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Breakthrough Concepts: A Propulsion Overview

Speaking at last fall’s International Astronautical Congress in Prague, Tau Zero founder Marc Millis offered a condensed summary of the present state of the art in advanced propulsion physics, summarizing a variety of approaches and next-step questions from the book he co-edited with Eric Davis called Frontiers of Propulsion Science (2009). He’s now written a paper based on the presentation. It’s a useful distillation of an extremely detailed work (739 pages) and well worth scanning now that Millis has made it available on the arXiv site.

Quite a few propulsion concepts have gone through the early stages of the scientific process, with problems defined, data being collected and hypotheses formulated, and Millis also refers to those cases where ideas have progressed into the testing stage. He’s fascinated with the idea of using investigations into broad issues of cosmology to focus in on something far more utilitarian, the possible relevance of new observations for spaceflight. From the paper:

While general science continues to assess cosmological data regarding its implications for the birth and fate of the universe, a spaceflight focus will cast these observations in different contexts, offering insights that might otherwise be overlooked from the curiosity-driven inquiries alone. Homework problems to help teach general relativity now include warp drives and traversable wormholes. Even if there are no spaceflight breakthroughs to be found, adding the inquiry of spaceflight expands our ability to decipher the lingering mysteries of the universe.

Focus on the ‘Space Drive’

The approaches gathered in Frontiers of Propulsion Science are too numerous to list here, but let’s focus for a moment on the issue of space drive physics. A space drive is the umbrella term used to describe the interactions between a vehicle and surrounding space to induce motion, the key point being that such a technology, if ever developed, would eliminate the need for propellant. That’s a big issue — if we could move a craft in this way, we would be dropping the energy requirements from exponential to squared functions of trip velocity, opening up a wide range of mission possibilities we simply cannot achieve with rocketry or space sails.

Notice that the space drive is fundamentally different from what is more and more known as a ‘warp’ drive, the point being that the space drive interacts with spacetime rather than warping spacetime. Quoting Millis again:

Warp drives and wormholes are rooted in the Riemannian geometry of general relativity, where sufficient energy densities can warp spacetime analogously to how a huge gravitational mass bends spacetime. In contrast, most space drive concepts begin with Newtonian representations where the operative goal is to interact with reaction mass embedded in the properties of spacetime. This also implies, therefore, that space drive concepts will be light-speed limited since they operate within spacetime.

In other words, a warping of spacetime, if possible, would allow the craft to take advantage of the fact that there is no speed-of-light restriction when it comes to the expansion of spacetime itself (a notion that draws on cosmic inflation in the Big Bang era). The space drive is a different animal, and it compels a different kind of research. The primary issues are conservation of momentum and net external thrust, with the concept raising huge questions about the sources of inertial frames, the nature of the quantum vacuum energy, and the physics of photon momentum in media.

Our understanding of inertial frames is not complete, and various versions of Mach’s principle exist in the literature — speculating that inertial frames are the result of surrounding matter — with issues that remain unresolved. Nor is our understanding of vacuum energy complete. In fact, says Millis, “Depending on factors chosen for the calculation, the equivalent mass density of the quantum vacuum energy can span from the insignificant 10-26 kg/m3 to the enormous value of 1098 kg/m3.”

From Quantum Physics to Cosmology

The extension of quantum physics to cosmological scales is obviously a work in progress, with numerous approaches still in play. Will practical applications one day flow from their reconciliation? We can’t know, but Millis believes that adding the desired propulsion and power goals to these studies offers a useful additional perspective.

