The Icarus Challenge

Icarus faces many design challenges, one of which is communications. The Icarus starship will be conducting important measurements of the interstellar medium, and other long baseline measurements, which will necessitate a reliable communications link with Earth [1, 2]. Although communications are of primary importance, perhaps the most difficult design challenge are the propulsion systems.

Using Daedalus as an early baseline, we can estimate the D-He3 pulsed fusion engine requires around 50,000 tonnes of propellant [3]. On Daedalus, 6 fuel tanks were allocated to the first stage and 4 in the second. Each fuel tank was estimated to weigh in at 20 tonnes and so to maximize the total change in velocity (Δv), these tanks would be discarded as they were spent along the way [4].  The illustration by Nathan Fowkes, shown in figure 1, describes the Daedalus mission timeline.

Figure 1. Daedalus Mission profile, by Nathan Fowkes.

In the fifth icon as detailed in figure 2, the fuel tanks are discarded. In Daedalus the spent tanks are jettisoned along with the first stage engine. The second stage tanks are discarded after their fuel reserves are depleted.

Figure 2. Excerpt showing spent fuel tanks being discarded.

It is important to note the last 4 tanks on the second stage can be jettisoned years after the end of the acceleration phase. The 10 fuel tanks on Daedalus weigh 50,000 tonnes, thus the final 4 weigh 20,000 tonnes. When the tanks are depleted they weigh 20*4=80 tonnes. Thus the mass deficit is less than 1% (0.4%) giving us the option to delay ejecting them. Since they provide minimal drag in space and we not trying to accelerate their mass, there’s no intrinsic benefit to kicking them away earlier.

Fuel Tank Reuse Scenarios

So if we do take them along, what would we use them for? Let us explore some options:  

Option 1: Fuel Tanks as Communications Relays: This provides Icarus with a great opportunity – to use the spent fuel tanks as our communications relays along the acceleration path. The acceleration rate could be adjusted to fit a mission profile in which, fuel tank ejection timing fits coincides with the communication relay positions.

If we further correlate the pulsed fusion rate with the Icarus heat dispersion/power generation profile, we will arrive at a best case scenario for fuel tank re-purposing under this scheme. (Establishing the validity of this scenario would have to wait until the Icarus Main Engine is designed and thermally modeled – work planned for 2012.)  

Option 2: Fuel Tanks as Science Probes: Alternatively, the fuel tanks could be retrofitted as scientific stations for the exploration of the interstellar medium. A network of ejected drones could also be used as transmission lines for an interferometric gravitational wave detector, such as the proposed ESA/NASA LISA mission.

Option 3: Fuel Tanks as Drones: Seeing as the fuel tanks would have already been accelerated to velocities of some measurable fraction of the speed of light, they could be directed towards other interstellar targets of interest. With sufficient planning the drones can even be directed towards other target stars, on sub-missions geared for late encounters and mission times of a few hundreds of years.

The enormous 60 meter diameter fuel tanks could be covered in solar panels and be programmed to turn on automatically when they are within a certain solar flux. Gravity would provide some basic trajectory adjustments, pulling the drone towards their target star’s gravitational well. A charged laser communications pulse would signal back to Earth a summary of findings.

Given their size, the drones could be equipped with their own RTGs and be used for a wide variety of interstellar experiments, effectively combining Option 2 and Option 3.

Out of these options, the most advantageous to the Icarus primary mission is Option 1. Icarus’ main mission success outweighs the options for extending the main mission objectives.  We will also need to drop large communications relays anyway and so, since the fuel tanks will be dropped along the way, this scheme fits perfectly with the Icarus baseline mission.

Include the He3 Mining Balloon Storage Tanks

To make the fuel tanks capable of transforming into drones or relays, we would need to have some basic electronics package on each tank [5, 6, 7]. The tank interface with the Icarus could have this built in already. In fact, the electronics could be the same instrument package used for accumulating the fuel in the first place – part of the He3 mining instrument. The fuel will not need to be transferred from the fuel acquisition balloon tanks to the storage tanks onboard the Icarus – we just place them directly onto the spacecraft and consequently, reuse them again as transponders.

