The Diane Rehm Space Discussion

Marcia Smith has a good summary. This amused me:

Rehm exclaimed that she didn’t understand what Gold meant because the “language you’re using” sounds “proprietary” and one cannot own the Moon. Gold began answering, but apparently the show ran out of time for that segment (music began playing) and he was not able to fully respond. Rehm said it “sounds confusing to me,” and cut him off.

Diane Rehm always strikes me as someone who is easily confused. I’ve never understood her popularity, except that a lot of Beltway denizens share her propensity for confusion.

[Update a while later]

Monumental willful ignorance from Mark Whittington:

The cancellation of the SLS, unlikely in the current political climate, would mean the end of any hope of sending American astronauts beyond low Earth orbit for the foreseeable future.

If you can’t see beyond the next five years, perhaps. It’s the lack of propellant storage and transfer technologies, and landers, that is keeping bound to LEO, not lack of heavy life. Money wasted on SLS is trapping us there.

Expect him to show up shortly with his standard, foolish, “But you provide no alternative,” despite the fact that he’s been shown alternatives many times. We can explain it to you, Mark, but we can’t understand it for you.

50 thoughts on “The Diane Rehm Space Discussion”

  1. Actually the NASA internal study convinced me that fuel depots with current launchers would be a non starter. Six launches each for a moon mission. Nine launches each for an asteroid mission. No missions to Mars. Oh, and only four beyond LEO missions in a decade if everything works right (which it won’t.) In contrast, even post Apollo 13, we were doing two moon landings a year in the early 1970s.

    Mind, fuel depots supplied by lunar resources and heavy lift would be great and would make beyond LEO operations a lot easier in the long run. But there is no getting around the necessity for the big rocket. Anyone who says otherwise is either delusional or is trying to sell something.

    1. IF (and that is a huge if) a “big rocket” is needed it is best supplied by SpaceX in the form of Falcon Heavy, Falcon X Heavy or Falcon XX etc. Any of which could be developed and flown for a fraction of the money being heaped upon the SLS alter.

      SLS exists for one purpose: keeping shuttle money flow to key congressional districts.

    2. “Six launches each for a moon mission. Nine launches each for an asteroid mission. ”

      Why does the number of launches matter, aren’t the important factors cost and time?

      “Oh, and only four beyond LEO missions in a decade if everything works right (which it won’t.)”

      Isn’t that more than planned SLS missions?

      “Mind, fuel depots supplied by lunar resources and heavy lift would be great and would make beyond LEO operations a lot easier in the long run.”

      This is space where the simplest things take a decade and a misstep can cost a decade or more. When dealing with decades, we are dealing with significant portions of a human lifespan. We really need a strategy that operates in the long run.

    3. Six launches each for a moon mission. Nine launches each for an asteroid mission.

      There were eight Atlas 5 and three Delta IV flights in 2013, so doubling those numbers would give you 2 moon missions a year. No doubt at less cost the SLS, and as pointed out, getting SpaceX to do it would make the missions less expensive, maybe even affordable.

      1. Also, each EELV was designed for 20-40 flights a year. A large part of the reason they are so expensive right now is that they get nowhere near that rate. Consolidation has reduced total capacity, but together they should be able to reach 20-40 flights without enormous new investments.

    4. One of the flaws of the SLS design is that it isn’t really scalable. It can’t be made bigger than the Block IIB because it would scrape the ceiling of the VAB, and it doesn’t downscale because it can’t be launched without the strap-on boosters. Like the Saturn V and the Shuttle, the mass it launches into orbit is what it is, leaving it with a narrow niche of payloads that happen to match.

      In contrast, the Russian Angara, Chinese Long March 5, and several other systems can be launched with a widely varying number of strap-ons, allowing them to cover a much broader range of payloads. A more versatile big booster would perhaps be configured so it launches 150 tonnes with four strap-ons, 100 tons with two, or 50 with none, or some such.

    5. Mars missions weren’t part of the study, because they’re not on the planning horizon of NASA using any architecture. Fuel depots are fantastic because they have a lot better tolerance for failure and for incremental design changes than using big launchers. Fuel depots are also better able to take advantage of improvements in the launch market. There’s a high likelihood that a fully reusable propellant transfer vehicle could be developed in the next several years, if propellant depots are developed. And that would make it possible to deliver propellant to LEO for around $1 mil/tonne, which would make it possible to put cargo on Mars for perhaps $5 mil/tonne or so. At that point it’s just a matter of ongoing investment in order to build up a Mars colony.