Over three dozen concepts toward breakthrough propulsion and power are addressed in this paper in a complex table that reflects the content of Frontiers of Propulsion Science, categorized by the challenges they address and their respective methods, and drawing on the ‘grand challenges’ addressed by NASA’s Breakthrough Propulsion Physics project, which Millis ran from 1996 to 2002. His paper goes on to offer up a challenging set of approaches matched with ideas about the unfinished physics they provoke, along with suggestions for next-step research. Many of these are general themes rather than specific tasks — to cite a few from his lengthy list:

  • Explore vacuum energy experiments using negative index of refraction materials, ultra-high electrical carrier density materials and superconductors
  • Determine if measurable effects are possible using ultra-high intensity tabletop lasers to test the space-warping assertions from general relativity
  • Independently repeat or devise new experiments to explore Martin Tajmar’s unconfirmed observations of inertial frame dragging related to rotations of ultra-cold matter
  • Revisit prior theoretical attempts to mature Mach’s principle into testable theories, but now including the following natural observations that were not known at the time of those earlier attempts: the absolute frame reference from the Cosmic Microwave Background radiation, anomalous trajectories of deep space probes, and the anomalous observations that lead to the Dark Matter and Dark Energy hypotheses.

And so on. Systematic and rigorous research can flow out of all this, but we have no way of knowing whether future discoveries in these areas will reveal new methods to help us cross interstellar distances at speeds faster than we can create through presently understood methods. The challenge is open-ended and energizing. Adds Millis: “Progress is not made by conceding defeat. With a combination of risk-taking vision and impartial rigor, useful, reliable results will accumulate.” Those results may or may not offer us a route to the stars, but they will help us discover things about the universe we need to know, a worthwhile outcome in the best tradition of scientific research.

The paper is Millis, “Progress in Revolutionary Propulsion Physics.” Preprint available.

Related: My article “Tau Zero Takes Aim at Interstellar Propulsion” is now available on the Discovery News site.


Comments on this entry are closed.

  • kurt9 January 10, 2011, 14:02

    Its a nice paper. Maybe someday I’ll pony up the $100 to buy the book. I was not aware that there were so many approaches to this stuff. I was aware of three of them. First is Woodward’s Mach effect approach. Second is the Heim theory approach. The third is Puthoff, Haisch, and Rueda’s quantum vacuum fluctuations approach. These three seem the most plausible to me.

    The cost to develop test apparatus of some of these does not appear to be that expensive. Woodward and March are making new versions of test apparatus to test their theory. An apparatus to test bosonic coupling for a Heim-Lorentz thruster also would be of reasonable cost. However, the inability of other researchers to confirm Tajmar’s results suggests that bosonic coupling does not exist. Testing the fermionic coupling approach would be a lot more expensive due to the need for advanced superconductor materials (which now exist, but are expensive) as well as the generation of high Tesla magnetic fields.

    I don’t know of test approaches for quantum vacuum fluctuations. I have read a recent paper by Woodward that presents a convincing argument that quantum vacuum fluctuations do not exist (the effects are due to Mach effect) and that this approach is a dead-end.

    In any case, I think research into such advanced physics ideas is the proper approach for Tau Zero. You guys should start a collection of downloadable copies of all of the relevant papers.

  • John Q January 10, 2011, 16:23

    Random thoughts:

    Robert Forward did a wonderful little article in Analog 30 years ago titled “Spin Drive to the Stars.” The reasoning-by-analogy Forward used was suspect (as reasoning by analogy always is) but that ideas were so fascinating that it is a pity there has been no credible research into the idea since.

    Faster that light or magic drives are as far as I can tell are not going to happen given our current understanding of space-time. Einstein is merciless: either the energy requirements are mind-numbingly beyond any conceivable technology, or they are flat out prohibited by the usual paradoxes (resulting from the well-known faster than light == backwards in time business.) But, once we have a quantum theory of gravity that may change. In other words, we need a new theory of space-time for there to be any hope of pulling FTL off. Not an easy thing to do.

    I looked into “the Heim theory approach” and it seemed to me that if it is true, there should be some clear observational consequences on/in Jupiter, but I could find nothing in the way of such work. That Heim theory may generate potentially testable hypotheses (or be subject to experiments) is a good thing but I ultimately found it wanting in credibility. As usual, I hope I am wrong.

