactly my point: if NASA does this with abundant chemical propellant and procures launch services for it competitively and redundantly, then there would be a massive market.

            No NASA propellant market: no business case.
            NASA propellant market: business case.

            Therefore: NASA has the opportunity to make CATS happen. But they selfishly choose Orion / SLS. SEP by itself is very useful, and we could build 50-100kw propellant tugs with off the shelf technology. No complaints there. But there is no need to invest in high power SEP just yet, let the market take care of that.

          2. Martijn,

            The one problem with government markets, even for fuel, is that often disappear with a change of the political winds. The home Solar industry was mostly wiped out that way in the mid-1980’s.

            You need real honest commercial markets, not government ones, to build a solid industry.

          3. That faith based belief in CATS is what has held spaceflight back for decades.

            Yes, Tom. It’s not as if anyone poured hundreds of billions of dollars into a Moon Rush, as you an Dennis advocate. Oh, wait…

            Demand generates technology advancement. If large aerospace firms see an actual demand for CATS, versus the hand waving of space advocates, it would be here.

            Yes, of course. If zeppelin companies saw an actual demand for airplanes, versus the handwaving of aviation advocates, they would be there. If mainframe companies saw an actual demand for microcomputers, versus the handwaving of Steve Jobs, they would be there.

            Typical worthless MBA advice.

          4. Say’s Law of Markets [Econ 101]: “Supply creates it own demand.”

            Silicon Valley has gotten rich creating products for which there was no previous market. Microcomputers, iPhones, web browsers, search engines….

            Of course, if Tom’s argument made any sense, it would apply to the Xenon rocket also: If there was any use for Xenon propulsion, someone would have built it already…

            Back in the 1990’s, we heard the same thing, from the same people — except then, it was ISS that was going to be our salvation.

            All we needed was for NASA to spend $100 billion building it, then companies like SkyCorp and Orbital Properties would rush in to commercialize the station. SkyCorp alone would generate enough revenue to pay the station’s entire annual operating cost. ISS would quickly evolve into Alpha Town.

            Hard-headed engineers like G. Harry Stine, who did the math, were ridiculed (and still are). Zealots said launch costs would take care of themselves, once there was a destination.

            It’s 2013, and there is no Alpha Town. No one is promising to pay the full operating costs of ISS out of annual revenues. The companies using ISS are asking the government for free rides, because in the real world, launch costs do matter.

            But now we’re told the answer is building ISS2 on the Moon. Or maybe L2 or Mars… pick your favorite destination.

            The validity of a science is its ability to predict. Stine, et. al. correctly predicted that attempts to commercialize space would fail until costs were reduced. But people continue to ignore the flaming datum.

          5. So, how long will be it be before Tom denies that he wrote this and once again claims he’s “always been” a supporter of CATS and suborbital science?

            Two weeks? One week? 24 hours? Anyone care to start a betting pool? 🙂

        2. Cheap lift will take care of itself. Once there is human access and more humans in space, along with more commercial destinations, cargo will be the driver. Competition will drive cheap lift and innovations will be the natural state, the exact opposite of biggov/nasa.

          Just look at the upgrades in engines by SpaceX in a decade… once commercial destinations are in place innovations will be occuring a lot more frequently. IMO

          1. Exactly, Europeans didn’t start improving sailing ships until they found there was big profits to be made from trading along the African coast. Then improvements came rapidly, followed by more when they found the New World.

            Same with aviation. Advances lagged until World War I, then shot ahead.

            So there are really two ways to achieve CATS. One it to find some good markets in space, the other is to have a nice war there. But I suspect most would see the first as the better option 🙂

          2. I’m afraid there will be no commercial cargo to let this take care of itself. An asteroid mission could be used to create that cargo, in the form of chemical propellant that’s needed for that mission. If you use SLS (and use SEP to make it possible to do that with a small number of SLS launches), then you get *no* additional commercial cargo.

          3. Same with aviation. Advances lagged until World War I, then shot ahead.

            Maybe in Bizarro World.

            In the real world, there were 2,000 certified pilots and over 10,000 pilots by 1912 — in France alone. The European aircraft industry was turning out more than 500 planes and generating $45 million per year (over one billion US dollars).