    6. Actually the NASA internal study convinced me that fuel depots with current launchers would be a non starter. Six launches each for a moon mission. Nine launches each for an asteroid mission.

      That’s a hard complaint to take seriously. A large number of launches doesn’t indicate impossibility since just about everyone who launches stuff to orbit has done so more than once, often dozens or hundreds of times. It might require a faster launch tempo or more significant launch logistics and infrastructure, but I’m not seeing what’s supposed to be the problem here.

      And once again, you’re comparing the performance of real world vehicles that fly now versus a paper rocket that probably will never fly.

      In contrast, even post Apollo 13, we were doing two moon landings a year in the early 1970s.

      I don’t get what’s supposed to be impossible about twelve or so launches a year (which would be the equivalent, according to your study). We could afford that many launches now on what we blow on SLS development (Atlas V and Falcon 9, for example).

      But there is no getting around the necessity for the big rocket. Anyone who says otherwise is either delusional or is trying to sell something.

      The thing is we might have to get around that “necessity” simply because no one, including NASA, actually builds that big rocket.

      I think the lesson here is that one shouldn’t make hard problems harder by putting large obstacles in the path. This has repeatedly been done with space exploration beyond LEO with the “big rocket” being put in on the critical development path and never actually being developed. In that case, no rocket means no beyond LEO space exploration.

    7. Actually the NASA internal study convinced me that fuel depots with current launchers would be a non starter.

      Except that you had been saying this for years when the study came out. Are you a time traveller? If so, just go back to the sixties. See if you can stop Kennedy from getting assassinated, I’d like to know what would have happened.

    8. Just so we have a benchmark, NASA has scheduled 13 launches to support ISS for 2014, 4 from SpaceX alone. I think that pretty much makes the whole “X Number of launches!!!” nonsense moot.

      1. A single Trident submarine can launch 24 missiles in just a matter of minutes. I guess Mark forgot to tell the Navy that multiple rocket launches are impossible.

        And the Air Force. And the Army. Not to mention a bunch of foreign militaries. Even the Nazis managed to launch over 3000 V-2 rockets, in less than a year, while the Allies were bombing them night and day.

        1. “A single Trident submarine can launch 24 missiles in just a matter of minutes. ”

          has that ever been demonstrated?

          Of course, i don’t think you are really suggesting we try and make orbit with big solid multi-stage boosters?

        2. To be fair you have to consider the rate at which the rockets can be prepared for launch, including necessary manufacturing for expended components. But the rate at which we could prepare rockets for launch appears to grossly exceed the rate at which we launch them.

    9. Six launches each for a moon mission, lets see here … six Falcon 9 launches 55 million each 330 million. One launch of the SLS 2.5 BILLION…

      Gosh Mark .. thanks for proving the opposite.

      what a nutcase.

    10. NASA is spending so much money on the SLS and Orion that it has nothing left to develop other essential payloads like lunar landers and transfer stages. The SLS is a big honking rocket to nowhere. It amazes me that you can’t grasp that basic fiscal reality. To paraphrase the song “Old Time Religion”,

      “Give me a big honking rocket
      Give me a big honking rocket
      Give me a big honking rocket
      It’s good enough for me.

      It was good enough for Apollo
      It was good enough for Apollo
      It was good enough for Apollo
      And it’s good enough for me.”

      Never mind that Apollo turned out to be an unaffordable dead end.

    11. “In contrast, even post Apollo 13, we were doing two moon landings a year in the early 1970s. ”

      Apples/Oranges. Apollo got a lot more money, and if a commercial/depot based exploration path received similar amounts, it would outperform the projections based upon more limited amounts of money, and outperform Apollo. Budget = mission rate.

      If you read that study, you would know that the commercial launch/fuel depot approach outperformed the SLS based one on a more realistic budget envelope. After all, SLS is not doing two moon landings a year either. Try none.

      Furthermore, future competitive evolution of the commercial launch industry can enable more missions for the same budgets. So even the projected mission rate can be conservative. A throwaway billion dollar booster based exploration model is going to look even more anachronistic when the industry moves on to partially reusable and fully reusable vehicles.