    When I first read about “Martin Tajmar’s unconfirmed observations of inertial frame dragging related to rotations of ultra-cold matter” (in New Scientist) I was just thrilled. But again, nothing seems to have come of it.

    Our top priority should be to find a really cheap way to get out of the gravity well. Cost is killing space flight.

  • kurt9 January 10, 2011, 18:30

    “Our top priority should be to find a really cheap way to get out of the gravity well. Cost is killing space flight.”

    No kidding.

  • Kenneth Harmon January 11, 2011, 2:22

    To Marc Millis,

    When you were at NASA and doing your Breakthrough Propulsion Research, how much do you think you can have accomplished if you and your team had been funded at ~$50 million per year for 5-7 years? I am trying to get some sense of scale of what a serious Breakthrough Propulsion Program would look like in the early phases. Obviously, if something major was discovered the scale would move to the Billions of dollars very quickly. However, in the early phases would ~$50 million per year yield allot of good science over a 5-7 year period? Also, did you ever look at Teleportation as a means of breakthrough Space travel. We may never be able to Teleport people without killing them, but Teleporting large objects seem to be very viable over the next 100 years.

  • Paul Gilster January 11, 2011, 8:40

    Kenneth, Marc is currently traveling on TZF business — he’s in California for the DARPA/NASA-Ames ‘100-yr starship’ meeting — but he should be able to answer this question in a few days.

  • Eniac January 11, 2011, 21:09

    If we could move a craft in this way, we would be dropping the energy requirements from exponential to squared functions of trip velocity, opening up a wide range of mission possibilities we simply cannot achieve with rocketry or space sails.

    Not quite. This might work approximately for solar or nuclear interplanetary craft, but for nuclear powered interstellar craft, the fuel would weigh just as much as the propellant, and we would not gain much by doing away with propellant.

  • kurt9 January 11, 2011, 23:48

    “Einstein is merciless: either the energy requirements are mind-numbingly beyond any conceivable technology, or they are flat out prohibited by the usual paradoxes.”

    Actually both Woodward’s interpretation of Mach’s Principle as well as Heim Theory are derived from and are compatible with GR. There is also a version of quantum vacuum fluctuation theory that is also compatible with GR. Anything that is compatible with GR has a chance of being real.

    Also, I would not discount Heim theory just yet. Although bosonic coupling appears to be invalid, the same cannot be said for fermionic coupling (the approach requiring the high T magnetic fields). The issue is still open until falsified by experimentation.

    I regard all other concepts of FTL to be spurious as they are not compatible with GR.

  • Eniac January 12, 2011, 19:47

    This reminds me of the “Flashlight drive”, aka photon rocket or Rubbia’s thruster. In this paper:
    Derosa and Maccone appear to show that such a drive, which does not require reaction mass and should thus qualify as a “space drive”, performs competitively with antimatter for a trip to Alpha Centauri. Compared with other star drives, this one seems almost trivially easy to build: Stick a very hot solid state nuclear reactor at the focus of a reflector/lightsail. It requires no new physics and very little beyond current technology.

    As I see it, the idea is to exploit the dreaded thermalization and use blackbody radiation to obtain near 100% conversion of nuclear energy into ultimate-ISP propulsion. Another way to describe it: “Bring-your-own-sun solar sailing”.

    Should we consider this for Icarus, or am I missing something?

  • John Q January 12, 2011, 22:08

    kurt9 —

    > Actually both Woodward’s interpretation of Mach’s Principle* as well as Heim Theory are derived from and are compatible with GR. . . . Anything that is compatible with GR has a chance of being real.

    I agree that being compatible with GR is, given our knowledge, a good thing. I hope I didn’t imply otherwise. But we still have a lot to learn and major revisions of our understanding of space-time that would render GR only a limiting case cannot be ruled out. Indeed, in my thinking, are likely.

    > The issue is still open until falsified by experimentation.