Therefore the Icarus fuel tanks are in fact “Transformers” with three phases:

Mining Balloon Storage Tank >

Fuel Tank >

Communications Transponder

Operational Outline

Under these assumptions, fuel tank geometry should be modified to fit in with our aspiring multi-use profile. The most restrictive design parameters are imposed by the communications relays. As such we propose the fuel tanks are constructed out of two parabolic dishes forming a clam-shell.

This would allow them to be used as effective communications dishes, to be deployed after separation from Icarus. One side of the ‘shell’ would face forward (towards Icarus) and the other towards Earth (or then next relay station). A small inertial wheel system for attitude control coupled with a Radioisotope Thermal Generator (RTG) for power, would allow two-way communications, as outlined in figure 3.

Figure 3. Parabolic clam-shell fuel tanks are deployed as communications relays. Note the fuel tank deployment is meant to be circular and out of the page.

We can now provide an outline of this fuel tank re-purposing scheme:

1. He3 Mining Tank Phase: The He3 mining balloons, will have some instrument package and basic thrusters. It’s essentially a large fuel tank which would be filled with He3, with some attitude thrusters and a balloon on top.
2. Icarus Fuel Tank Phase: Icarus would sweep around Jupiter (or Neptune) collecting these tanks and assemble them on its body, on the way out of the solar system *(Icarus builds his wax wings). The He3 refinery contains supply nozzles from its He3 scrubbers, which collect He and separate out He3. Those same nozzles now connects to the main fusion engine propellant supply.
3. Communications Relay Phase: According to our early mission baseline, the Icarus main engines are ignited outside of our solar system. The Icarus adjusts burn rate so that a fuel tank is depleted at positions where relays are needed. A fuel tank is dropped and is deployed, transforming into a relay.

Figure 4, depicts all three incarnations of the now multi-purposed fuel  tanks, which will primarily provide the necessary communications relays and redundancy for a successful mission.

Figure 4. The three incarnations of the Icarus fuel tanks.

Seeing how novel ideas are being introduced at remarkable rates during this study, it is certain that Project Icarus will have many surprises for us.

Project Icarus is manned by distinguished scientists donating their time and creativity to further the current state of the art in interstellar spacecraft design. If you have found this article to be of value then please consider donating a small amount to Project Icarus to assist us with our ambitions of creating a credible starship design.

Acknowledgements

I would like to thank the Icarus design team, for assisting in the development of this novel idea, amongst the many others.

References

[1] “PROJECT ICARUS: Relays”, P. Galea, Project Icarus internal research note (2010)

[2] “PROJECT ICARUS: Mechanisms for Enhancing the Stability of Gravitationally Lensed Interstellar Communications”, P. Galea, R. Swinney, 61st International Astronomical Congress, Prague, CZ (preprint) (2010)

[3] ”Project Daedalus: The Mission Profile”, A. Bond and A.R. Matrin, JBIS: Project Daedalus Final Report (1978)

[4] ”Project Daedalus: The Vehicle Configuration”, J. Strong and A. Bond, JBIS: Project Daedalus Final Report (1978)

[5] “Project Daedalus: Propellant Acquisition Techniques”, R.C. Parkinson, JBIS: Project Daedalus Final Report (1978)

[6] “NASA Stratospheric Balloons – Pioneers of Space Exploration and Research”, Report of the Scientific Ballooning Planning Team (2005)

[7] “Development of a Preliminary Technology Roadmap for Stratospheric Balloon Platforms Dedicated to Earth Science Applications”, Global Aerospace Corporation, prepared for the JPL/NASA (2002)

“Project Daedalus” was inspired by advances in nuclear fusion technology as well as the 1960s “Orion” nuclear pulse rocket. The apparently rapid developments in laser and electron beam initiation of fusion in the early 1970s caused many to believe that interstellar travel was now at least possible, no longer merely in principle, but using real near-term technology. Thirty years later nuclear fusion is edging closer to “break-even” – when sufficient energy is generated to power the triggering of the reaction, at least if energy conversion machines were in place – and the possibility of interstellar travel has become more tangible. “Project Icarus” carries the torch of “Daedalus” further forward.

