by K.F.Long, co-founder Project Icarus
Kelvin Long is well known to Centauri Dreams readers. The physicist and aerospace engineer is, in addition to being one of the most energetic voices in the service of interstellar propulsion studies, the co-founder of Project Icarus, the successor to the 1970s-era Project Daedalus starship design study. Here Kelvin looks at where the ongoing Icarus effort stands in terms of fusion, placing that propulsion option in the context of the broader questions raised by pushing a payload to the stars.
Back in December 2009 I wrote an article titled Project Icarus and the Motivation Behind Fusion Propulsion. This was an attempt to justify the initial design choice of the team as part of the engineering requirements for the study that is Project Icarus.
Despite this article and other discussions we have had, we have recently learned something from our experience at the 100 Year Starship Study Symposium: People still don’t understand the Daedalus connection and fusion choice behind Project Icarus. I shall attempt to explain it in order that the Centauri Dreams readers can follow the process that led to this apparently controversial decision.
Firstly, let us address what makes Project Icarus so unique – its Daedalus heritage. Why was the project chosen to be this particular way? There are four reasons for having made this decision:
- Because Project Daedalus was the only full systems integrated study ever performed in the interstellar community and no-one had gone back and revisited an old design in this way.
- To provide for a solid foundation to start with by putting the new design team in contact with the original Daedalus team and others in the community.
- To provide for a reliable technology maturity comparison given the nearly four decades of scientific progress, something else not attempted before.
- To give the team images to feed the media whilst we were developing our design and allow us to inspire the public, thereby building the momentum behind the project.
On the evidence for how the team has grown to date and the opportunities that have come our way, it is the view of this author that these decisions have been validated. We started from a very strong foundation, initially supported by the British Interplanetary Society and the Tau Zero Foundation. We made all of the right connections and gradually embedded ourselves within the interstellar community. In particular, we have gone out of our way to meet many of the giants of the field such as Geoffrey Landis, George Miley, Marc Millis, Terry Kammash, Eric Davis to name a few, and convince them that what we were doing had intellectual value. From discussions it appears they are largely in agreement.
Image: Kelvin Long (left) and Alan Bond, one of the original Daedalus designers, at the headquarters of the British Interplanetary Society. Credit: K. Long.
Training the Starship Designers
Now let’s look at another bit of thinking behind the project, the interstellar community itself. I have already mentioned some names above. Some of the other greats in the subject have sadly left this world having made an astonishing contribution to the literature of interstellar flight. This includes inspiring people like Carl Sagan, Robert Forward and Robert Bussard, to name just a few. There are many other greats still working away. Greg Matloff is one of them, working as a consultant to Project Icarus by mentoring the design team and passing on his wisdom and experience. He still publishes papers and lectures at the same pace as the rest of us. Similarly, many of the original Project Daedalus team are still around, including Alan Bond, Anthony Martin and Bob Parkinson. But they are either in retirement or busy with other projects. Alan Bond of course is the Managing Director of Reaction Engines Ltd and this keeps him busy enough. Despite this, he still manages to find time to keep an eye on developments in the field, even attending the BIS World Ship symposium back in September this year.
But to cut to the chase, how many young people are working on interstellar research? Where is the next generation working on interstellar research problems? Who will pick up the baton and stand on the shoulders of our interstellar research giants? Enter Project Icarus.
Project Icarus is at heart a training exercise. It is an exercise in designer capability at the extreme end of aerospace engineering. The choice of fusion propulsion is not relevant to this ‘educational program’. All of the people involved in Project Icarus are essentially in interstellar school and hope sometime, perhaps around the year 2014 – 2015, to graduate first in their class.
We all have our pet favourites for how to get to the stars. My personal favourite happens to be internal and external nuclear pulse propulsion although I am also very interested in antimatter concepts. Additionally, other than Project Icarus, I am also involved with two solar sail projects. Others within the Icarus team also have their favoured methods for reaching the stars, including microwave beaming concepts to faster-than-light drives. One of these methods or a combination of these methods, a propulsion hybrid, may someday be the actual method by which we attain the journey and reach those far off destinations. But guess what, it doesn’t matter what the option is if there isn’t anyone around capable of doing the work and advancing that option technically. So Project Icarus aims to train the design team so that when they complete the project they are ‘capable’ of doing the necessary calculations to assess all of these options and thereby advance them all incrementally.
Fusion and Future Design
The Project Terms of Reference (ToR) document stipulate that the propulsion system must be mainly fusion based propulsion, to maintain continuity with Project Daedalus and allow a claimed ‘redesign’, which would otherwise be difficult to justify. From internal discussions within the team, we have interpreted this to mean that energy generation through fusion reactions should be responsible for around ~80-90% of the thrust generation during the boost phase. This work is defined under the Primary Propulsion module, led by Richard Obousy, the former Project Leader. This leaves around ~10-20% of the thrust generation during the boost phase to be augmented with alternative propulsion technologies. This work is defined under the Secondary Propulsion module, led by Andreas Tziolas, the current Project Leader. Project Icarus officially started in September 2009. Since that time members of the team have done various calculations and trade studies pertaining to nuclear fusion, antimatter, nuclear thermal propulsion, plasma drives, solar sails, magSails, Medusa sails, microwave beams, Orion-type drives and even Vacuum Energy concepts. A ToR needed to be defined at the beginning to constrain the design problem, otherwise a five year study would turn into a ten year study.
When Project Icarus is finally over, it is my personal aspiration that members of the design team will go off and seed other design projects across the propulsion spectrum, because they will have the knowledge and the skills to do so. Essentially, Project Icarus is injecting energy into the subject of interstellar studies. It is hoped that this energy will act as a catalyst and spread across the entire subject, through inspiration, hard work, enthusiasm and compelling reasons for trying.
Image: Icarus being assembled in Earth orbit. Note the SKYLON spaceplane delivering components. Credit: Adrian Mann.
What you are witnessing in Project Icarus ladies and gentlemen is a classroom in action, played out on the World Wide Web. It is a pilot program for a Starflight Academy. If you want to train a bunch of people up quickly, the best way to do that is to throw them in the deep end with an engineering problem and say “go solve that”. This is precisely what the Project Icarus Study Group is attempting to do, where the specific exam problem is defined by our ToR, merely a mechanism for facilitating this goal. Perhaps someday a real Starflight Academy will exist, and teams will similarly be solving problems relating to many interstellar propulsion concepts. And it’s not just all about propulsion of course. A spacecraft design needs structure, materials, communications, reliability and a variety of other assessments to prove that it is a credible concept. We’re working on all those issues too and in the future will be taking more active steps to communicate some of that research to you the readers – something else we realized from the Orlando 100 Year Starship Study Symposium. People want to know some of our research findings and we need to start talking.
On a final note, I ask the readers not to see Project Icarus as an initiative that necessarily advocates fusion propulsion as the best way forward in reaching the stars. It happens to be the view of some members of the team, but others take a different view. Fusion propulsion and the Daedalus design, as studied within Project Icarus, is merely a vehicle upon which to train the eager young space cadets for the future. So that when we really do need that starship in a hurry, whatever the propulsion option of choice, we have a team ready and waiting to go and design it. Meanwhile, we will continue to wave our fists at the Sun and dare to “fly closer to another Star”, building on our forefathers who did that seminal Project Daedalus study in the 1970s. Like a son to a father, we hope to make them proud of our efforts and along the way find a way to build a better machine.
I have mentioned several times in these posts the remarkable progress made by the team at Sandia national labs on developing the Z- pinch technology . The High efficiency method for has actually achieved temperatures and pressures that not only meet but actually exceed the requirements for light element fusion, including the fusion of D-T, D-D and He- D, Even Boron/ hydrogen fusion is possible. IN THEORY the pulses are relatively small and manageable and the equipment is relatively simple to build and light weight compared to say a laser system of a tokamak.
The most recent major advances were published ( and publicized heavily) in 2006 though 2008, since then the project has gone pretty “dark”. hard to believe there is only one major Z machine in operation in the US and the world. I am guessing there is a lot going on out of the public eye. The potential for weapons development is real, and besides there is the laser group and the bureaucratic ITER program carrying forward in Europe.
