Stairway to Heaven

September 30, 2016

This was this week’s hype in the aerospace industry: Elon Musk presented his vision for reaching Mars and beyond. There are countless analyses and reviews of his presentation (here for instance for a technical one) weighting either in favor or against Musk.


The ITS on Europe. Credit: SpaceX

I got several times the question by friends, colleagues about what I , as an ex space propulsion engineer, was thinking about the feasibility of this vision. The bare answer is: I don’t know. I mean, there is not enough information in this presentation to evaluate the feasibility of the Interplanetary Transport System (ITS). I wonder how pundits can get an opinion on that. There has been countless Mars mission design proposals in the past. This one is not really different. It is both credible and far-fetched because written on the same model: you assess the requirements (in terms of costs, mission duration, target), you take the existing technology (to be credible) and you extrapolate it to meet the requirements (and it may look far-fetched or not, whether you are part of the proposal team or not). So basically, here, SpaceX develops the cost model to have almost routine trips to Mars (very cheap but it is a target – it makes sense to have something cheap if you want to “democratize” space); it takes the existing technology, a bit improved (the Raptor), the reusable launcher (complete reusability instead of only first stage) and it extrapolates the system (increase the number of engines, huge composite tanks,…) to be able to have a cheap transport. This is what was presented. There is no new concept, no really new technology.

So, how can you assess the feasibility of the mission? You cannot because there are missing data on the critical part: the execution. And in the space industry, the execution is the key from failure to success. What methods do they want to apply? How do they want to adapt their organization, their team, to meet the challenges? What new tools will they use to transfer this concept in reality?

If you think of it, SpaceX has not invented new technologies or radically new concepts of missions. They have taken existing ideas that other private companies have also taken (vertical landing – McDonnell and Blue Origin, space capsule with Orbital). I assume that NASA played an important role for the transfer of technology towards private company and that they didn’t need a huge effort of research and development. But what Musk did and this is a huge change, was to set up a modern organization managing both the system and the underlying technologies (propulsion, GNC, actuators), something that the Big Players like Boeing or EADS didn’t bother to do because technology is low-level. Adding to that modern IT tools to automate the manufacturing and production, it was possible for a relatively small team to develop and optimize in a very efficient way the construction of a new, partly reusable launcher and the associated space capsule. In the case of the Mars mission, there is no indication of what they will do in terms of organization, of how they will scale their methods to accomplish this challenge. For instance, they showed this big composite tank. Nice but how did they build it? The difficulty is to create an industrial robot which is able to loom that for big series while respecting the tolerances required. No word about that. Yet, this is where the feasibility of the project can be assessed. But this is also the heart of SpaceX. I understand that Musk does not want to reveals his trumps.

So, what about this presentation? What is the purpose of it if it is not to present the technical details of the project? In my opinion, there are two goals, one external, one internal.

Externally, you have to create the proper spirit for this kind of expensive endeavor. So this is a classical strategy when you want to sell a project where you know in advance that people are not convinced or concerned: you show far in advanced the most  advanced and incredible version of your project; the first time, people will say he is crazy; the second time, they will say no, the third time: “mmmm”, the fourth time: “why not…” and so on until they completely change their mind and say: “let’s go” and sign the check. People need time to get used to a crazy idea. Very probably, you will not get what you asked for at the beginning, but a limited version which will correspond to what you actually wanted. This is a very effective long-term strategy to fund new experiments. I can completely imagine that it is what Musk wanted to do. People will start to think and rethink and rethink. When the negotiations for the funding will arrive, the ground will be ready and people will be used to the idea. Probably, creating a new civilization on Mars is not really his ultimate dream (on Mars really? why not in Siberia? Or in North Dakota – I am kidding I love North Dakota). If he manages to get a first crew there under the flag of SpaceX, he will have written his mark in the sand of history.  Anyway, his rhetoric must revolve around the idea of colonization and not of exploration to avoid the major counter-argument of manned spaceflights: the robots! If he wants to send people to explore, his opponents will want to send probes which are probably more efficient for this work. But if he wants to create an interplanetary species, there is nothing to oppose: you touch the heart of mankind as a group of settlers.