    I am agnostic about Heim Theory. I read Heim’s foundation paper and articles about Heim theory but I honestly cannot say based on my understanding it is “derived from or compatible with GR.” That is likely just a statement of my own ignorance, however. As long as Heim and Woodard generate testable hypothesis, that is all I care about and on that I gave them both a pass.

    * Mach’s Principle: From Newton’s Bucket to Quantum Gravity (ISBN: 0817638237 / 0-8176-3823-7) Barbour, Julian; Pfister, Herbert. I counted about two dozen versions in this book on Mach’s Principle, which people may not know has a long, torturous, and contentious history. Even Einstein, after initial enthusiasm, appeared to conclude that it was more trouble than it was worth; Mach seemed to think he was misunderstood regarding it; and whole journals came to ban discussion of the thing.

  • kurt9 January 13, 2011, 0:07

    The most significant point about GR is its requirements for background independence (Lorentz invariance) with regards to the space “metric”. This characteristic excludes electromagnetic ZPF or other quantum vacuum schemes that are not background independent. This, not the lightspeed barrier, is the major bugaboo that makes the prospects for FTL so difficult.

    GR does allow for the possibility of traversible wormholes.

  • Daniel January 13, 2011, 0:38

    i know that youtube video isn’t a good scientific information source but was watch this videos of 1 at 19 i would like ask the opinion of scientist like Marc Millis and Paul Gilster or anyone than know more about of this topic:

    Anti-Gravity / Cold Fusion Explained In Detail: A New Era In Physics Pt. 1 of ?


    is the theory of this guy make any sense?

    by the way I’m graduate student of physics, I’d to know what is the steps to be a Physics of propulsion more exact in exotic propulsion like wordward experiments,gravity control,relationship between superconductor and gravity,wormhole,warp drive etc… in what area i must be a specialist,quantun gravity? general relativity? electromagnetism? i want be experimental physicist,i want try put this things out the paper.

  • James M Essig January 13, 2011, 0:51

    Hi Paul;

    A vacuum latent energy density of 10 EXP 98 kg/(meter EXP 2) would be awesome. Consider that the vacuum energy fields may be continuously regenerated and that the value of 10 EXP 98 kg/(meter EXP 2) is based in part on the assumption of Planck Mass black holes continually coming in and out of existence. The refresh time for the virtual black hole creations would be about equal to the Planck Time at [5.39 x (10 EXP -44)] seconds. In one second, about (10 EXP 98 kg)[1.855 x (10 EXP 43)][9 x (10 EXP 16)] Joules might be derived from the ZPF. This is equal to 10 EXP 88 times the real mass energy content of the visible universe.

    If we assume that densities higher than the Planck Mass and Energy Densities are possible and that 4-D space-time differential volumetric elements can be smaller than [Lp EXP 3](Tp) or about (10 EXP -149)(meter EXP 3)(second), the ZPF may produce an even greate volume specific power out put.

    Note that the Planck Length and Planck Time are {[[h/(2 π)] G]/[C EXP 3]} EXP (1/2) and {[[h/(2 π)] G]/[C EXP 5]} 1/2 respectively.

    The Planck Mass = Mp = {[h/(2 pi)]C/G} EXP (1/2) = [2.17644(11) x (10 EXP – 8)] kilograms. The Planck Mass Density = {[C EXP 5]/{[h/(2 pi)] (G EXP 2)}} = [5.1 x (10 EXP 96)] kilograms/[meter EXP 3]. The Planck Energy Density = {[C EXP 7]/{[h/(2 pi)] (G EXP 2)}} = {[9 x (10 EXP 16)] [5.1 x (10 EXP 96)]} Joules/[meter EXP 3].

    Some very indirect subtle experimental results offer a glimps that the Planck Length might not be the smallest spatial distance of resolution as the experiments have indicated the Planck Length as the upper boundary. I can try to did up the results but It will take some web searching.