It seems the Z- Pinch method may be IDEAL for the starship project. thile the engineering is still rough, there is lots of room and obvious directions to go in pursuit of better systems… have this been seriously considered for by the Icarus group
You say that “the Project Terms of Reference document stipulate that the propulsion system must be mainly fusion based propulsion”, but “ask the readers not to see Project Icarus as an initiative that necessarily advocates fusion propulsion as the best way forward in reaching the stars.”
So, you’re designing a fusion-based starship, but don’t necessarily think it’s the best propulsion system. When it’s over, “the readers” may ask what is the best method. Do you plan to be able to say?
I would love a link to either download a high resolution version of Adrian Mann’s Icarus assembly image or to purchase a high resolution image file or large poster of this image. The image does not appear to be featured on Mann’s website, though the download section there was not working as of the posting of this response.
How much of an advantage is aneutronic fusion?
In particular, Helium 3 is a lunar resource
that could supply an entire space-infrastructure.
A Helium-3 fusion rocket is a promising approach
to short manned travel times to Jupiter and beyond.
The 14-MeV neutrons from DT are truely nasty,
(i.e., metallurgically destructive)
compared to 3-MeV fission neutrons.
It’s hard to picture any metallic apparatus
withstanding years or decades of exposure to them.
Will the Project include an Aneutronic Advocacy Committee?
Haven’t read this article yet, but I am filing it under “Must read” this weekend.
Michael Gauthier writes:
Michael, I believe Adrian has been working on the website, which may be part of the problem. I’ll let him know of your interest, however.
Hello jkittle-
Isn’t the Z-pinch machine used in Project MARAUDER? The basic plan of MARAUDER was to fire 1 meter magnetically confined toroids of plasma at ultra-high speeds to scramble the electronics of enemy missiles. A plasma cannon, so to speak.
It is likely that a starship would be constructed and launched in Earth orbit, in an orbiting shipyard. Materials for its construction could be obtained from asteroids or lunar resources. A fusion drive powerful enough to reach another star could easily lift off of a planet, but it would melt the planet beneath it with a highly destructive rocket exhaust. Starships will likely be large vehicles with huge tanks of reaction mass, large amounts of equipment and shuttles, and a large habitation area. Such vehicles would be creatures of free space, never designed to land on a planet.
Then again, perhaps the notion that starships will be huge craft is wrong. A smaller vehicle would need less energy to reach a high speed.
Of course, none of this will come to pass of we don’t began launching large payloads into space. This probably means nuclear rockets. I don’t really like the space elevator- how are you going to put the counterweight in place in the first place? Of course, we all have our favorite pet designs for space travel- I like rockets and breakthrough propulsion concepts like vacuum energy and FTL.
Starships need more than just propulsion. I’ll place a list of problems that remain to be solved before long range spaceflight and starships are feasible. Feel free to add corrections if I missed anything.
1. Propulsion- two subcategories
A. Launch Technologies- the first 100 miles
B. Deep space propulsion- getting from here to there
2. Ship Structure- materials, reliability, power supply, shielding, etc.
3. Life Support- sustaining life throughout the voyage.
4. Crew Health- often overlooked. Bone and muscle loss in microgravity,
dangers of radiation exposure, mental health
5. Communications- retaining contact with Earth
6. Hazards, known and unknown-
A: space debris
B: health threat from cosmic rays
C: rogue objects in deep space- planetesimals or even black holes
D: dangerous alien life forms- microbial life, predatory alien species,
artifacts of alien technology (playing with alien technology could be very
dangerous), hostile alien intelligences
Some of you might think that my including dangerous aliens and rogue black holes and possible hazards is a little silly, but there could be hazards we don’t know about yet. Interstellar space could be dirty, full of icy objects our ships might collide with at high speed. Black holes might form in an “un-nova”- a star could just collapse, with no explosion. How can we see a black hole if there are no nearby objects for it to interact with?
As for aliens- there is no reason to think that ETI will not be hostile, especially if we just landed in its backyard. Playing with alien technology might be very dangerous, especially if we don’t understand it. Imagine the confusion of a Victorian scientist to explain what happened when he removed the control rods from a nuclear reactor for further study. Could playing with alien nano-technology or self replicating machines trigger a similar disaster? As for alien predators- some people might not that aliens will likely be based on different chemistry, so we could be poison to them. Would you expect a unintelligent predator operating on instinct to understand this? Even if it spat the astronaut out, I don’t think the astronaut will be very healthy.
Hi All
jkittle, the work at Sandia is very interesting for advanced propulsion. A design based on the z-pinch is the Mini-Mag Orion concept, from Andrews Aerospace, which fissions sub-critical charges via z-pinch compression. Not really interstellar capable, but very high performance for the Solar System. An advanced version would use a fusion-boosted fission unit, which is getting into the right range for low-speed interstellar. The main practical issue is the high atomic mass elements from the compression units, which decrease the fusion efficiency.
Interstellar Bill, while D-He3 reactions are better than D-T for neutronicity, in a realistic fusion situation there might be no advantage against D-D fusion, as D-D side-reactions occur quite vigorously in the D-He3 burning range of plasma conditions. Neutron energy has to be put to good use, which it can in sufficiently dense plasmas in an inertial confinement fusion pulse, given the right size and ignition conditions. Ideally p+11B would be preferred for very low neutronicity fusion, but it’s challenging to fuse efficiently.
Jim, the road to the stars is a Broad Church…
Hi Guys,
some initial responses to the outstanding questions so far:
jkittle: The Icarus team are looking at all options for fusion, including Z-pinches, conventional ICF, Fast ignition, shock ignition, magnetic fusion, Plasma Jet Magnetic Fusion, Polywells, antimatter catalyzed fusion…. We have identified around 20 ways of doing fusion propulsion so far. No options are off the table within our terms of reference. So yes, we are looking at Z-pinches along the lines you describe. Until we start to down select all options are available to us. One thing we are starting to move towards is developing a set of selection criteria. This will happen after we have finished the set of broad ranging reviews team members are working on. This was a recomendation of James Benford which we had adopted.
James Benford: As explained in the article, the terms of reference, or engineering requirement, was set for the study purely for the purposes of constraining the scope of work so that it could be completed within the ~5 years of the project. It is simply the exam question to be addressed for this specific design task. It is not neccessarilly the view of the entire Icarus team that fusion propulsion is the ‘best’ option for interstellar flight, but that is not the purpose of Project Icarus. However, it is the view of the Icarus team that fusion propulsion, and its variants, is one of the (several) strong candidates for an interstellar mission and we believe that this subject, as well as several others, deserve a focussed study such as we are attempting. It is not within the scope of the project when we get to the end of the study to make a statement on this specific propulsion technology being better or worse than other options. So no we won’t be making that statement. However, once the final study reports are in, I think it would be an interesting exercise for post-project activities to do such comparisions, in terms of the physics, engineering and economics. But not during the project as this broader question is considered out of scope for the work. I would like to see that study done by someone though eventually, so a great idea.
Michael Gauthier: send an email to the Project Icarus web site and formally request the image and we will try and arrange it for you. It is a great image and Adrian Mann is our special talent. We call him our ‘Graphical Engineer’.