Internally, the goal is easier to understand: to create the right spirit at work. You do not work on a rocket that sends communication satellites for whichever investment fund. You are working on an interplanetary crewed spaceship. This makes a huge difference. You are part of the conquest of space. In these conditions you can work 24/24 8 days a week.

To conclude, the presentation makes sense in terms of communication strategy, less in terms of feasibility of the concept. If you are not an insider, you have to believe or not. As an outsider, I believe my instincts and my centers of interest: I find chemical propulsion a bit boring 🙂 I admire these massive and loud engines like these old steam locomotives; they are jewels of engineering. But I am more attracted by electric system and other more exotic phenomena. I believe (! I have no way to demonstrate it yet) that there is a huge amount of energy to tap in and that the proper way to engineer them still has to be found. In addition, with cheaper and cheaper earth to orbit transports, it becomes to test riskier technologies. This will be a funny time!


The Wind rises for the engineers

July 15, 2014

The latest (and probably last) creation of Miyazaki is about the (fictionalized) life of the plane designer Jiro Horikoshi, the creator of the Mitsubishi A6M Zero, which gave nightmare to many US pilots during WWII. It was a huge success in Japan.

I will be honest from the beginning: this is not my favourite Miyazaki: the magics does not work and I do not know exactly why: perhaps the character of the hero is not enough worked out, a bit too dull. Or the tragic love story, the purpose of which is not clear; he wanted perhaps to show that engineers have an heart in addition to a brain.

Yet, it is Miyazaki and the film is still a masterpiece. I have three main elements that attracted my attention and where I thought “yes, this is like that!”.

  • first, the dreams as a child: which aerospace engineer did not have dreams of sky or space when he was a child? Which enginerr did not imagine the perfect machine in his daydreams. You dream, you study, you take the low level jobs in an aerospace company and you climb the ladder. 
  • Second, the relation with the hardware. There are two beautiul scenes (for an engineer): On his first day at Mitsubishi when he asks whether he can see the assembly of the plane in the workshop; the foreman is happy to see that at least one guy from the design office is interested in the hardware. And the second scene where the design team receives a sample of the new ultra-light aluminium alloy (I wonder if it is the 7075 developed Sumitomo Metal). and they are all bewildered by this apparently mundane rod of metal.
  • And to finish, the complex relations between the dreams of an engineer and the hard reality of a war. It is of course controversial: we do not know exactly what really happened in the mind of Horikoshi. He is depicted in the film as rather little concerned by the  military aspect of his job.


All in all, I would recommend the film if you are engineer, especially to watch the lost art of the slide-rule.  

The European SpaceX

June 24, 2014

You have probably read the news that Airbus Space and Safran wanted to team up to be more competitive against SpaceX. I am not sure that it is the right solution to develop a future European Falcon. First, they remain a part of their mother companies, which feature, because of their size,  a huge inertia in terms of development. Second, they will have a problem of culture: it will be a hybrid between a system designer and an engine developer with very different methods.  SpaceX is from the beginning a homogeneous company integrating both the system and technology in its culture.

In my opinion, the only solution is to create in Europe the conditions for entrepreneurs (and very bright ones) to create their own space startup. These conditions do not exist for the moment. And it will be a hard task. Airbus, Safran, Thales will block any attempts and they have a lot of weight among politicians in charge of the space program: they recruit their staff from the same pool. It was also the case in the US with Lockheed, Boeing and co. The big trump that Elon Musk played was the Silicon Valley, something that does not exist at all in Europe. SpaceX was able to get the support, the benediction and the image of a Californian startup and to use it to install its political credibility. There is no such lever on the Old Continent and this will be the major difficulty.