            All of this happened *prior to* World War I, the Air Mail Act, and the development of commercial airlines. It was primarily the result of sport aviation.

            In the United States, Bill Boeing founded a small aircraft shop to endulge his interest in sport flying. He planned to build one airplane, for himself. That was before the US entry into WW I. At last report, the Boeing Co. is still active in the airplane business.

            Was there an angry, bitter community-college professor telling everyone they shouldn’t build airplanes until hundreds of billions had been invested in international airplanes, computerized air-traffic control systems, and new destinations like Las Vegas? If so, no one would have listened. Neither should we.

        3. OK, but then you’re still investing in very high-power SEP, when cheap lift is much more important.

          Answer this question. What is more costly, a kg to LEO or a kg to the Moon? If you are lofting payloads from LEO to orbits above, you are lifting over 4X the payload weight in fuel. If you are using a SEP, that fraction drops to 1.75-2x.

          1. Of course, but the crucial question is what does it cost to launch a kg to LEO. As long as that doesn’t get down to $1000/kg or less, commercial spaceflight isn’t going anywhere. There is no prize for minimising IMLEO, there is a prize for reducing launch prices.

            An exploration program that uses a lot of chemical propellant launched on freely competing commercial launchers has the potential to drive commercial launch prices down by an order of magnitude. One that uses SEP to make a particular mission fit on a single HLV launch doesn’t.

          2. An exploration program that uses a lot of chemical propellant launched on freely competing commercial launchers has the potential to drive commercial launch prices down by an order of magnitude. One that uses SEP to make a particular mission fit on a single HLV launch doesn’t.

            I don’t give a hoot or holler about HLV but SEP makes a lot of sense until we get lunar propellant production going. We will agree do disagree.

          3. Answer this question. What is more costly, a kg to LEO or a kg to the Moon?

            Your arch-enemy Zubrin would say c) Mars, but the correct answer is c) a kilogram to Alpha Centauri!

            You are falling into the same trap as Kennedy, who famously “chose to go to the Moon” because “no other goal will be more expensive to accomplish.”

            If you follow that argument to its logical conclusion, you’ll never start anything. You can always find a more expensive destination, Dennis.

            The fact that LEO is less expensive than the Moon (and suborbital is expensive still) is not an argument against it. It’s an argument for it.

            We have to crawl befor we walk and walk before we enter Olympic Decathalons. We know how to go the Moon, at any cost. We did that in the 1960’s. The goal now is to go there affordably. Which means developing the means to get off the planet affordably.

  2. World production of Xe is about 1 ton per year because that’s what the world uses. It’s a simple and cheap (relatively) matter to increase that amount by a factor of at least 20.

  3. And to think that is is coming from the same people who say we need an HLV. First build an HLV you can’t afford and then invest in minimising the only affordable payload you have for it (propellant).

  4. Producing Xenon is easy; it’s most often obtained by refining liquified air into oxygen and nitrogen, and then further distillation. So unlike some things, the raw material isn’t scarce. What this does mean, though, is that production capacities have to be taken into account (Such as the cost of expanding them) which apparently they aren’t.

    That does not surprise me, for I consider this whole mission a fiasco. I think it’s preposterous, because it would be both easier and cheaper, along with vastly more useful, to retrieve large samples via unmanned missions and bring them to Earth than to move a very small rock (a rock smaller than the spacecraft that’d be sent out to it) to lunar (or a Lagrange) orbit and do a manned mission to study and sample it there. It simply makes no sense.

    1. Even the cost of expanding capacity for Xe is not high compared to the proposed cost of the NASA asteroid mission. I’ve seen a firm fix priced quote for an amount of Xe greater than that required for the asteroid mission. The only thing to worry about with regard to Xe is lead time. While expanding capacity is easy and relatively cheap it does take time. There are lots of things to worry about with the proposed asteroid mission but Xe isn’t one of them.

  5. With a 40 month lead time the Xenon providers can ramp up to whatever level is needed. Xenon is a byproduct of liquid oxygen production.

    This is a damn Mike Griffin style strawman.