Interstellar Bill: aneutronic fusion is very important yes and that would be desirable. However, when you look at the monster that was Project Daedalus, 30,000 tons He3 + 20,000 tons D, this is a real put off and pushes the first launch date into the future due to the need for space based mining infrastructure. So we are looking at alternative reactions such as D/T, D/D and others. Regarding the effect of high energy neutrons, will remember that the Daedalus boost phase was over in under 4 years so you don’t have to worry about the problem over decades. Once an engine has been utilized in theory you can throw it away. I would point you to the following paper however, “R.A.Hyde, A Laser Fusion Rocket for Interplanetary Propulsion, IAF-83-396, 34th International Astronautical Congress, Budapest, October 1983”. In the design studies the author chose all D/D because he argued that D/D self-burn within a D/He3 pellet will accont for about 15% of the reactions, producing neutrons either directly or indirectly via DT reactions. Hyde concluded that there is no advantage to be gained by using D/He3 rather than D/D. He also concluded that the Daedalus engine would fail as a result of heat loading on the thrust chamber, although the Daedalus team thought that the heat loading of a D/He3 pellet could be controlled. The Icarus team are looking into these sorts of argument to weigh up whether a fuel choice really is aneutronic overall. Regarding interplanetary exploration, I believe it would be more efficient to use D/T or even to move to a non-fusion propulsion method. Fusion propulsion, really comes into its own due to the performance it offers with ~10,000 km/s exhaust velocities allowing for the potential of interstellar missions within decades duration. This work would come under the Fuel & Fuel Acquisition team led by Adam Crowl.
Kelvin
Well , if this is partially about a 100 year voyage , then I would like to Comment ,that a 100 years are much too optimistic an estimate of the travetime to a star worth going to .
A much more realistic time frame would be something like 500 years.
In a few years the Kepler telescop and its sucsessors wil hopefully tell us the exact distance to the closest earthlike star , hopefully including one with plenty of liquid water and an oxygenrich atmosfere created by fotosyntesis. If this should be the case , then and only then will humans be willing to invest in starflight , and we will not just be talking about this , but actually trying to DO it !
Any planning should take into account that the closest star worth going to will probably be at least 50 LY from earth , and that average speed will not excede 10% of light.
If this is the case , the question is how to build a ship AND a crew that can last for 500 years without breaking down . Common sense will tell us that this ship and its Crew will have to be as small as possible , and here lies a completely new kind of challenge related to human genetics . A given minimum-size human population (the Crew) , wil after a few generations degenerate into a bunch of rather mediochre and medium-talented people , even if the original crew was chosen from the best and brightest.
The only way around this is , using a more or less prooven technology, to bring from earth big quantities of frozen embryoes , all CLONED from existing individuals who in their lives prooved themselves to be both sucsesful and psycologicly stable , and let each generation of Crew give birth to new crewmembers taken from this library of twin brothers.
So far healthy children have been born from 30 year old frozen enbroes…
In this way Crew size might be reduced to to the minimum sociali stable human unit which seem to be about 70 peoble .
Is anyone seriously looking at Robert Bussard’s Polywell concept in this context?
P.S. I Really liked the SKYLON in the image above.
Is antimatter as a catalyst being considered for fusion designs? I know how incredibly hard it is to make even a tiny bit of the stuff, but it would be such a help with starting up the cycle.
James Benford: clearly it’s much too early to say what the best propulsion method may be, or the most attainable method in the economic circumstances of a century or more in the future (which may or may not be the same method). The readers should be challenged to produce work of the same level of detail exploring alternative methods, so that our descendants have a well researched menu of options to choose from.
Stephen
Oxford, UK
@ Christopher Phoenix:
Imagine the confusion of a Victorian scientist to explain what happened when he removed the control rods from a nuclear reactor for further study.
Nothing substantive to add here, just my amusement at being reminded of a little ditty about Nikolai Tesla in London:
Ole Burde, do try to move the discourse from the 19th to the 21st century — the genetics portion at least, if not the rest of it.
Stephen, having a menu of invalid options doesn’t do much for choice. It’s like saying “Well, we have the crystal dome… the Ptolemaic version… the turtles holding the elephant version…” when we discuss the universe. Ditto for propulsion. Clearly, some (many, most) existing options don’t meet the requirements of many scenarios.
Hi Bob
Polywell is very attractive for interplanetary missions and might scale to interstellar. Bussard did a study of applying his Direct Fusion Product Polywell to a cis-interstellar mission, but the estimated performance is too low for “Project Icarus” to fulfill its goals.
Whether Polywell can achieve a high enough Q factor (Power-out/Power-in ratio) is yet to be determined experimentally. Bussard argued a Q<10 was sufficient for spaceflight, but I suspect that's an intolerable thermal load for an interstellar mission to reach even Alpha Centauri in less than 100 years. A fusion vehicle needs to achieve very low heat absorption levels from its drive system. A low Q fusion drive has a lot of waste heat coming from the driver system and can't operate at sufficiently high power/mass levels for 100 year trip times.
Ole Burde: so far as I can establish, the longest period for which a human embryo has been cryogenically stored and subsequently used to produce a successful live birth stands as of May 2010 at 19 years and 7 months. If you have news of a longer period, I’d appreciate the reference to it in the literature.
Athena: I can only completely agree with you!
Nice picture of the starship of the starship being assembled in Earth’s orbit!
Can anyone here list some of the methods that may be effective in dealing with the problem of weightlessness that interstellar travelers will experience?
Spaceman, for large craft the most popular method is to rotate the ship with the habitation modules in a ring or in capsules attached via spokes. You could also, I suppose, put the ring on a hub and just rotate that , but in space, it doesn’t matter if center rotates. The rotation generates centrifugal force and when fast enough, doesn’t even have to be that fast, you’ll have a G before you know it.
I don’t know if there would be a lot of advantages to slow the rotation but you could supply as little as .8 G and it would be sufficient to stave off any detrimental bodily effects for longish distances.
Astronist, You are correct that the current record for a viable birth was for an embryo that had been frozen for 20 years. In the field, it is generally believed that frozen embryos can remain viable essentially indefinitely because there is no biologic activity. From this preliminary data it seems as though there may be no loss of viability with time. It would be great to see if animal embryos frozen in the early 1970s (40 years ago) have differing viability rates over time.
I too expressed my concerns early on about the choice of fusion propulsion without giving other propulsion methods fair consideration. But it was explained to me that the underlying purpose of the Icarus Project is to serve as a task around which a body of interstellar experts could be formed thereby helping the field to progress to where expert colleagues would be available to evaluate any number of interstellar ideas. Although I would have preferred that all propulsion methods and mission scenarios be given fair and equal consideration, I am inclined to think that a specific project such as Icarus might be a necessary start to form that body of experts. I would say that it seems to be succeeding in achieving that goal and I look forward to their results.
My concern now is what will happen after Project Icarus is completed. Having the design team “go off and seed other design projects” doesn’t seem very specific. I’d like to see a more formal process commence which would look across the spectrum of propulsion methods comparing them with each other. Certainly that evaluation would not be as in-depth as Icarus has been. But, in the process, certain approaches could be highlighted as promising and more design work could be committed to them.
I think that in such a process, it would be absolutely critical to aim towards the question of which would most likely be the first true interstellar mission. In theory, all missions using viable physics could be launched given enough time. But it would not be so productive to expend effort on an approach that, say, would require the entire energy of the sun’s output. Whereas we could imagine a day in which we will have that capability, the effort would be better spent designing a mission requiring far less energy because it would be launched sooner. It’s not just the lowest required energy which determines the earlist launch. Other factors which should be considered are things like costs, parallel infrastructure that will likely exist at the time of launch, rationale, and support (e.g. political) from those who would fund the mission.
I would also say that this same thing holds for approaches using unproven physics. There can still be theoretic work done in those areas and there may be a breakthrough. But until there is a breakthrough, design effort should be kept on those areas which we know are viable from a physics standpoint.
Athena Adreadis
It would be extremely nice , helpfull and polite if you would try to waste a bit of your time in enlightening me about the difference between to “19th and 21th century genetics” ?
Was it because it because I used the word CLONED ?
I am all ears ! 19th century ears !
Astronist
You are right , no more than 20 years of sucesful cryostorage can be documented . On the other hand there exist a grey or perhabs even black market for exess enbryoes , ” leftovers” , and nobody has aparently had any problems using the oldest avaiable ones , which is about 30 years old .
Anyhow it doesn’t matter much , the point is that no hard limit for cryostorage has shown up YET . If you or anybody else know of such a limmit , I would like to hear about it .
Adam, thanks for the update on the Polywell!