Fusion will give us much more than interstellar travel, however. As the energy source of the Sun and the stars thus, indirectly of all life on Earth, fusion already has given us so much. Modern civilization became possible because of its use of chemical energy stored in the remains of living things once powered by the Sun, and in effect already uses (stored) fusion energy. While plenty of sunshine for our needs falls on planet Earth, it is spread very thinly and requires large areas to collect, and very large batteries or chemical fuels to store. Nuclear fusion can use the relatively abundant fuel of deuterium, found in any body of water in the Solar System, though some advocate rarer elements like boron and lithium, or even rarer isotopes like helium-3. Sufficient amounts of deuterium exist in the oceans to supply an energy-rich civilization on Earth for billions of years. With such abundant energy we could even mine the planet’s “rubbish” mountains for the resources we have discarded as “unusable” waste and begin reversing the damage wrought by 3 centuries of fossil-fuel powered industrial development.

High-performance fusion rockets would also open up the Solar System to speedy access via large space-vehicles, as well as enabling star-probes. Assuming a 1,000 ton space vehicle and constant acceleration at 0.722 m/s², which an exhaust velocity of 10,000 km/s with a mass-flow rate equal to “Daedalus’s” second-stage would produce, we get the following figures for travel times to various Solar System destinations.

Table 1. Travel Times for Mean, Minimum and Maximum distances. Mean distance is the difference between the mean orbital radii of the destination and Earth, minimum uses the distance of the destination at its perihelion and the maximum places the destination at its aphelion on the opposite side of the Sun to the Earth.

As can be easily seen even distant Eris, the former Tenth Planet, can be reached in a little over 3 months for just 960 tons propellant. The most difficult flight to Mars needs a mere 60 tons of propellant to deliver 500 tons of space-vehicle and its 500 ton payload. For comparison, the nuclear-propelled Integrated Manned Interplanetary Spacecraft (ref. Encyclopedia Astronautica), flying to Mars and back on 420 day missions were extensively studied in the 1960s. They typically required 1226 tons of materials in Earth orbit, used 873 tons propellant, and carried only 110 tons of payload, accommodating 6 crew persons. Since the shutdown of the NERVA program in the early 1970s nuclear rocket technology has essentially stagnated. More recent VASIMR plasma-rocket technology requires 476 tons of propellant to deliver 124 tons of space-vehicle in 39 days to Mars, while requiring 200 megawatts of power from a Magnetohydrodynamic generator fed by a gas-core reactor, itself a technology almost as difficult to achieve as the “Daedalus” fusion engine.

Another potential use for high-thrust, high-exhaust velocity fusion-rockets is the deflection and/or orbital management of comets and asteroids. Asteroids and comets more than 200 metres wide pose a long-term threat to human civilization, if not all life, on Earth. A fusion rocket using 100 tons of propellant and a 10,000 km/s exhaust velocity can produce a 0.1 km/s change in the orbital velocity of 200 metre wide asteroids that mass roughly 10 million tons. Even multi-billion ton asteroids, kilometres across, can be steered away from a planetary collision given a year or two of warning. Smaller asteroids can also be shepherded into more useful orbits and mined, their products returned to Earth-orbit via fusion rocket.

“Daedalus”, and its successor “Icarus”, extend our fusion-making abilities by requiring greater energy efficiencies and harder to achieve fusion reactions. Regular deuterium fusion, for example, produces ~40% of its energy as neutrons, which produces large amounts of heat. On Earth this is very useful and we have advanced steam-era technology for turning heat into power, but in space heat must be radiated away and this complicates the energy conversion process. “Daedalus” reduced the neutron heat-load by using the deuterium-helium3 reaction which produces far fewer neutrons and its end products are charged particles that can be steered via electromagnetic fields in useful directions. “Icarus” hopes to do the same, but with a clearer view of what such reactions require from our fusion technology. On Earth such low-neutron fusion-power would reduce the heat being ‘dumped’ to the environment and reduce safety concerns from neutron-activation of containment vessel structure, a source of low-level radioactivity.