  8. Two of my friends back in college (both physics majors) had an incident with xenon. One, noting that helium raises the pitch of your voice, reasoned that breathing xenon should drastically lower the pitch of your voice. So he took a big hit of xenon, and sure enough, he became super bass.

    Then he started turning kind of blue, because xenon is much heavier than air and settles in the lungs. The other friend, reasoning that out, grabbed the guy by the legs and flipped him upside down so the xenon would drain out, which it did.

    2. Your friend was lucky. As it happens, xenon is a rather effective anaesthetic. It’s not used more than it is because of the cost.

      I’m told that trick works well with other heavy, unreactive gases but the same problem is potentially there. The best would probably be SF6.

    3. I was told the story that in making the film “Blue Velvet”, David Lynch had the creepy-pervert-sadist character taking hits from a “tank of helium.”

      The story goes that actor Dennis Hopper, who was cast as the creepy-pervert-sadist, and perhaps had the chops to offer technical script advice on drug culture and on creepy people, made the suggestion to Lynch that the character could be inhaling from a tank of nitrous oxide.

      To which David Lynch replied, “What’s that?”

  10. Erik, yea this crazy canard is brought out every now and again. Mike Griffin used the excuse that there was not enough xenon in the world as his reason to dismiss Xenon ion propulsion as part of Constellation. There is 400,000,000 tons of it in the atmosphere. There is twenty times more Krypton in the atmosphere and it only reduces ion thruster performance about 5%.

    I am simply amazed that any competent engineer would make such a statement. Who the hell said this at AIAA?

    1. I think MfK won the Internets with his above observation that the people afraid of xenon are xenophobes.

  11. I don’t give a hoot or holler about HLV but SEP makes a lot of sense until we get lunar propellant production going. We will agree do disagree.

    I actually agree that SEP is very useful. Fortunately there is off the shelf technology we could use. 50kW-100kW can be done with existing technology. I don’t agree now is the time to invest in multi-MW SEP because cheap lift is far more important. That will only become useful to commercial space once we have cheap lift.

    Now if you used just 50kW SEP tugs to haul storable propellant from LEO to L1/L2 in support of an asteroid mission, that would be great. You can do that with off the shelf technology and mostly off the shelf systems. And the nice thing is, if you simply procure the propellant at L1/L2, then you can let the market decide how to get it there.

    It can also decide how much money to invest in R&D, and how to allocate that money to different kinds of launch technologies (VTVL RLVs, mass-produced expendables, air-breathers, …) and in-space transportation infrastructure (SEP, cryogenic depots, tether, …).

    That way you get rational decisions and real results instead of first thinking of something expensive for JSC to do and then rationalising it. The monster SEP tug and L1/L2 gateway station are old standbys that are trotted out everytime the current plan threatens to fall apart.

    1. Martin

      We are in agreement, though our modular system can easily scale to half a megawatt without undue expense.

      1. I actually wondered what the limiting factor was. I had a look at Alphasat and to my interested layman’s eyes it isn’t clear why you could not easily double or triple the power simply by adding more panels. There appears to be enough space for it and mass can’t be a problem either. I’m guessing it has to do with solar panels not getting in the way of transponders.

        1. Power distribution is the biggest problem. We solved that by going modular with modular propulsion units so there is no limit really. In practice it is probably about a megawatt.

    2. Where did you get multi MW SEP? From page 6 of the Keck Report: “The transportation capability would be enabled by a ~40-kW solar electric propulsion system…”.
      I would love to see a 40-kW SEP. Such a vehicle could be a game changer for lunar development as well as asteroid use. The much maligned Asteroid Redirect Mission would develop some enabling technology.

      1. Agreed, such a tug would be great. I don’t think it is optimal to invest in it now, but if that’s the price to be paid for creating an orbital propellant market, fine. But the current plan is to use it to prevent the need for multiple launches to perpetuate the myth of the need for an HLV. In a sense you could say that the tug is being used to prevent an orbital propellant market.

  12. You can also extract xenon and krypton from the air at room temperatures and pressures using metal-organic frameworks and pressure-swing adsorption.

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