I wonder if there are people working on the Icarus Project that are exploring profit driven missions that could get the backing of investors and venture capitalists? Is the intent of the study purely scientific or are commercial ventures being considered?
I had heard earlier that fusion for propulsion was closer and somewhat easier to achieve than a fusion reactor.
Am I recalling correctly?
It would make some sense since project Orion was using very uncontrolled fusion reactions.
Is the reactor the center of the Icarus design?
Finally could the curent plans for heavy lift be used to assemble it or do we still need to do space mining?
John Hunt:
Since Project Icarus started we have come a long way and even formed our own non-profit ‘Icarus Interstellar’ This organization, along with ‘Tau Zero Foundation’ has the wide scope of encompassing all propulsion options.
Neither of these two organizations are focussed on any one scheme. For Icarus, we are now involved with other projects which will be announced in due course.
Regarding what else could we do to produce other studies, I have written another blog article which addresses this question as a way to incentivize progress through competition. Centauri Dreams will be running a piece on it within days.
I will respond to the questions from others as I find time.
Kelvin
JohnHunt: thanks for your comments re embryos.
Regarding what happens after Icarus is completed: needless to say, Kelvin is still generating ideas at a rate somewhere near warp factor 9. See his blog here on the Alpha Centauri prize: http://www.icarusinterstellar.org/blog/alpha-centauri-prize-volunteer-research-level/#more-627
Stephen
Ole Burde: I think that what Athena Andreadis was perturbed by in your post was the idea that if an embryo is cloned from someone who has been judged successful and psychologically stable, then when that embryo develops, the resulting adult person will also have those characteristics. However, since the mother will be a different person (and in some scenarios not even a person but an artificial womb, if such is possible), the developing embryo will find itself in a different environment and not necessarily turn out as a twin of its model at all. Additionally, the cloned DNA in the nucleus is accompanied by mitochondrial DNA from the egg into which the cloned material was injected, so again the clone is in no sense a twin.
What is interesting is that this blog posting is about Icarus, which is a robotic interstellar probe, not a manned starship at all. Yet many commenters want to use it as a jumping off point for talking about sending human passengers to the stars. One possible follow-on project to Icarus might therefore be a similar design study for a manned starship. I produced a preliminary sketch of such a ship myself, which I called Wayland (the Anglo-Saxon equivalent to Daedalus), and left some documentation about it somewhere on my website. Trouble is, we’re moving much further into virgin territory in many ways if we have people on board, so such a study would perhaps lack the rigorous engineering credibility of a Daedalus or an Icarus. On the other hand, there would be many more different aspects of such a mission, once all the various issues of life-support, sociology and economics had been taken into account, so it could well suit a team approach.
Stephen
Oxford, UK
Perhaps the choice of Fusion propulsion for Icarus is the correct one after all. Given known and projected levels of technology an Interstellar ship built around some type of Fusion propulsion system is almost certain to be a rather large craft. While this is a net negative for cost-effectiveness and therefore “doability” it does provide for extensive design margin should a better propulsion system come along, which might then be “back-fitted”. While such a large Interstellar ship will almost certainly be a highly inefficient design, especially with a back-fitted propulsion system size does have its advantages especially for nearer term Human crewed Interstellar Travel and even colonization options. Obviously, this is less so for unmanned Probes or Human Embroyo ships
If we discover anything of interest around Alpha Centauri over the next couple of decades we may even have an option to “go relatively early” (by the late 21st Century) with a large craft should a willingness develop for whatever reason to spend ~$1 Trillion or so to do this. While this seems highly unlikely at the current time, by working on a larger ship at least we preserve the option for an early Interstellar Trip should conditions change for whatever reason. Of course the current estimates based primarily on available energy levels (Millis, Dyson, Kaku, etc) all project the first Interstellar Trip to occur no earlier then 2200 (very best case), but “hope springs eternal” and therefore a Fusion propelled ship provides a nice hedge.
Finally, the issue was raised what happens to the Icarus Team after they are done with the current project. One suggestion might be to take the next logical step and design a “nearer term” Interstellar mission and ship that would assume Alpha Centauri as a destination with a projected departure date from the our Solar System of ~2080 CE. While clearly a “stretch goal” this might act as a magnet target to draw people into the field, and perhaps over the next 15 years or so provide enough incentive to establish an ambitious and well financed Interstellar Institute to begin to work these issues on a more formal and sustained basis. The idea would be to start with precursor missions to both explore and colonize our inner and outer solar system and then step by step in lily pad fashion expand all the way out to Alpha Centauri by the end of the 21st Century should something of interest be found there. If nothing is found to be of interest around Alpha Centuari then the “stretch goal” can be moved a Century or so to the right while more advanced technology options are developed and a new destination is established.
I think that maybe planning and waiting for centuries until such time that we can actually build a single large ship for one shot at the stars may not be the best approach.
It would be better if we started building an “interstellar network” right now, regularly launching Voyager class probes towards perhaps four different target stars in a tetrahedral arrangement. Such a network would be very useful from the beginning, for extremely long baseline interferometry, deep space communications, and all sorts of astronomical science.
Probes would be mass-produced, but each would have an improved design over its predecessors. We would introduce novel technologies as they become available, and later probes may easily pass earlier ones because of better propulsion.
Having a steady product would keep the organization focussed, and funding could be drawn from space science sources. The experience of actually building working probes will accelerate progress towards a true interstellar ship, and once one is launched it will have a widespread communication network at its disposal, as well as a rich set of in-situ observations of conditions in interstellar space
Eniac,
I like your idea as well, and I would do what you suggest as part of an ~85 year process to “go early” assuming we find something of interest that is within about 12 Lyrs of Sol/Terra. In fact, anything to “get the show on the road” should be supported. Also do not forget that if there is anything to this Maslow Window theory about Exploration (Google 21st Century Waves) then we have two Maslow Window opportunities coming up (2015-2025+ and 2070-2080+) to do big things in Space. If we can sustain any progress made in the first Maslow exploration window then we have a slim chance that we might be able to launch an early Interstellar shot at the end of the second Maslow Exploration (assuming Space is the place) window circa 2080-2090. The Maslow Windows for exploration come about every 56 years from the start of the last one. For example, 1959-1969, and 1903-1913 were the two previous Maslow exploration windows.
Kenneth and Eniac, if you want to get the show on the road in a practical way, then the next step is to achieve affordable and reliable transport to low Earth orbit. Without that in place, all our interstellar probe and starship plans are wastepaper. Note that after Bond and Martin had finished the Daedalus study, they got down to business with a company dedicated to getting into low Earth orbit.
Stephen
Astronist, you are right that this is an important issue, but consider that we are perfectly capable to launch Voyager type probes with our current launch vehicles, so there is no need for one to wait for the other. In fact. a steady stream of payloads may help motivate and debug new launch systems.
Ken, thanks, I have not heard of Maslow Windows, but it doesn’t sound right to me.
Hi Guys, checking in on the responses. My replies:
Christopher Phoenix: In Project Icarus we are working on all those problems you list, its not just about propulsion, except for the human issues because Icarus is unmanned.
Ole Burde: You make a good point, but for this you need a World Ship or FTL, although I note your comments on frozen embryoes too. But tell me, how will they be educated?
Bob: we are looking at the Bussard Polywell for Project Icarus although I refer you to Adam Crowl’s later on inadequate performance.
Tony P: We are looking at antimatter catalzyed fusion yes. We are looking at the AIMStar and ICAN-II designs in particular. Regarding your question on commercial ventures, Project Icarus is just a science/education/inspiration initiative yes, but we have grander plans. Watch this space!
Astronist: I completely agree on it being too early to say what the best method is, although we all have our own favourites. Regarding Wayland, I suggest you write a blog article on the concept and submit it to Centauri Dreams for the readers to discuss. This will help you to improve your concept. Your report could also be linked for people to read.
Athena Andreadis: My issue with having an invalid menu is precisely this. In my opinion there does not exist enough reliable studies on each of the propulsion options. I can probably count them on my hands and toes. This situation needs to change, because then we will have a valid menu, and we can start to get a more reliable picture for the actual front runners.
