That Doug Cooke Op-Ed

I just realized that I started this a few weeks ago and never finished it. Not sure I have the gumption to do so now, but I might as well publish what I’ve done.

**************************************************************************************

These SLS apologia are so tiresome. I’ve been too busy to respond to them, but maybe I will fisk this one. My comments in italics:

The release of Space Policy Directive 1 in December 2017 redirected the U.S. civil space program to pursue a sustainable program of exploration with a near-term emphasis of returning humans to the moon. Since then, the related details indicate an aggressive schedule to initiate lunar activities, and a desire for much of the architecture between here and the moon to be reusable. Reusability has been partially implemented before, but recent SpaceX and Blue Origin booster landings have reignited hopes that reusability can change the economics of space activity simply by switching from expendable to reusable launch vehicles.

[Caption: The intertank that will be flown on Exploration Mission-1 as part of NASA’s Space Launch System heavy-lift rocket has completed its avionics functional testing at the Michoud Assembly Center in New Orleans. The avionics, shown here inside the intertank structure, guide the vehicle and direct its power during flight.]

Note that the picture and caption have nothing to do with the point about reusability or expendability. They are simply tech porn for people who get off on giant rockets.

Aggressive schedules and reusability are well understood and directly relate to space exploration. However, sustainability has subtle but important implications in the space exploration domain. Sustainability is the ability to maintain competency levels and the delicate balance for all supporting elements of a program over a long-term program in an affordable manner.

This is certainly not how I would define “sustainability.” I would define it as the ability of a program to be sustained, financially and (in the case of a government program) politically. And we also have different definitions of “affordable.” If you’re of the Apollo mindset, “affordable” means at a low-enough cost, combined with the political benefits of distributing taxpayer funds to the politically important zip codes, that budgets can be maintained year on year, from one Congress and administration to the next. I have a different definition. I view affordability as the ability to financially enable large-scale space activity, both government and private. But large-scale space activity is the opposite of the Apollo mindset, to which too many remain in thrall.

For space exploration, this balance is hard to achieve as these programs are expensive and funding-constrained. Especially in large-scale programs such as those involved in human space exploration, budget constraints can drive short-term decisions that result in atrophy of knowledge and expertise, needed equipment, and processes that are part of the program life cycle, leading to limited or no retained capacity. Such decisions are sometimes unavoidable, but will ultimately undermine programs long-term.

As I’ve noted over the years, there are hidden assumptions in this paragraph. The first is that the purpose of human civil spaceflight is “exploration.” This is a fiction that goes back to Apollo, and it creates a false mindset that allows the kinds of programmatic insanity represented by programs such as SLS/Orion. But in fact, the purpose of human spaceflight in the sixties was to defeat the Soviet Union in a peaceful battle in the Cold War, since then, the purpose has been to maintain the jobs base created by Apollo and supported by those in Congress who (with rare exceptions) insinuate themselves onto the committees in Congress that control space spending in order to steer taxpayer funding to their states and districts. Actual accomplishments in space, let alone in “exploring” it, have always played third or fourth fiddle. SLS/Orion, which have spent billions for many years, with little to show for it, are ideal to meet this need, with no need to actually accomplish anything.

Absent more specifics about what kinds of “short-term decisions” he is describing, I can’t really comment on that. I would note that in fact the entire op-ed is short on specifics, which of course makes it harder to throw rocks at it.

Despite the challenges associated with sustainability, great strides have been made in human spaceflight since the first mission of NASA’s Mercury program in 1961. This November, the U.S. space program will soon achieve a milestone of 18 years of continuous human presence in space on the International Space Station (ISS). That accomplishment has been built from the lessons learned through NASA’s Gemini, Apollo, space shuttle and ISS programs, but there is still need for improvement. As the U.S. space program now looks to the challenges of long-duration exploration beyond low Earth orbit, sustainability concerns need to drive the early decision making.

Ignoring the continual repetition of the E word, who can argue with that? It’s motherhood. But none of his actual arguments, to the limited degree they exist, follow from it.

As with any space exploration endeavor, returning astronauts to the moon and onto Mars all starts with the rocket. Human space exploration to the moon and beyond requires a super heavy-lift rocket.