      I don’t think you grok how the commercial launch industry works. Launch rate is expandable based upon orders. You order more launches, pay the ticket price, and they’ll be launched, no matter if you ordered 6 or 20. You’re bound to see impressive launch numbers by the domestic commercial launch industry in years ahead, that will put SLS to shame.

  2. “The cancellation of the SLS, unlikely in the current political climate,”


    “would mean the end of any hope of sending American astronauts beyond low Earth orbit for the foreseeable future.”

    True, not because there are not other options besides SLS but because these other options are not far enough along to be relied on for making predictions with a date attached. It is less a question of capability than it is of the strategy chosen by our politicians. False, because everything hinges on the word foreseeable and SLS missions take place beyond what is foreseeable, especially when considering political cycles.

    “With the SLS, which is actually proceeding on time and on budget, there is at least a chance of that happening.”

    I am skeptical. For me the issue is time and what we can do right now as opposed to waiting for SLS to be developed, then for payloads to be developed. The money spent on SLS could buy a lot of payloads and launches on commercial launchers. SHLVs have merit but I don’t think it should be NASA’s role to reinvent the wheel. COTS and CCDEV have shown a better way.

    1. The problem is that there are no commercial launchers that have the capability that the SLS will give us. Cancelling the big rocket would mean the end of hopes for American beyond LEO space exploration for a generation (again!)

      1. Wrong again Mark.

        The Block I SLS will have a LEO payload capacity of no more than 70 tons and won’t fly before 2017, if then.

        Falcon Heavy will fly within 12-18 months and will have a LEO payload capacity of 60 tons.

        The 130 ton capable SLS will not fly before 2030, if then. Smart money says that SpaceX can have a Falcon Heavy XX with that lift capacity well before 2030.

        Your notion that the only way beyond LEO is with a 20-40 billion dollar white elephant launcher is ludicrous.

      2. If we’re really going to get serious about interplanetary flight, we need to develop nuclear engines.

        Launch the components with multiple smaller boosters, assemble them in orbit, and off we go. This has been known since the 1950s.

  3. When I first moved to the Baltimore Washington area, I listened to NPR almost exclusively because it was the only thing that came through clearly in the area’s hideous RF environment (AM is impossible). I listened with incredulity to Diane Rehm for a bit, thinking that perhaps there was a gag going that I’d someday get — sort of like listening to Phil Hendrie when he first appeared on KFI. I thought perhaps that this was Emily Litella on steroids.

    Alas, this doddering, senile, 77 year old biddy is just that. I wish it was a put-on. Instead, it seems like a cruel joke on an old lady…

    1. She is kind of a hoot and from the parts of the broadcast that I caught, clearly out of her depth,

      1. If anyone is out of their depth on space issues it would be you Mark. You have been wrong about everything so far this century.

  4. Whenever I hear Rehm’s voice, I have to reach for the “off” button on the radio before I scream. Her voice is like nails on a chalkboard.

    I suspect it _might_ become tolerable after a few months if she’d drink more liquor and smoked …but not placing any bets on that.

  5. Has anyone figured out how to get past the blog weirdness where apparently old versions of the comments are displayed? It’s not a cache issue on my side since I’ve seen it for articles I’ve read for the first time (and have no opportunity to create a cache). I see on the main page that there are supposed to 15 replies to this article, but here I only see 13 replies. This is particularly unfortunate since I think, but am not sure that I posted here. I don’t want to post the same thing again.

    In the past, these pages have updated when I post, so well, I’ll probably find out for sure once I’ve posted this.

    1. There are some interesting quirks on this website. Sometimes, the front page will say there are multiple comments for an article but when you open it, none are there. Reloading the page sometimes helps bring up any additional comments since the last time you looked. Closing the browser completely (at least with IE) and then reopening the page seems to help.

      1. A couple days ago I left what appeared to be the first comment on a thread, but when I looked at it again later there was another comment before mine that wasn’t there the first time I looked.

    2. My suspicion is that some routine was added that’s walking on a variable that keeps track of the number of comments, or some such thing. It is a bit of a nuisance.

  6. I’ve yet to hear how payloads for the BFR are going to be paid for. I’ll grant that SLS is technically possible, from what I can tell. It will quite probably eventually fly, if not cancelled first. But what’s the point of a rocket that is so expensive you can’t afford to build payloads for it?

    My hat’s off to the engineers who are working on SLS–they’re surely doing the best they can with the cards they’ve been dealt. But in the current budget climate, it’s very hard for me to see SLS as a viable program long-term. And the NASA budget is very unlikely to grow significantly, IMHO.