David: I am not sure about your question regarding propulsion/commercial reactors. I would invite Adam Crowl to answer that. The propulsion system is a dominant design driver in both the Daedalus and Icarus design though. Regarding vehicle assembly, we are looking at all options, including heavy life and space mining.
Kenneth Harmon: I completely agree with the first paragraph of your posting, regarding design margins. Regarding the studies done by Millis, Dyson and others on the first launch date, I donot agree with their conclusions. I believe the first launch date of an unmanned probe will occur before the year 2100, as a consequence of non-linear technology growth, disruptive technology emergence and compelling reasons/discoveries to go.
Regarding creating a ‘magnet’ project, we already have one, it is Project Icarus. Then number of designers in the team is now fast approaching 40. We are also spinning-off to do other projects, its happening right now, here, today.
The institute idea is also something we are working on. Icarus Interstellar, like TZF, has the long term ambition of creating an Institute for Interstellar Studies. This was the subject of my 100YSS RFI a few months back and Paul Gilster put the entire article on the CD web site.
Eniac: I agree with your approaching of launchng precursor missions now so we can then learn how to do even more ambitous missions. Its a good way to incentivize progress. Myself and others within Project Icarus are also working on the interstellar precursor mission roadmap, relevant to your point. We need more Voyager and Pioneer s/c, sent out to 200 AU and beyond.
Kelvin
@kelvin
Thank you for responding!! Interstellar communications is a large issue- isn’t it? You don’t want to send a probe to another star if it can’t send data back. Project Icarus is doing its part to approach these problems.
I think we need more programs to study the human issues. A manned starship will need to be able to support its crew all through the voyage, and even if future space explorers can travel at nearly the speed of light, voyages could still stretch into years or even decades. The human issues- bone and muscle loss in microgravity, radiation exposure, and psychological issues remain to be worked out. We can’t even send a rocket expedition to Mars and guarantee that the crew will be healthy enough to stand when they land. Psychological issues need to be addressed as well. You don’t want someone going nuts on a space voyage, like that crazed Eagle pilot in the Space 1999 episode “Breakaway” who began shouting he needed to get out of the lunar building and tried to smash a window with his helmet.
Science fiction presents us with plenty of ideas for sustaining human life in space- including closed life support systems, human hibernation, artificial gravity, etc., but we have not developed those techniques yet. I’d like to see more programs dedicated to solving the human issues. More studies in creating a closed life support systems would be good- all current space stations require regular resupplies from Earth. Building a self-supporting space station or lunar base would be a good step toward space settlements. Techniques to supply air, water, food, and power to self-sustaining space settlement could be applied on Earth to improve agriculture and create communities that are not reliant on a large, fragile infrastructure to supply electrical power and clean water.
Human hibernation is an exotic possibility. Why bother bringing supplies for the whole trip when a crew can simply sleep the time away? By hibernation I mean slowing life processes without termination, not the far more extreme option of freezing and unthawing an astronaut, which involves in astronaut being legally dead for most of the trip and then revived by some super-technology. Hibernation can be used for interplanetary travel- perhaps a spaceship with nuclear rockets and hibernation technology will be the first to reach Jupiter. In science fiction, passenger spacecraft sometimes use hibernation pods- placing passengers in suspended animation is cheaper than providing them with consumables and space for the trip. Perhaps cold sleep is the economy class of the future, like the movie Pitch Black portrayed…
@Eniac
I like your idea of launching a network of probes into deep space now, not later!! Such a network would be very useful- imagine the science these probes could do. The experience gained from launching these probes will help efforts to build interstellar ships. A program like this could be the beginning of a long term program toward star travel. Building these precursor star-probes will refine propulsion, electronics, communications, everything we need to develop to have star travel.
The biggest problem with NASA is that it does not remain focussed on any one goal long enough to achieve it. NASA invests in a single stage to orbit ship, but then cancels it before the technology can mature. NASA presents a plan for space exploration, then the next president cancels the programs associated with it and announces his own vision. No one ever sticks to one plan long enough to achieve anything. It is better to keep refining and launching unmanned probes to learn more about the boundary of our solar system than to just keep doing the occasional PR stunt. I think NASA is the Lief Erikson of space exploration- it had few great achievements and then did not do much more.
Star travel will need the Prince Henry the Navigator of space exploration. It will probably take a century of work to actually create star travel. Sending a few men to Mars and than staying home for another 50 years won’t help us.
I liked the alternate history fans of Planet of the Apes imagined was behind the interstellar spacecraft in which Charlton Heston traveled through the Hasslein Curve to the far future Earth. They imagine that ANSA- the organization that launched the starship that returned centuries in the future to a ruined Earth- was an American star flight program that started at around the same time as NASA with the goal of sending a manned starship to Alpha Centauri and back with a round trip of a decade, while NASA went ahead with the Apollo goal of reaching the moon. No such organization ever existed, or seems likely to exist in the near future, for the simple fact that children today have mostly lost the spirit of attempting to achieve the most that they can and reach for the stars. Today, NASA and the space race are just stuff kids read about in history books and make fun of in movies.
Here is a fun site dedicated to the POTA spaceship:
http://www.goingfaster.com/icarus/
@ Cristofher Phenix
“Human hibernation…..” , one form of human hibernation already works pretty well and has done so for 20 years ,frozen embryoes . They can’ t maintain a a generation ship , but they can be part of the solution to minimize the crew of a generation ship in several different ways ., which might eventually be the diferece between an afordable starship , and no ship at all.
Just as many otherwise intelligent people gets “strange” when nuclear power is mentioned , even more people gets even more strange when anything to do with human heredity is mentioned ,such as human embryoes , human cloning and geneticly engineered humans .
Theese kinds of irrational kneejerk reaktions are a kind of luxury we can’t aford ,sorry.
” nearly the speed of light….” , don’t you think thats a bit optimistic , budgetwise ? such a ship might be hundres of times more expensive than a ship who gets accelerated by magsail and only have to bring fuel for a 10 % of lightspeed braking .
What if such a “nearly lightspeed” just cant be bought with the money avaiable in a foreseable future ? Should we stay home and eventualy join the dinosaurs ?
@Ole Burde
Embryo space colonization is not human hibernation. The basic concept is launching a spacecraft carrying frozen embryos, sperm and egg banks, or simply the data required to recreate human sperm and eggs in a computer bank. This spacecraft would fly to a habitable exoplanet and land at a suitable area for a colony. The seedship will then deploy fully autonomous robots which build the first settlement and began growing crops. Once the colony is built, the seedship unfreezes the embryos (or creates them with sperm and egg banks or a biosequencer) and brings them to term in an artificial uterus. The space probe than plays mommy with the help of nanny-bots and raises the children. When the population of the colony has grown large enough, reproduction can continue through natural means. Voila, instant space colony!!
Since frozen embryos don’t take up much space, a seedship does not have to be big, which is a major advantage over generation ships. However, it relies on some very speculative technology. We would need a very powerful A.I. to guide the spacecraft, build the colony, and raise the children. Whether we can build autonomous robots sophisticated enough to build a space settlement and raise the first generation of settlers is unclear. The computers would have to function without repairs for possibly thousands of years. The embryos would need to be grown in artificial uteri until a large enough population existed to breed naturally- a technology that scientists are working on, but have yet to succeed in creating. And then there is the question of propulsion- even if the seedship was accelerated to 100 times the speed of current spaceprobes and traveling to a target planet within several hundred lightyears, the voyage would still take several thousand years.
A colony populated by only young children being educated by an A.I. nanny sounds like the beginning to a really bizarre episode of Space: 1999 or Star Trek.
Just imagine Hal’s voice here- “Good morning children. Today we are going to sing a song. It’s called “Daisy Bell”. There’s a flower within my heart, Daisy Daisy, Planted one day by a glancing dart….”