    We can also consider the prospects of ZPF energy densities with respect to a highly inertial reference frame. If a space craft was to some how reach a gamma factor of 1 million which I have faith can be accomplished but it will likely takes Centuries of R&D, perhaps the harnessable zero point field energy based power would be equal to (10 EXP 98 kg)[1.855 x (10 EXP 43)][9 x (10 EXP 16)] Joule/seconds = [1.4 x (10 EXP 158)] watts ship frame.
    The force of a photon propulsion system with respect to the ship frame could be [[1.4 x (10 EXP 158)]/[3 x (10 EXP 8)]] Newtons = [4.666 x (10 EXP 139)] Newtons. A 1,000 metric ton craft under such a drive would accelerate at [ [4.666 x (10 EXP 139)] /(10 EXP 6)] G’s ship frame or [4.666 x (10 EXP 133)] G’s. Gee Weez!

    This power output would be well above the Planck Power of
    Pp = [C EXP 5]/G = [3.6289 x (10 EXP 52)] watts ship frame so some sort of antigravatic gravitational field cancellation mechanism would be needed for the energy extraction system not to immeadiately convert to a black hole state.

    Space drives in some ways might permit more extreme space travel than space time topology deformation systems such as warp drives or wormholes by virtue of at least permitting ensemble gamma factors as a mathematical extreme. This would permit the space craft to travel an ensemble of light-years in one Planck Time Unit ship time and an ensemble of years into the future in one Planck Time Unit Ship time. For the ship’s crew, the journey would be epic and the boys back home would be proud of the courageous crew undertaking such a mission.

    As to how to cloak the space craft from interstellar and intergalactic drag and collisions, I will leave thespecific engineering details and blueprints of such for untold generations of humans to follow.

  • Daniel January 13, 2011, 1:03

    Ah other thing there many interest scientific papers than come out recently of propulsion and other things of interest:

    nextbigfuture on: Repulsive casimir force from metamaterials


    Repulsive Casimir Force in Chiral Metamaterials


    Comment on “Repulsive Casimir Force in Chiral Metamaterials”


    Repulsive Casimir forces with finite-thickness slabs


    Microstructure Effects for Casimir Forces in Chiral Metamaterials


    and about negative energy this is a interest scientific paper:

    Experimental Concepts for Generating Negative Energy in the Laboratory


    and the nextbigfuture talk about nuclear propulsion:

    Richard Dell Jr who is developing nuclear fusion propulsion is interviewed by Sander Olson


  • kurt9 January 13, 2011, 13:38

    Actually, there is a guy from Rice University who is working with a theory of quantum vacuum fluctuations where he used the GR based estimate for the energy density of vacuum, which is only 10 EXP -26 Kg/m2. This is very different from the QVF proposals that are based on an enormous energy dense ZPF.

  • Marc G Millis January 14, 2011, 13:28

    Thank you all for your enthusiasm!

    First, regarding what is, or is not, covered in that report, much of what was discussed above is already in the report and the “Frontiers” book. For examples, Forward’s “spin” idea is now labeled as “Dipole…” and that wonderful book suggested by john Q (Mach’s Principle by Barbour & Pfister), is indeed cited in our “Frontiers” book. There are MANY details that do not fit into a 10-page summary.

    Regarding Woodward, Heim, and Tajmar – works that get mentioned in these comments numerous times, let me just say this:
    – WOODWARD and his collaborators continue to make progress and publish their findings in a way that is open for examination and critique. I continue to watch their progress and am gratified with their efforts to be rigorous, open-mined, and accessible.
    – HEIM’s work, at least so far, has only been hyped by its proponents rather than advanced. Plenty of grand assertions have been published, but none of the derivations or other details to support those assertions have been articulated. That situation is disturbing. I am still awaiting the emergence of such details rather than the recurring hype.
    – TAJMAR is in the process of changing jobs and his experiments are still untested sufficiently by others to help determine what is really going on with the observations. I am quite curious as to how that will turn out when experimentation and reporting resumes. I keep my eyes on this one too.