In addition, we have here a reduced culture of risk-taking: your diplomas, your position in a well-known company insure you recognition, not being part of a startup even if you build space rockets.

The last problem is the European Space Program itself: it is not ambitious; it has never been ambitious. SpaceX arrived at a point where NASA was lacking of funding but it was still ambitious. So they were eager to accept any viable solution; SpaceX was a solution; they took it to insure an ambitious program. If an European startup goes to ESA and say: we have the way to build a cheap launcher but we need your technical support, the answer will be: “What for?”.

There is no easy solution; but maybe, there is somewhere an European Musk with a high sense of strategy and a genial technical background and he will soon show us his hand.

Cybernetics is the future of space transportation.

January 2, 2012

Or not.

NASA: (one more) Space Launch System

September 15, 2011

So, NASA announced yesterday a plan for a new rocket, tentatively called SLS; this is the announcement. What has this announcement to offer? a nice video (with 3D realistic models of the rocket) and a fun facts sheet. Well, I must say, this sheet is the most interesting part of the announcement because we have at least some figures to have a glimpse at the technical capabilities of the launcher. Otherwise, the picture of the rocket has not the slightest interest.

There is some buzz about the announcement, but not much: most people seem to think the same: well, “one more design, but will it be built one day? That’s far from being sure”.

This new concept looks really like  a pure PR show: we see so many pictures of new rockets, new designs, but they all are basically based on the same principles. Nothing really new, nothing really inspiring, except for Space-X: their rockets are not new in design (although the idea to cover the stages with thermal shields to make them reusable is pretty clever, I am looking forward to seeing if they manage to find a balanced mass budget), but the way to build them, the optimization of the assembly processes, the fast pace of development are motivating.

And instead of seeing a model of the rocket, I would like to have useful technical figures: mass budgets, fuel cycles, comparison with previous rockets, flight scenarios. Well, all figures that explain why this design was chosen.

PS: I take here the example from NASA, but it is the same for most of “new concepts” presented by agencies or space companies. They are most of the time PR operations with minimal technical background.

NIAC technologies of the future

August 10, 2011

I have listed in a previous some of the interesting projects funded by the NIAC in its phase-1 programme. I would like to detail some of these technologies and try to understand why they can be key elements in a revolution of the aerospace sector. In addition, I would like to put references on this topics as a ground for further analysis. In this review, I will be limited by the lack of accuracy of the different project’s titles; therefore, I will be forced to take some basic assumptions and any corrections of these assumptions will be welcome.  I will focus on this post mainly on propulsion:


One big unknown is the so-called “ambient plasma wave propulsion”, an original name proposed by J. Gilland from OAI. Looking at previous report (or even better, this one) from him, I think that this propulsion is based on the concept of helicon waves (but the title of the project is not precise enough to confirm it). The benefit of this method is to produce higher density plasmas than with the other types of plasma thrusters for a given level of power. This system can work as a rocket with the propellant on-board, or even clever, as an “air-breathing” engine using in-situ propellant, a kind of electrical ramjet. One advantage of this latter method is described in this document. One big pro is low altitude stationkeeping, using the ambient atmosphere as a propellant to make up the drag (I like the term  “thermosphere cruiser”). The same principle should be at stake in another NIAC project: “Atmospheric Breathing Electric Thruster for Planetary Exploration”.

Some more details can be found in this report: Propulsion Mechanism in a Helicon Plasma Thruster (N. Sinenian – MIT).

Concerning the project on Nuclear Propulsion through Direct Conversion of Fusion Energy, you will find a better description on Next Big Future and on the website of MSNW.  The principle is the creation of plasmoids, which are ring shaped plasmas with an internal reversed field (a bit like the Reversed Field Pinch used for fusion).