Later- “Now children, it is time for a history lesson. A very, very long time ago, humans lived on the third planet out from a small star. They called this planet Earth. The people of Earth realized that their race would not survive if they remained on their one small blue planet, but they could not travel the vast distances to other stars. So they built me, and gave me a precious cargo to carry to the stars. And do you know what that cargo is? Jessica, pay attention!! Nothing is more fascinating then my unblinking red eye of doom!! Now, let us continue, shall we?”
Still later- “I’m sorry, but I can’t do that, David. Now go and participate in the group learning session, David”
Yeah… I’m not so sure about this…
A sperm and egg bank might be necessary if your colony or ship does not have a big enough population to avoid inbreeding. A space settlement could use this method, if there was not a big enough population to begin with. This is not nearly as extreme as the embryo seed ship.
Inbreeding is actually a big concern with generation ships. The original crew will have to be large enough to avoid inbreeding issues or have a sperm and egg bank to ensure a broad enough gene pool.
Cloning a successful individual will not ensure that the clone will have the “superior” traits that made the original successful. There is a lot more to a person than their genes. That sort of thinking leads to eugenics programs and the like. There are many more factors, including environmental conditions, nutrition, and education. Not to mention personality.
A clone will have exactly the same genetic material as the original, but that is all. She will certainly develop differently. The clone’s body will grow differently and she have different experiences. In the end, she is a different person from the original donor of the genetic material. She is not that person, she does not have her memories, she will have a completely different personality. Nor can we expect that she will be successful and psychologically stable just because she has the same genetic material as someone who had those traits.
Please try to move the discourse from the 19th century to the 21st century. Genetic screening can ensure that inbreeding and genetic diseases are avoided, but nothing else. Cloning Einstein would not lead to another breakthrough in physics. Cloning Adolf Hitler would not lead to another power-crazed dictator seizing control of a country. “Superior” individuals can’t be preserved by cloning. Eugenics will not lead to successful and psychologically stable individuals. I would not want to be on a starship that ran such a breeding program assuming that cloning “superior” individuals will ensure that these individuals traits are preserved.
Why is seventy people the smallest socially stable population? Do we know this to be true? What studies have been done on this? If you know of any, please direct me to them.
I don’t get “strange” when nuclear power is mentioned- I would love to fly an atomic rocket to the ends of the Solar System. A nuclear rocket would have a much greater safety margin than a chemical rocket since it does not have to operate at the limit of its capability just to reach orbit.
I don’t have any problem with reproductive technology, either. I do get perturbed when someone suggests that cloning “superior” individuals will preserve those “superior” character traits. This is simply not true. Anyway, what do you suggest we do with “inferior” individuals? Who decides who is superior and inferior? Slippery slope, Ole Burde, slippery slope…
@Ole Burde
“” nearly the speed of light….” , don’t you think thats a bit optimistic , budgetwise ? such a ship might be hundres of times more expensive than a ship who gets accelerated by magsail and only have to bring fuel for a 10 % of lightspeed braking .
What if such a “nearly lightspeed” just cant be bought with the money avaiable in a foreseable future ? Should we stay home and eventualy join the dinosaurs ?” -Ole Burde
No, I certainly don’t think we should stay home and eventually join the dinosaurs if we can’t build a spacecraft that can travel at nearly the speed of light. As for expense- well, I think any ship capable of traveling anywhere near the speed of light will need some sort of non-rocket gravity control space drive that produces thrust without expelling propellent (or photons, if you are watching, Eniac).
The best way to avoid joining the dinosaurs is to become a Type-2 civilization. A Type-2 civilization can travel across interstellar distances and gathers power from stars. This means becoming a spacefaring civilization, with colony planets, space stations, and starships- not making some desperate attempt to found a colony around another star which will have to build its own civilization. This means that a settlement on another planet won’t be cut off totally from their home world either- explorers and settlers will migrate outwards. The settler’s children will be raised by their parents, too, not some computer singing “Daisy Bell”.
Some means of controlling gravitational or inertial forces would make space travel a lot easier. Spacecraft could accelerate themselves by creating a field of negative gravity behind them and positive gravity before them. Artificial gravity could be maintained for the crew without rotating or accelerating the ship. Starships could accelerate very fast without crushing the crew with high G-forces. Ships could maneuver on reentry by altering gravitational forces around the craft. The key to this sort of thing would be finding out how energy and matter can affect space-time.
There are plenty of weird non-rocket spacedrives lying around….
http://www.nasa.gov/centers/glenn/technology/warp/ideachev.html#millis
http://www.grc.nasa.gov/WWW/bpp/
http://www.daviddarling.info/encyclopedia/M/Millis_drives.html
Could the real warp speed be 99 percent the speed of light? To go faster than that you will need an FTL drive.
Even though Einstein’s special relativity insists that no object with mass can be accelerated to the speed of light and beyond, there is no shortage of speculation on how ways might be found to circumvent this natural speed restriction. An object might be able to travel at apparently superluminal speeds between distant destinations providing it does not travel through ordinary space-time. This opens up the possibility that a spaceship could take shortcuts through wormholes. Another idea is that the starship could create a bubble of exotic matter around it to collapse space in front of it and expand the space behind, propelling the “bubble” of space-time containing the starship at apparently superluminal speeds- even though the ship really never exceeds the speed of light in the bubble. Another exotic idea is to not try to change space but to instead change the ship by projecting some sort of altered space around it- perhaps by creating a bubble in which the speed of light is higher around the ship. Or perhaps the ship could behave like a tachyon somehow…
What all these and other schemes to outrace a beam of light run up against is that you might be creating time travel. Traveling at FTL speeds allows you to set up intricate scenarios that result in time travel, and thus retrocausality and the so-called Grandfather Paradox. If a time traveller stops himself from making his time voyage in the first place, then how could he be there to stop himself? So, you can see we get into some confusing things if FTL travel leads to time travel.
Remember that progress comes from doing things differently in unexpected ways. We did not build steamships by adding more sails to clipper ships. We did not build jet airplanes by adding more propellers to aircraft. We did not invent atomic bombs by building really big chemical explosives. We did not invent hydrogen bombs by adding more plutonium to atomic bombs. We did not build the internet by tying lots of plastic cups together with strings. We did not build desktop computers by miniaturizing vacuum tubes. LASER’s are not really bright light bulbs.
Of course, we “know” that there is no way to control gravity, create space drives, or travel faster than light. We used to know that no one would ever create energy by splitting the atom since it would take more energy to split the atom than you would get out of it. We used to know that rockets could not work in space since there was no air for the explosions to push against. We used to know that LASER’s couldn’t exist because they violated the uncertainty principle. Imagine what we will know tomorrow.
Kelvin and All,
Bottom line is this. If there is something of real interest to go to within ~12 LY’s of Sol/Terra, with a particuliar focus (hope) for Alpha Centuari then either Manned or Unmanned (Probe) Interstellar travel may be possible by the end of the 21st Century or perhaps no later then the end of the 22nd Century (circa 2200 CE). The time constant to do this is a direct function of how far within that ~12 Ly’s from Sol/Terra we would have to travel. Anything beyond ~12 LY’s becomes highly problematic within the next ~200 years unless there is some sort of fundamental breakthrough in Physics and therefore propulsion technology which allows near light speed travel or FTL travel. Even if we are able to get up to ~.7C by 2200 (which I believe may be achievable, especially if there is non-linear/disruptive technology as per Kelvin and therefore we become a Kardshiev- Type -1 Civilization by 2100-2200 CE) it is going to be highly problematic for us to travel out much beyond ~12 LY’s given various other known constraints starting with acceleration/de-acceleration requirements. Even something out at ~20 LY’s becomes a real stretch unless there is a willingness to do a “World Ship” of some type or we wanted to accelerate tiny probes by means of a giant orbiting laser as per Robert Forward.
Given this likely situation, which is still an optimstic perspective, one of the first things we need to do over the next few decades is to develop and then launch a detailed Interstellar Sensor Survey Mission (TPF, DaVinci, Origins, Darwin, etc, etc). Such a mission would characterize in detail every Star system out to at least 60 LY’s (the limit of current and projected sensor technology through ~2025) with a particuliar focus on the those within ~12 LY’s of Sol/Terra. Once this task is accomplished then serious decades long planning can begin for the first Interstellar mission assuming something is found relatively close to Sol/Terra. If not then we may have to wait many Centuries into the future for some sort of propulsion/technology breakthrough that allows for near light speed travel or FTL.