As usual, an assertion with no actual basis or argument, and in the face of NASA’s own internal studies that put the lie to it. And not just heavy lift, but SUPER heavy lift. Maybe even SUPER DUPER heavy lift. You know, in Bill “Ballast” Nelson’s technical term, a “big monster rocket.”

The Saturn 5 rocket, designed by Wernher von Braun and the brightest minds working at NASA and industry, remains to this day the world’s most powerful rocket ever launched.

Note again the argument from authority and hero worship, meant to impress people who don’t understand the history, programmatics, or technical issues. Note also the repetition of the word “powerful,” the mantra of SLS supporters, as though “power” per se is a useful metric of the utility of a rocket, and all others (e.g., cost, or reliability, or frequency of flight) can be ignored.

Today, NASA, Russia, China, and even new entrants SpaceX and Blue Origin, have reached the same conclusion as von Braun regarding the need for a super heavy-lift rocket. NASA is now nearing completion of such a vehicle, the Space Launch System (SLS). The SLS is even more capable than the Apollo-era Saturn 5 and the space shuttle, which was used to build the International Space Station. The SLS is the only rocket that can provide the needed lift and support the need dates for the deep space exploration missions, but is it sustainable?

Again, an assertion without an argument. And a misleading statement, because it implies that SpaceX and Blue Origin are building a heavy-lift vehicle because it is needed for “deep-space exploration missions.” But SpaceX and Blue Origin are not in fact interested in “deep-space exploration.” They are interested in developing and settling space. NASA thinks, or at least claims, it needs a big vehicle because it is afraid of orbital assembly. SpaceX and Blue Origin want big vehicles because they want to move a metric buttload of stuff into space, with thousands and millions of people living there.

I would also note that the continual invocation of von Braun’s name probably has him rolling in his grave. He was an advocate for fleets of reusable vehicles and space assembly. The only reason he took the route of the “super heavy-lift rocket” (gee, it’s almost as though the catch phrases are poll tested among the bubbas) is because he had the charge of getting a man to the moon and back in a decade, and that was the only way to do that. And note, that because he chose that route of necessity, it turned out to be unsustainable once the race had been won and there was no longer a need for such a vehicle.

Like the Apollo Saturn 5 launch vehicle, the SLS is expendable, and some may argue that a reusable launch vehicle would offer a more sustainable solution. While reusability appears to offer advantages, reusability also includes performance penalties when compared to an expendable rocket. A reusable rocket requires additional systems including thermal protection, flight stabilization, and the considerable fuel reserves needed to maneuver and land. Mission payload weight must then be sacrificed to offset the additional vehicle weight, and these penalties only increase as a rocket travels farther from Earth. To match SLS lift performance, a reusable rocket would need to be even larger and in the end become more complex and costly. The other option is to break the in-space exploration payloads into smaller pieces, but doing so adds further complexity, weight, cost to the payloads and increases risk to the program. Statistically, more launches and higher complexity increases the overall mission failure risk.

Note the lack of quantification of the argument. Yes, all those tradeoffs are true, but despite them, SpaceX has already flown a partially-reusable vehicle with payload equivalent to SLS block 1, whose first flight has now slipped beyond 2020. And it flies at a small fraction of the theoretical marginal cost of an SLS slight, let alone the amortized cost per flight, which will never be less than a couple billion (much more if one amortizes the insane development costs).

Then there is the issue of flight rate.

Yes, there is that issue.

Before starting SLS development, NASA anticipated the SLS flight rate would be as low as one flight per year. Under these conditions, sustainability necessitates streamlined production for affordability, a steady level of activity to maintain critical skills over the life cycle of the rocket for reliability, a stable industrial base, and the ability to incorporate product improvements as needed. NASA selected an expendable rocket architecture as the best design to meet their mission objectives and overall sustainability needs.

Like the original expectations for space shuttle, there are proposals for large reusable launch vehicles with a life expectancy of up to 100 flights. However, a reusable vehicle used at a low flight rate is counterproductive to sustainability. The combination of reusability and low flight rates creates production gaps between builds, discontinuities in workforce and loss of critical skills. The production gaps also pose additional challenges to attracting and maintaining a healthy supply chain. During the space shuttle program, suppliers were unable to provide parts later in the program due to loss of tooling, technology or processes that became obsolete due to the long gaps since their original production. This occurred because these processes and tooling were not needed each time the vehicle was reflown. These programmatic and industrial base factors are often overlooked, but essential for sustainability. A low but constant production rate of building one rocket a year, such as the SLS, serves to maintain key critical skills, keeps the industrial base supply chain active, and offers opportunities to fix problems, on-ramp new technologies or block improvements.