  7. It’s the lack of propellant storage and transfer technologies, and landers

    No, just the landers, existing propellant storage and transfer technologies would have been enough, just as they have been for the past thirty years. Insisting on cryogenic depots in LEO is almost as senseless as insisting on HLVs first. Sure they make certain things easier, but they’re not necessary. It’s the desire to protect Shuttle / Constellation / SLS + Orion that has kept NASA from going beyond LEO and meaningful numbers of private citizens from going into LEO.

    We need a large and fiercely competitive propellant launch market in order to stimulate private development of (initially small) RLVs, and we can do that with 30 year old technology. If NASA had chosen, and been allowed to choose, a wiser course when Obama took over, we could have had such a market right now.

    1. One of the common errors used to slap down propellant depots and say the basic technology isn’t there is the assumption that boiloff rates must be exceedingly low. As a ULA engineer pointed out to me several years ago, once you relieve that just a bit, except for a few tech refinements and proofs we’re just fine.

      Moreover, if you have the market for _using_ large amounts of fuel from depots, you surely have the ability to supply the depots with a small fraction extra for boiloff.

      1. I’m not making such an argument. I’m just arguing for incrementality and for letting marketing forces decide on investment. Hypergolic in-flight refueling of a spacecraft at a Lagrange point is enough to get started with both exploration and that propellant market. Once the demand is in place, all the pieces of a transport infrastructure (RLVs, depots, tugs, SEP etc) will fall into place as traffic warrants. And once we have the RLVs, there will be no turning back. Let’s not add unnecessary risk, cost or delay on the road to that point, it’s far too important for that.

        I’m sure early LEO depots will become viable even with just 30 days of storage without excessive losses. ZBO is a long term goal, not a short term necessity. As are cryo depots themselves. It’s the propellant flights and the RLVs that matter, not the depots.

      2. The market might be happier with storable fuels for depots, which avoids most of the problems and could provide the kind of fuels for the satellites that don’t use cryogenic propellants, which is all of them.

        We could also move toward higher performance storables. Even avoiding beryllium , fluorine, and lithium, there are ones such as hydrazine/pentaborane, which has a very wide temperature range and gives an ISP of around 400.

      3. Boiloff is really only a serious problem if you insist on using LH2. As I pointed out in another reply it’s easy to maintain sub LN2 temperatures in LEO, as demonstrated by the WISE mission in its refrigerant depleted warm phase. Which means that all you need to keep boiloff rates exceedingly low for LOX/Kerosene or LOX/Methane is some multi-layer insulation and maybe a sunshade. If you want to gild the lilly with LOX/LCH4 you can have a coolant loop of LN2 and a cryocooler, both of which are pretty dead simple technologies these days.

        1. I have no strong opinions either way about use of hypergolics in the long term. It would be nice if they were replaced with something less toxic and with higher Isp. For some applications, that will be SEP. For higher thrust applications, who knows.

          The reason I do care strongly about using hypergolics in the short term is because we’re in a hurry. None of us are getting any younger, and I’d like to see space opened up before I die. At any time in the past thirty years we could have built a refuelable hypergolic spacecraft and used it to explore and to create a arge and fiercely competitive propellant launch market. Had we done so, we could have had a thriving commercial manned spaceflight industry by now, complete with orbital hotels, lunar casinos and Planetary Society expeditions to Mars.

          The point isnt’t that hypergolics are perfect (though they are pretty darn good for spacecraft, which is why everybody is using them), the point is that they are good enough and we’re in a hurry. As soon as we break the magical $1000/kg barrier, things will take off and all systems will gradually be replaced by more advanced ones.

          In the long run, this argument will become moot, because if we wait long enough, someone will figure out how to do cryo depots. It would be better if we didn’t have to wait that long.

          And if you’re waiting for cryo depots, why not wait for the next thing? Maybe NTR, maybe ISRU, maybe aerobraking, or variable mixture ratio thrusters etc etc. Whatever you use, there’s always a next step. In light of that, and the fact that we have 30 year old technology we’re not even close to using to its full potential, it seems to me the only non-arbitrary choice is to go right now, with what’s available *right now*.