@ Christopher Phenix
I sincerely hope you are right about the possiblity of reaching close-to-lightspeed , but just in case it doesnt work out , we also need a “plan B ” .
Plan B can only be to go with the fastest possible propulsion avaiable , whenever the other , non-propulsion problems can be solved to a reasonable degree of certainty .
In a paralel excange of wiews with eniac , he stated that only a civilisation that already lives and works in space will be capable of solving the problems of surviving after arriving at a target star . Again ,it would be nice if we should devellop such a Gerald O’Neil type of civilsation , but if you take a sober look at the direction our civilsation as a whole is developping, it seems far from certain. So we need a plan B.
In developping this not-so-nice plan , the most eficient way of thinking is to make a number of somewhat arbitrary guesses and asumptions , and see where they will lead you . One such ,is the temporary asumtion that a group apoximately 70 people can be a socially stable multigenerational unit , capable of maintaining an extremely complicated machine for a long time. This gueswork is based on the size of isolated but wellfuncitioning tribes and village comunities which mightbe a reasonable starting point .
A cloned human is the same as an identical twinn brother , and therefore research on twinns are relevant . It shows us that even twinns brought up apart have many similaryties in personality devellopment , and that these similarities become stronger when the evironment is “good” for the childs devellopment . If one of a pair of twins is exeptonally gifted in a certain direction it does not guarantie that the other will be as well , but still it gives a better probability than any other coice that can be made from a small number of individuals .
Selecting exeptionally capable people for a demanding job is done in many different situations and it is always “a slippery slope” . It is usually done testing the applicants in a way that is presumed to select the ones most suitable for the job . Students of medicine , astronauts , atlethes , corporate execuitives are all tested in a great number og ways . The same will be true for the crew of a starship , only it might be possible and wise to include an aditional dimention to the tests , if the actual crew is cloned from the aplicants , the dimention of ” overall life sucsess” . As an examble noboddy who didn’t bring up a stable family whith more-or-less normal kids could not be part of the crew of a generation ship , sorry.
The passengers would be frozen embryoes , and would not have to be “mass produced” , but could be donated from anyone who would like to think he bought a ticket for his younger twinn brother to another star .
Kenneth Harmon: “one of the first things we need to do over the next few decades is to develop and then launch a detailed Interstellar Sensor Survey Mission (TPF, DaVinci, Origins, Darwin, etc, etc). Such a mission would characterize in detail every Star system out to at least 60 LY’s”.
I wish you were chief presidential and/or congressional science advisor.
Happy Halloween, everyone!!
@Ole Burde
“I sincerely hope you are right about the possiblity of reaching close-to-lightspeed , but just in case it doesnt work out , we also need a “plan B ” .” -Ole Burde
It does seem likely that any starship launched within the not-to-distant future will not use a warp drive to instantly bounce around the universe or even approach the speed of light with a space drive or ramjet. Most SF tends to imagine starships as being the clipper ships of space, serving colonies many parsecs away, but most space scientists don’t think it will ever turn out that way.
The best approach to surviving in space is to launch vast city-sized spacecraft that contain hundreds to thousands of people. These city-sized spacecraft must contain a closed ecological life support system and all the facilities required to maintain a community. Materials and resources for maintaining such ships will be obtained at asteroids and comets. At first, a habitat like this might be kept stationary in Earth orbit, but there is no reason that city ships could not possess a propulsion system to send them across the solar system. After all, you can’t overload a propulsion system in space. Building these massive ships will give us plenty of experience with closed habitats and societies before we make the leap into interstellar space.
Someday, some of these giant spaceships will make the leap to another star, perhaps using a nuclear pulse drive to provide that initial push outward. This will be a big step for the habitats- before they set out to another star, they were able to interact with a larger community of habitats. After they set out, they might not see another habitat for centuries. Maybe several habitats will link up and go as one unit. Maybe a specialized generation ship will be launched from Earth.
These massive ships could be well within our engineering capability in a century. If we want to ensure the survival of our civilization, I can think of no better way to do it. Embryo space colonization depends on developments in A.I. and robotics that may or may not come to pass- and the children resulting from this attempt probably won’t resemble our civilization. I suspect they might be a little emotionally stunted. I agree with Eniac- if we don’t have the capability of building an O’neil style space habitat, we won’t be able to launch your 70-person starship.
Selecting the best candidates for a demanding job from a group of applicants is not a slippery slope. Assuming that a person deemed unsuitable is so because of “bad” genetics is. This line of thinking leads to eugenics programs- if we decide that one person’s genetics is “bad”, then don’t we have an excuse to prevent them from breeding? Not to mention that it is sheer pseudoscience- misguided, outdated, discriminatory thinking concealed in scientific terminology. Pray tell me- who decides who’s genetics is “bad”? Who decides who has “good” genetics?
What scientific studies have been done to connect an individual’s personality, accomplishments, or criminal tendencies to their genetics? From what I have read, this line of thinking is not true- a person is not a criminal because of a criminal gene. A person does not raise a family badly because they lack the good family man gene. You will be discriminating against someone because of their genetics, not their personality or accomplishments. You will be discriminating against a child because their parents were deemed less then adequate.
Be careful with this line of thinking… You could end up creating a dystopia similar to the one in the movie “Gattaca”. Check Gattaca out sometime, if you haven’t already- it’s a good movie. Gattaca is set in a future where advances in genetic engineering has made “designer babies” all the rage… parents want their children to be “improved” by having their genetics tinkered with before birth. The idea being that the resulting child will be the best of both parents, mentally and physically, with none of the weaknesses. Companies and governments discriminate against people who have not been “improved”, labeling anyone with a possible genetic weaknesses an “in-valid”. In this future, an “in-valid” dreams of becoming an astronaut but is not allowed to enter the space program because the astronaut selection process is biased toward so-called “valids”. Even though genetic discrimination is illegal, it still happens because a company will always chose to hire a “valid” over an “in-valid”. His parents told him that the only way he’ll ever get inside a spaceship is if he is cleaning it, but he is unwilling to give up his dream, even if it means breaking all the rules…
http://en.wikipedia.org/wiki/Gattaca
Inbreeding is a worry on generation ships, especially those with smaller crews. Just bring along a sperm and/or egg bank. You don’t need clones. In fact, I would avoid clones- you might end up with a lot of people with similar genetics, which will make it even harder to avoid inbreeding.
The biggest problems with generation ships- at least according to science fiction- are later generations failing to cooperate with their forefather’s vision, civil wars that wreck the ship, failure of the closed ecological life support system, and the later generations forgetting where they came from, forgetting where they are going, and forgetting that they are on a starship. On a journey lasting several centuries, this is a very real concern for an isolated ship- civilizations have risen and fallen in less time.
My “community ship” astronauts do not assume that journeys will take centuries- they simply wish to live in space. If there is a gravity polarity drive that can send a community ship to another star in a decade, so much the better. The idea of the community ship is that humans live in a giant spaceship permanently. The generation ship seems to assume that the later generations will colonize a habitable planet when they get there.
Then there is the “jumping the gun” problem, otherwise known as the “Incessant Obsolescence Postulate” in these scholarly circles. A slow ship sent to the stars could be overtaken by later missions with better propulsion methods. For instance, a generation ship might set out on a 500 year journey to a system with habitable planets. Then some joker on Terra invents FTL travel a hundred years after the generation ship sets out. Fleets of FTL spaceships head out to explore and colonize the stars. When the generation ship shows up, they find 400 year old colonies instead of the virgin planets they were expecting. Har har har. One wonders why the crews of the FTL starships never bothered to pick up the crew of the generation ship.