There are also additional costs and risks associated with reusability which should be taken into consideration. Successful reusability is built upon a detailed understanding of system degradation over the useful life. This requires additional analysis and design efforts, use of more expensive materials to endure the rigors of use, and an on-going test program to demonstrate and validate the design and manufacturing processes. If a significant change is made to an element or system of the rocket, then the test-experience clock for that is reset to zero. There are the additional recovery and refurbishment infrastructure and personnel costs to factor in as well. The bottom line is launch vehicle reusability comes at a cost and is not always the best solution for every scenario. Alternatively, it is important to look at opportunities for in-space hardware reuse, such as satellites, propulsion systems and habitats that operate in more benign environments than launch vehicles, and therefore do not have the extensive reuse overhead.

For human space exploration to be affordable, sustainable and therefore to succeed, every possible advantage to reduce cost must be studied and understood. New ideas for efficiencies must be solicited, explored and demonstrated to reach realistic and reliable solutions. Deep space exploration is a highly complex endeavor involving complex trade-offs in cost and risk.

Von Braun and the team that led the successful Apollo missions had it right. Although a lot has changed since the 1960s, the laws of physics and the architecture to conduct successful crewed missions to the moon remains unchanged. NASA is on the right track to support President Trump’s goal of returning astronauts to the moon in the early 2020s and preparing for even more ambitious missions to Mars. The Space Launch System is the right rocket for this mission.

14 thoughts on “That Doug Cooke Op-Ed”

  1. This op-ed makes some good points but in doing so illustrates the how government distorts all of the economic and manufacturing signals that the free market provides. NASA can’t do what SpaceX did. Also, the speculation over increased costs, weight, and overhead of reusability aren’t magic numbers, there are real number that can be applied and compared to the alternatives.

    Like the original expectations for space shuttle, there are proposals for large reusable launch vehicles with a life expectancy of up to 100 flights. However, a reusable vehicle used at a low flight rate is counterproductive to sustainability. The combination of reusability and low flight rates creates production gaps between builds, discontinuities in workforce and loss of critical skills.

    The author says that each SLS core constructed would make iterative improvements over the last. This is something that SpaceX was criticized for but it is also what made SpaceX successful. Why would it be ok for NASA to do this but not SpaceX?

    SpaceX has a higher volume of launches so engineers can learn more about the launch system over a shorter period of time, even with constant iterations. This creates a more skilled work force and when the system is mature, there are likely still roles for these workers doing testing, maintenance, upgrades, and constructing new cores. A slow manufacturing and launch rate doesn’t create a crack workforce.

    The problem for NASA is that they can’t get enough launches to do this process fast. SpaceX has the advantage of finding customers to purchase launches that allow for iterations and testing. NASA has to get money from congress but SpaceX gets money through paying customers and investors. There are still limitations in what SpaceX can spend but they are in control of generating funds.

    NASA can’t self fund and has no customers. This distorts all of the information used to make decisions on cost, production, and operations. NASA wants to build something that satisfies them and that limits what they build. SpaceX builds things to satisfy many different customers and that forces them to be able to meet many different sets of requirements while self funding development, having a high operational tempo, maintaining reliability, and turning a profit.

    NASA just can’t do this. They are a negative cash flow while SpaceX does all of the things NASA wants while being a positive cash flow.

    1. In short, NASA is forced to be pre-industrial, by the political means of funding them, In spite of its high technical competence, while SpaceX participates in the market networks of the worldwide industrial revolution far more fully.

      “When a society moves from allocating resources by custom and tradition (moderns read here, by politics) to allocating resources by markets, they may be said to have undergone an industrial revolution” Arnold Toynbee-1884

  2. “I have a different definition. I view affordability as the ability to financially enable large-scale space activity, both government and private. But large-scale space activity is the opposite of the Apollo mindset, to which too many remain in thrall.”