        2. Robin,
          SMD and the military has made liquid helium (4 K and below, along with only slightly better heat of vaporization than LH2) and even solid hydrogen last a really long time (up to 5 years for a 1000 liter tank) in LEO on many, many times. Now certainly there are issues with scaling from these smaller tanks to tanks on the scale of say a Centaur – but NASA has been proposing a demonstration (i.e. saying the technology is ready to fly) since the early 70s (see Mars Nuclear Rocket and Project Thermo).
          Recently, after several false starts (Project Thermo, ColdSat, Cryogenic Fluid Management Experiment), NASA has funded the Cryogenic Propellant Storage and Transfer Technology Demonstration Mission to do exactly that, demonstrate long duration hydrogen storage.
          Also, by the way, the project demonstrated exactly what you propose for LOX: cooling of a tank via a tubing network attached to a cryocooler.

  8. …there is no getting around the necessity for the big rocket.

    Keep your space ship under 13 tons and an F9 can put it in orbit and a refueled F9 upper stage could send it to the moon or mars. One F9H provided refueling. Another F9H prepositions a landing in orbit (both moon or mars)

    One example proves you wrong which I just provided. Other launches can preposition supplies at your destination. The need for big rockets is market driven and will not happen until we develop the markets with smaller launch vehicles.

    Both SLS and Orion are too massive for the current market and too costly being a government program. This is obvious. What’s not obvious is why this dead horse keeps getting beaten.

  9. I think we need to remember that America’s last space station, Skylab, was launched on the Saturn V moon rocket, Skylab weighed around 90 tonnes, obviously with rockets only capable of lifting 25 tonnes, this will be the upper limit for the mass of any future space stations.

    1. Sure. Which means the 450-ton ISS must have been put there by aliens. Assuming you’re being serious – ever hear of in-orbit assembly?

      Incidentally, I admit almost complete ignorance of the question I’m about to discuss. Non-chemical engines (he particular one, IIRC, being a xenon-based ion engine) have been used for unmanned missions. Are there any plans, at all, to use ion or plasma engines with their much higher Isp for manned missions?

      1. That’s the punchline.

        As for electric propulsion this is another example of NASA failing its job. Pulsed plasma thrusters are almost certainly the best option for propulsion of manned interplanetary missions in space. But the technology is horribly underdeveloped. Last year a few engineers put together a kickstarter (raising less than $75k) to fund a basic proof of concept device that was quite successful. That’s the sort of thing that NASA should be doing, and the cost is so crazily low that it’s almost ridiculous they’re not.

        Ion engines are currently the darlings of the powers that be when it comes to electric propulsion but they aren’t actually that good. They are helpful for a certain class of mission, where they can provide a significant advantage, but for manned missions they are almost useless. They have too low thrust levels and too short a level of endurance. PPTs on the other hand are in a much better sweet spot, especially for manned missions. They have enough thrust to send a manned mission on its way to another planet with only a month or a few months of operation, and they have potential longevity which enables >10 km/s accumulated delta V from one device (making them useful for round-trips and extended off-Earth usage).

        1. I heard something a while back about plans to install electric thrusters on the ISS to maintain it orbit, currently it gets the occational boost from Progress.

          To get any benefit from electric thrusters you need a major light weight energy supply, that’s the hard bit. There are various proposals, all a long was from realization.
          Google Mars in 39 Days

          1. The major light weight energy supply is required because the higher exhaust velocities that electric thrusters can give you gobble energy at higher thrust.

        1. That’s why I specified “assuming you are serious.” Sarcasm doesn’t come across all that well on the Internet and I don’t know you at all well. My bad for not spotting it. :$

          Regarding propulsion tech – insert obligatory Orion mention here…

  10. “Pace said the advantage of Constellation was that it started with the smaller Ares I (needed for the Moon), with the larger Ares V (needed for the Mars mission….”

    Spudis has been saying for years that Griffin and his cronies ditched the goals of VSE for their own Mars HLV agenda. Pace’s statement verifies Spudis’ accusation IMO.

    1. I think Pace is just using that as a contrived excuse for the institutional work program he favours, shuttle derived launch vehicle development. He doesn’t really care about those ends, but rather uses it as cheap justification for the SLS; Mars missions are on so far a horizon they don’t really exist. Pace, to me, is clearly a partisan for sdlv based missions to the moon, and hostile to anything else.

      Spudis is in his own lala land obsessing about his own belligerent sdhlv fanaticism and “newspace” hatred, to the point where he has more allegiance to the space shuttle program industry than his own deluded and messianic lunar visions, so they are not that far apart.

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