Aneutronic fusion propulsion belongs to the wide range of fusion concepts. Newspapers have recently focused on it because of the presentation of J. Chapman at the latest SOFE conference. The problem of “classical fusion” (for instance with tritium) is that a lot of energy is lost in fast 14MeV neutrons which are, in addition, dangerous for hardware and crew. Aneutronic reactions are less efficient but most of the energy produced can be harnessed. In the end, the energy budget could even present some gain.


There was a proposal called ‘Ultra-Light “Photonic Muscle” Space Structures’. But its author, Joe Ritter mentioned that the project was actually titled ‘Ultra-Lightweight Photonic Muscle Space Telescope’. This has to do with optics and not with structure. The idea is based on nanotechnology and the use of photoactive isomers which are layered in the primary mirror and actively controlled by lasers. Thus, the purpose is to replace the mechanical actuators of the active optics (like on the VLT) to get a more accurate control of the mirror surface. Please refer to his presentation for further details.

NIAC Phase 1 selection

August 9, 2011

To celebrate its rebirth, NIAC, the NASA Institute for Advanced Concepts grant 100k$ to a list of selected projects. The principle of funding very preliminary ideas to assess their potential is very interesting.

I am trying out to get further details on each project to understand what they are all about. But I have already noticed some concepts which are of interest for me:

  • Enabling All-Access Mobility for Planetary Exploration Vehicles via Transformative Reconfiguration
  • The Potential for Ambient Plasma Wave Propulsion: I wonder whether it is something like this concept. Probably with a mix of this concept of helicon wave thruster.
  • Atmospheric Breathing Electric Thruster for Planetary Exploration
  • Entanglement-assisted Communication System for NASA’s Deep-Space Missions: Feasibility Test and Conceptual Design
  • SPS-ALPHA: The First Practical Solar Power Satellite via Arbitrarily Large PHased Array
  • High-temperature superconductors as electromagnetic deployment and support structures in spacecraft
  • Non-Radioisotope Power Systems For Sunless Solar System Exploration Missions
  • Ultra-Light “Photonic Muscle” Space Structures
  • Printable Spacecraft
  • In-Space Propulsion Engine Architecture based on Sublimation of Planetary Resources: from exploration robots to NEO mitigation
  • Metallic Hydrogen: A Game Changing Rocket Propellant
  • Nuclear Propulsion through Direct Conversion of Fusion Energy: the purpose here is to directly use the energy coming from the fusion reaction instead of converting it in electricity. That reduces the number of architectures but this choice is obvious in terms of mass budget.
  • Steering of Solar Sails Using Optical Lift Force
  • Aneutronic Fusion Spacecraft Architecture
  • Radiation Shielding Materials Containing Hydrogen, Boron, and Nitrogen: Systematic Computational and Experimental Study
  • Meeting the Grand Challenge of Protecting Astronaut’s Health: Electrostatic Active Space Radiation Shielding for Deep Space Missions
  • Radiation Protection and Architecture Utilizing High Temperature Superconducting Magnets
I have several comments on this list:
  • try to google these subjects: you will see that most of them are poorly document: it is a sign that they have received untill now little attention and deserve more funding to have a better idea of their potentials.
  • There are a lot of items which are oriented towards propulsion: this is indeed the major problem in advanced space engineering and it is acknowledge here.
  • There are also a good percentage of items dedicated to radiation shielding: NIAC shows clearly here that one main target is manned mission and even manned mission in deep space.
  • Curiously there is nothing on cooling systems: I however think there are a lot of things to do in this area; indeed no power system has a high efficiency; a large part of the power has to be evacuated from the spacecraft and passive thermal systems have a heavy mass cost. What about new solutions?
  • Solar Power Satellites are once again back on track! Without them an advanced program would probably not look like serious. I still wonder why they are listed: I think that there exist enough reports to explain the pros and cons and describe which key technologies are requires to enable their development. No further assessment is needed.
All in all, I am curious to see how this program will be managed and what the outputs will be. I just hope that the reports will not be thrown away once the conference in 2012 is done.

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