    I don’t think a government needs large-scale space activity, but it should be interested causing it to occur. I think mining lunar water, commercially, does not require large-scale space activity, but has to develop large scale space activity over longer term.
    I think human settlements on Mars, requires large-scale space activity, but NASA exploration doesn’t require large-scale space activity, and it should use commercial launch for at least a high percentage of total payload needed for the Mars exploration program, and don’t think just sending crew to Mars is a high percentage of total payload requirement of Mars exploration program. Though I think crew should be send to Mars with short duration of travel time or this increasing amount payload needed for crew aspect of the program. Or should increase amount payload needed to send crews to mars, but even allowing for that, the sending of crews to Mars is not large portion of total payload needed. And in terms of returning crew from Mars, that mostly about somehow having rocket fuel at Mars. And rocket fuel and other cargo/bases/surface vehicles/etc does not need to be sent to Mars fast.

    “As I’ve noted over the years, there are hidden assumptions in this paragraph. The first is that the purpose of human civil spaceflight is “exploration.” This is a fiction …”

    It’s fiction that NASA has been exploring space, but NASA is suppose to explore space- find resources which would allow increased use of space environment.
    The only other option is government making laws which allow the risk of exploration have a potential payoff/profit. And our laws are not anywhere close to being sufficient, currently. A zero tax penalty of exploration and exploitation of space resources, would be small step in that direction.
    The law assumes NASA will explore space- but it hasn’t.

  3. Nasa:
    “The SLS is the only rocket that can provide the needed lift and support the need dates for the deep space exploration missions, but is it sustainable?”

    This is completely foolish. A 130 ton to LEO is simply not enough, nor should NASA necessarily build a 130 ton to LEO.
    Instead NASA needs to dock and/or needs refueling in orbit.
    NASA should build and launch the 70 ton SLS. And it will be reviewed and determined how viable it is.

  4. Years ago at some space conference or another they were arguing all kinds of baloney about sustainability. I commented that something is sustainable if it is creating more value than is consumed in the making of that value. If more value is being consumed than is being created, then that process is not sustainable. Somehow, I don’t think they understood.

  5. Doug Cooke literally mis-defined “sustainability” to mean, “keep the shuttle workforce employed forever”. It’s then pretty easy to show that SLS is the best tool for that.

  6. In claiming without quantitative analyisis (of an eminently quantifiable problem) that super-heavy lift is needed for reliability, Cooke also omits that a rocket that flies a few times per decade is likely to be less reliable than one that flies a few times per year. Not only do the crews operating the smaller rocket keep their skills more current, but flight experience accumulates much more rapidly, allowing more failure modes to be discovered and fixed.

  7. Come to think of it, the ultimate irony of SLS may be that when NASA rolled out its SLS-based Mars architecture, the Evolvable Mars Campaign, it broke *everything* down to chunks no larger than 50 metric tons. SLS was still “justified” by the choice of a cis-lunar (specifically, lunar DRO) rendezvous point (although a few payloads were also injected directly to Mars). There might still some legitimate arguments about fairing sizes, but just introduce an intermediate rendezvous in LEO, and, voila, no super-heavy needed.

    1. With orbital rendezvous and propellant transfer in your toolkit, any payload you can get into orbit can be sent anywhere in the solar system. With the payload in 50 ton or smaller chunks, I believe that puts the job in reach of the Falcon Heavy. A super heavy lift launcher like SLS is then only justified if rendezvous in LEO is ruled out.

      On another note, what’s the delta-V penalty of having payloads assembled in near lunar space for trips to Mars, as opposed to LEO assembly?

  8. But SpaceX and Blue Origin are not in fact interested in “deep-space exploration.” They are interested in developing and settling space.

    I actually do wonder how many senior personnel at NASA are even comfortable with the idea of “developing and settling space.” There’s more than a little evidence of such skepticism beyond the four walls of the Office of Planetary Protection.

    At the Planetary Society, they don’t even bother to hide such misanthropism.

  9. Yeah it is just like you said Rand. Von Braun’s “The Mars Project” basically envisioned a mission with multiple launches and on-orbit assembly of the interplanetary spacecraft. With reusable shuttles.

    The reason the large rocket was designed was because of the many issues NASA had getting orbital docking to work properly, the lack of experience of in-orbit manufacturing, plus the lack of time to conduct all those launches and meet the schedule. It was quicker to launch it all in one go. At one point they even wanted a reusable lunar vehicle but the rocket for that was too huge, the Nova rocket. Eventually they compromised and we got the Saturn V.