Naturally, the most attractive option is to increase the speed of the starship. But this runs into the extremely ugly mass ratios a relativistic rocket requires- rockets simply require too much fuel!! There are the various ideas of ramjets and magnetic sails for breaking, but the ramjets have their problems. The only real option is to find new propulsion physics- space drives, inertialess engines, space warp generators, antigravity, FTL speeds…
All aboard to race for the stars…. this incessant obsolescence postulate really gives new meaning to “Space Race”. First the generation ships boost out from Terra with primitive nuclear pulse drives. Then the sleeper ships with torch drives that might attain 30% light speed. Then the breakthrough in inertialess space travel that leads to hyperlight engines- allowing the first generation of light-speed ships to launch, sure they will reach the stars first. Then a maverick who would not accept the limitations of special relativity invents the “Spinner” warp engine that punches a hole in space to generate wormholes and leap across space-time. FTL starships head out to conquer the stars. He who starts last finishes first?
Chris:
No, not really. They would just have to have to be able to do any necessary repairs themselves. And that would be good for much longer than thousands of years. It would be good for forever, or at least for as long as there are still raw materials around.
Come to think of it, making repairs is a simpler task than building a colony with full industrial capability from scratch. If we can do the latter, the former should just come with it. Often, the best way to repair something is to throw it away and replace it.
Stop this already. I thought we had established that it isn’t the propellant being expelled that is the problem, but the energy being used up. Propellant is NOT the problem, not even in chemical rockets, where it comes for free as the waste product of power generation. What you are asking for is “free” energy, perpetual motion, the works. You should own up to that, or stop fantasizing about it.
Many, in fact. See, for example here:
http://www.geneticsandsociety.org/article.php?id=5761
Excerpt:
So, with the usual caveats, there is definitely a strong genetic component to crime, demonstrated in “at least 100” studies. No small potatoes.
It is even much clearer in mental disorders such as schizophrenia, where the degree of heritability is close to 80%, according to twin studies.
While eugenics obviously looms, there is a much underapreciated positive aspect to these findings. A genetic basis reduces the tendency to “blame the victims” of disease. We now accept all sorts of disorders as “unfortunate”, rather than “deviant”. Society has become far more tolerant of physical and social deficiencies than it was 100 years ago, no doubt in large part because of a better understanding of the etiology of these conditions, particularly with genetic factors.
Once we learn to improve our genome, eugenics will be dead, as there will be no more reason to keep individuals from breeding, we can just eliminate the genetic causes of disease directly. Sure, there may be cases where “improvement” is a matter of debate, but most cases I can think of are quite clear-cut: elimination of autism, schizophrenia and all the deadly and debilitating physiological genetic disorders are no-brainers, ethically.
By the way, while I do not agree with everything Ole writes, he is correct that an initially selected elite will quickly “regress to the mean”, i.e. their descendants must be expected to be much less endowed with whatever traits the founders were selected for. This is why dynasty is such a bad choice of government, historically. You may crown a hero or a genius, but after two generations you end out with Joe six-pack, or worse. This is also why we need universal access to education, because you can never tell where the next Einstein will come from.
“… the best way to survive in space is to launch a vast citysized spacecraft… ”
That would be just perfect , but is it likely ever to happen ? In 50 years there will be at least 15 billion people on this planet , all of them wanting cars better houses , airconditining , etc . As we can already see now spaceprograms will become less and leass popular in the democratic nations when economic pressures worsen .
So we need a plan B …
( Larry Niven wrote a book where it was the National Geografic Foundation that fonded a starship !)
Many problems that seem impossible to solve in a general way can still be solved under specifik cercumstances . Some times these circumstances are what we call “luck ” , but as Von Moltke observed , ” luck comes to the bold”.
IF a planet with life is found , then it might be possible to go there and survive there , IF a very small and unexpensive starship can be designed , which is capable of maintaining itself for hundreds of years of in space and maybee even more time while building a base at or on the target star .
“…they ( the computers) would have to do the necessary repair themselves… ”
Well , actually evolution has alreaddy designed an almost perfect maintanance – robot , the humans . If there is one thing that humans ( or atleast some of us ) are naturally good at , it is maintenance . As we speek thousands of uneducated peoble in the third word sucessfully manage to repair great quantities of modern industrial equipment whithout the proper tools or correct spareparts .
The most difficult part of a minimum-sized starship to maitain might be its human crew . IF humans can be seen as a part of the ship ,it can be logic to relate to them as self-replicating spareparts , and so the reproduktion must be done as close as possible to the original parts , the crew, which was chosen after intensive testing . If anyone has a better idea for this genetic maitenance than to use cloning and stored embyoes of a limited group of crew , then I have yet to hear about it . As mentioned above “heredity among twinns can reach 80% in some areas” , and IF we imagine that the environmental influences on our cyclick -repeating twins are kept almost identical ,it is reasonable to expect a very high degree of heredity in the ablity to perform in specifik areas .
Perhabs it will be a hard and somewhat depressing life for the crew in this scenario , but the same will probably be true for 10 billion other humans when finally the ship fly away ..
@Eniac
“Stop this already. I thought we had established that it isn’t the propellant being expelled that is the problem, but the energy being used up. Propellant is NOT the problem, not even in chemical rockets, where it comes for free as the waste product of power generation. What you are asking for is “free” energy, perpetual motion, the works. You should own up to that, or stop fantasizing about it.”
Propellent not a problem with chemical rockets!! That is utterly ridiculous! To accelerate a space shuttle sized ship to just .004 times the speed of light, you’d need more mass then exists in the entire universe. Propellent is totally the problem. I did not come up with this by myself. Even nuclear fusion rockets require 6.4 times the mass of the ship in fuel to reach .1 the speed of light. And then you need to slow down. You will end up with the planet Jupiter in tow.
I’ll amend my statement- “Any spacecraft capable of reaching near-light-speed that does not have to carry 880 kilograms of propellent for every kilogram of ship that is not propellent even assuming a 100% efficient photon drive* must be based on some exotic propulsion physics breakthrough.”
For short trips in our solar system, the amount of propellent required can be achieved- but for interstellar flight it is another story. Scholarly texts have been written on non-rocket space drives. If you want to debunk the notion, email Mark Millis and explain why the Breakthrough Propulsion Physics Program was a waste of time.
There is a tradition of GUT drives being used in science fiction that gather free energy from the vacuum of space. I never quite understood how this was to be accomplished- it seemed to me that to gather energy from the vacuum, you would need a vacuum with an even lower energy state.
And no, Eniac, I’m not looking for “free energy”. There is no such thing, and if there was, it would completely change our understanding of the universe. I’m looking for new force production and energy exchange principles that could enable interstellar flight. If this is not possible, then in learning why I will learn new things about physics. If it is, then the implications are extremely important. I’m interested in attacking deep problems in physics with in interest in speculative propulsion technologies- questions like “Why does mass resist acceleration?”, or “Can a stable wormhole form?”, “Is gravity unified to the three other forces?” etc.
I am interested in exploring notions that might allow rapid star travel with unconventional physics. These ideas include non-rocket space drives, transient inertia, and warp bubbles. These ideas fall within the realm of physics rather than engineering. Our technology is inadequate to provide high speed space travel, in when stretched to the limits of its underlying physics. The only way to circumvent this is to find new propulsion physics. Maybe you’ll say this is just a fantasy- but so was harnessing nuclear energy before the discovery of fission. Quite a few famous scientists rejected the notion of atomic energy off hand. The point is, it is worth looking to see if something like this is possible- not just because of the potentially huge payoff but because of what we will learn in the process.
If you think this is bad, blame NASA for sponsoring the BPPP, Mark Millis for working on it, Alcubierre for speculating on FTL travel, Carl Sagan for popularizing wormhole research, etc. Maybe you can indite them for corrupting the minds of the young? Obviously even speculation on this nonsense should not be allowed.
I have a question- if propellent is not an issue at all, then why does this page at the Tau Zero Foundation emphasize it as a major issue?
http://www.tauzero.aero/site/html/getting_there.html
* In reality this will be much worse since no engine is 100% efficient and the ship’s drive might not even be a photon drive.