    Kenneth, regarding your questions about what $50M/yr x 6 years would have done… The consequences of that much investment is beyond my predictive power, but what I can tell you is that for $6M/yr, we could begin to chip away at ALL the options that are already in the queue. That level of effort could at least check the next make/break issues and help us decide what areas are more promising that deserve deeper investments.

    I would be remiss in my duties if I did not use this opportunity to ask for such levels of funding. We recently compiled a list of next-step tasks covering a broad swath of possibilities in each of these categories: (1) What’s Out There? (2) How to Get There? (3) Human Relevance (4) Education. I would love to get that list out in the open, but there are many administrative duties that must proceed such details (admin duties are a substantial burden).

    Please donate. We are standing by to implement these works, once we’ve accumulated enough funds. And stay tuned to Centauri Dreams for that progress.

  • Marc G Millis January 14, 2011, 13:38

    Regarding educational pursuits, here is the general advice I give: Study either physics, electronic engineering, or aerospace engineering – whichever feels most comfortable with your natural attributes. During this time and after you get whatever job you can, keep abreast of the literature, and do what you can on the side. Once you have a substantive question, idea, or observation, write it up and submit it to a journal such as the Journal of the British Interplanetary Society. Then, based on the feedback – whether a rejection letter or comments on your paper, decide the next best step. Then do that, iterate, and continue to advance. Eventually, if you’ve got what it takes, your works will gain notice and start to have an impact on the overall progress.

    That is all I can offer now. To date, there are no schools that cover propulsion physics, but Embry Riddle does cover space propulsion in general at a level broader than many universities. To date, we have not compiled a list of pertinent universities – that is one of the tasks we’d like to do once sufficient funding is secured.

    Thanks for asking and best of luck in becoming a pioneer!

  • Duncan Ivry January 15, 2011, 22:27

    Reading the interesting article of Marc Millis, I think there is some hope, that he will get from *merely* theoretical considerations to more well-founded ones supported by real physical experiments (some here may remember me having expressed my critique a little bit more detailed in the past).

    Now I see e.g. the shift from warp drive to space drive which is “light-speed limited” since it operates “within spacetime”. As far as I can see, this research path is to a greater degree based on physics (and not on fantasy physics). I welcome this very much.

    I would appreciate very much if Marc Millis could tell more about experiments — good old, down to earth, substantial, valid, physical experiments — having been performed already. After many years of theorizing, its really time. This is a crucial point.

    One thumb up for Marc Millis.

  • Marc G Millis January 16, 2011, 10:50

    The recent article is a just summary of the book, where even more experimental approaches are spread throughout its pages. Both the experimental and theoretical works have been in there all this time, available to the active readers. One of the many ‘to-do’ items is for us to extract and propose those specific next-step experiments for funding. I have two labs available where I could subcontract such work if there was funding. And of course, our findings would be published.

    If you are particularly interested in the experimental side, any support to conduct such experiments would be greatly appreciated.


  • Ronald January 19, 2011, 16:24

    Fascinating again, a few comments:

    – Heim, as expanded by Dröscher & Häuser does allow for FTL travel in a kind of temporary higher dimension (if I remember well, they expanded Heim’s 6 dimensions to 8 or so).

    – I am pleased to also see Raymond Chiao’s work mentioned in the paper, not as well known publicly and not mentioned by anyone in the comments here. His work is on gravitational mirrors, read about it in early 2009, but I do not know of recent developments.

  • Tim January 21, 2011, 19:47

    I think I read this at just the right time. I’ve also been thinking about how to work in propulsion of one sort or another. I’ve got a degree in mechanical enigineering from the University of Newcastle, Australia, but I’ve never really studied advanced physics in any proper detail.

    Do journals like the JBIS usually take unsolicited paper submissions from amateurs? The BIS website has a few notes for authors, but nothing really on who can submit.