    I have never been a fan of the BFR concept because I think using all chemical propulsion to settle humans on Mars is a stupid dumb idea. If you examine Von Braun’s group’s later Mars proposals they use ion-electric propulsion. Korolev’s group also went towards similar proposals. I think it is a dumb idea to use the same propulsion methods for both interplanetary travel and going up and down the gravity wells. Especially with all the improvements we have had with solar panels in both cost and efficiency since then.

    The idea to manufacture methane fuel in Mars sounds interesting in the long term but in the short run I do not think it is viable. Sure the atmosphere has a lot of CO2. But you still need the hydrogen from somewhere. Which I doubt will be as easy to get as scooping CO2 from the atmosphere. I think it will require a long time to get such an industry set up on Mars.

    Once SpaceX has dual bases in Texas and Florida which can launch the Falcon Heavy and another base in Florida which can launch the Falcon 9 do we even need the Frankenrocket? Perhaps we should actually try sending people to the Moon or Mars before deciding which ship design is best next.

    I am also skeptical about the extensive use of aerobreaking. Sure it’s nice to have for Earth-Mars travel. But it is mildly useless when traveling to places without an atmosphere like the Moon or Phobos and Deimos. If they really wanted to use aerobreaking I think something like the DC-X with the nose cone, moveable flaps, and vertical touchdown would be more viable than this design they are pushing. It is not their area of expertise. Just like I thought it was a bad idea for Rutan to make rocket engines, I think it is a bad idea for SpaceX to design a spaceplane.

    If there is one thing we have is time. If there is one thing we do not have is resources. We cannot keep disposing of rockets like they were paper tissues.

    1. BFR is designed to make SpaceX lots of cash by servicing the Earth orbit market. That is its first priority, and I expect that if they have to optimize it for that role at the expense of the Mars role, they will, and design a BFS variant optimized for Earth-Mars-Earth as they go.

      As such, I would not be surprised to see the BFS cargo variant ramp up first; if it meets SpaceX’s cost and reusability goals, it will almost immediately take over the commercial industry. This will give them the cash that they need to get the rest of the way to Mars, with or without tax dollars. The tanker may actually be the third variant, since it apparently isn’t going to be needed for the lunar flyby.

      In order to meet their ambitious timeline, direct solo flight to Mars is going to be the most effective method, since BFR is a) sized appropriately, and b) uses technologies that they are (or will be, by that point) comfortable with. As far as the H2 for the Sabatier reactor goes, that’s been carried from Earth in a tank since the first Mars Direct plan in the ’90s. I’d recommend reviewing Zubrin’s math on the process; the H is minuscule in mass compared to the C and the O, even accounting for the extra tankage involved. The H2 tank can be shrunk and/or deleted once sufficient water is being harvested in situ.

      Now, in the longer run, an ion-engine (or VASIMR, whatever) cycler makes a great deal of sense. A BFS variant could be optimized for that scenario (probably reducing tankage in favor of more cargo volume, with less refueling in LEO required). Depending on the design of the cycler, the crew-cargo ratio could also be fiddled with (e.g., if the cycler has ample life support and a grav deck). But, I am not aware of anybody even seriously working on a cycler at this time (or even the key parts, such as the power plant, engine, or grav deck). Therefore, it is in SpaceX’s best interests to not place a hypothetical vehicle using technologies that they are highly unfamiliar with themselves into their critical path to Mars.

      I would argue that a rover could potentially be a greater short-term asset than a cycler; specifically, an RV-sized, reactor-powered (Kilopower) model, which would allow SpaceX to move exploration duties from the BFS (via its landing site selection) to paired rovers designed for excursions that expand from hours to months as extra rovers and base personnel (to facilitate a rescue) accumulate. If the base could harvest enough H, C, & O, however, I could also see a BFS (or a stripped-down variant) used as a ballistic hopper for missions on the other side of the planet. Either way, consolidating landings allows for much faster construction of a permanent base, with less mass (hab space, rovers, etc.) abandoned on the surface or hauled back into space.

Leave a Reply

Your email address will not be published. Required fields are marked *