  • Kelvin Long January 22, 2011, 11:13

    Hi Tim,
    if you want to get into propulsion physics/engineering the best way forward is to read a couple of general books on the topic, then perhaps a couple of general papers then pick the topic you find most interesting. Could be laser beaming, fusion, thermal rockets, microwave propulsion, ramjets, FTL….there really is a lot of stuff out there. You need to learn the basic terminology first, such as exhaust velocity, specific impulse, mass ratio….e.g. study the ideal rocket equation if you don’t know it already.

    For elementary books I would recommend:

    ‘The Starflight Mannual’ By Greg Matloff (contains calculations)
    ‘Interstellar Travel & Multi-Generation Space Ship’ edited by Yoji Kondo.
    of course our very own Paul Gilsters ‘Centauri Dreams’ is a good overview too with good focus on the human story of trying to do propulsion research.

    For a couple of basic papers I would really recommend one of the following as good introductions:
    (1) “A Program for Interstellar Exploration” by Robert Forward, published Journal of the British Interplanetary Society, Volume 29, pp.611-632, 1976

    (2) “Ad Astra” by Robert Forward, published Journal of the British Interplanetary Society, Volume 49, pp.23-32, 1996.

    (3) “Interstellar Travel: A Review for Astronomers” by Ian Crawford, published O.J.R.astr.Soc, 31, pp377-400, 1990.

    You can obtain the JBIS papers through the BIS web site by emailing them, only around $10 per paper.

    Once you have picked the propulsion topic that you find most interesting, learn everything about it, read anything you find on it from papers/books/web. Then you will build up a knowledge of all the unsolved engineering/physics problems, and any of these can form a paper potentially. If you need ideas, contact me through either Paul Gilster or the Project Icarus web site and I will gladly give you some.

    Regards JBIS. Its a treasure trove of information particular for propulsion papers. One thing you could do is to join The British Interplanetary Society and ask for the journal as part of your annual subcription.
    You will then get an idea for whats being done today.

    The journal has been around since 1934 (although the BIS was formed in 1933). Interstellar studies in particular has always been one of its main areas and I would argue its the top journal in the world for these sorts of visionary papers. The good thing about JBIS, is that its open to submissions from anyone. Provided your paper is well written, nicely presented, tells a good story, covers a topic of interest to the readers (preferably some new insight but could be a review paper), contains the appropriate references and it is (most importantly) accurate, you have a good chance of getting the paper published. All papers have to go through the editorial peer review the same as any paper, but often we will work with an author to help them raise the standard of the paper before its accepted for publication. I say we, because I am the Assistant Editor, so should know.

    Look forward to your future submission and I hope you enjoy venturing into a subject of which you have clearly always had an interest, but want to take it to the next level. You will find we are a small community, but warm and helpful, all focussed on a specific set of goals, which includes both robotic and manned spaceflight.

    all the best
    Kelvin Long

  • Tim January 30, 2011, 5:21

    Thanks for the extended response Kelvin, I’ll certainly look into joining the BIS.

    I’ve done some very preliminary engine calcs for one of the GLXP teams, and I’ve read a few things around the place, so I guess I’m reasonably familiar with the challenges of conventional chemical propellant. I’ve also got a basic understanding of some of the more speculative approaches, but nowhere near a full engineers understanding. I’ve still got some reading to do.

    With regards to what area of propulsion I’m interested in, since it seems at this stage that no one approach allows carefree interstellar travel, I’m less interested in any one approach than in how several different approaches can be combined or made to fiit together to provide a better spaceship, say how a lightsail and an electric sail can be used together to maximise the acceleration that can be got out of the sun.

  • kelvin February 7, 2011, 20:16

    I like your thinking. Throwing all this technology together and is a good solution for an optimum performance mission.
    That’s what we are doing with Project Icarus, despite the perception that its just about fusion. We are looking at loads of different options for the early acceleration and deceleration phases.
    Obvious combinations for you to consider includes;
    nuclear electric
    solar electric
    fission fusion
    pellet stream fusion
    lots of more.
    Yes please join the BIS, we would welcome you warmly.

    Similarly, consider a JBIS submission, I would work with you to get the paper up to standard.
    All the best.