The high-speed spaceflight enabled by high-efficiency, low-neutron fusion energy enables another desirable opening of possibilities – the mining of the gas-giants for helium-3. The interdependence of the two might seem a bottleneck, but there is a significant amount of helium-3 closer to Earth embedded in the crystal structure of the Moon’s regolith, deposited by the solar wind. As recently revealed the Moon’s regolith is also periodically coated by a thin layer of water, probably also produced by interaction with the solar wind. This may well provide a useful source of deuterium, thus allowing fusion rocket propellant to be extracted solely from the Moon, at least at first. The estimated helium-3 resource of the Moon is roughly 2.5 million tons, and the deuterium is probably similar. An estimated 4.1 million tons of fusion propellant as close as the Moon will be important in the early days of a developing solar economy. Long before we have disfigured the Moon we will have the means to mine the gas-giants, a resource many billions of times greater than the Moon’s.

“Project Daedalus” was the vanguard of practical fusion propulsion technology, and “Project Icarus” will carry us all closer to that goal. A goal that once achieved will give us far more than the stars, nothing less than security for our planet and access to many more as well. “Icarus” aims for the stars, but will lift up all of us with it as well.

If you have found this article to be of value then please consider donating a small amount to Project Icarus to assist us with our ambitions of creating a credible starship design.

Alternatively take a look around the remainder of the Icarus site.

There are many proposed schemes for interstellar travel. These range from experienced based chemical fuels to highly speculative proposals such as the space drive. So when Project Icarus was put together, why did the team settle on ‘mainly fusion based propulsion’ in the Terms of Reference for the study? It is useful to spend some time justifying the motivation behind this decision.

Firstly, it is necessary to understand some of the history of how Project Daedalus came about. It is generally accepted that the nuclear pulse propulsion scheme as proposed by Project Orion was demonstrated to work in principle. In other words, the Orion team produced a credible engineering design with most of the physics problems solved. What prevents something like Orion from becoming reality of course is the existence of several international treaties. In his autobiography ‘Disturbing the Universe’ the physicist Freeman Dyson clearly argues that today he does not support the propulsion scheme as proposed by Orion:  “Sometimes I am asked by friends who shared the joys and sorrows of Orion whether I would revise the project if by some miracle the necessary funds were suddenly to become available. My answer is an emphatic no…..By its very nature, the Orion ship is a filthy creature and leaves its radioactive mess behind it wherever it goes…..many things that were acceptable in 1958 are no longer acceptable today. My own standards have changed too. History has passed Orion by. There will be no going back.”

Other than Orion, there are several other propulsion systems which are potential candidates for the first missions to the stars. However, when one examines the potential performance and practicality of these different options objectively very few emerge as credible in the near term. This includes nuclear pulse propulsion and in particular either the continuous fusion or the pulsed fusion drive is desirable solutions. The pulsed fusion drive was used in the Daedalus design and uses a high intensity laser beam or electron driver to produce repeated detonation of fusion fuel pellets for thrust generation. The concept has been investigated thoroughly over the years from the work done on Project Orion through to extensive research on pulsed micro-explosions in the early 1970s. Hence, the physics of this type of propulsion scheme is understood sufficiently to enable confidence in any performance estimates for space applications. It is just the technology that is not yet mature.

An ideal requirement for a deep space propulsive engine is the use of lightweight but energetic (high yield per unit mass) fuels. The fusion reaction of hydrogen isotopes comes out on top. A fission rocket is also credible but produces mass-energy conversion with a lower efficiency than for fusion reactions, as well as producing substantial radioactive products. Similarly, antimatter rockets also offer potential with a much greater mass-energy conversion than fusion, but the reaction products are difficult to direct for thrust and the production and storage of large quantities of
antimatter is still a technical challenge. The ideal rocket would be a pure photon rocket.

Fusion propulsion (and the more generic nuclear pulse scheme) offers advantages in performance that far outweigh other propulsion schemes. This includes a range of T/W ratio where in particular a low T/W of around .0001 is possible with very high exhaust velocities of around 10,000 km/s. Also, low mass ratios with very high specific impulse of up to a million seconds appear credible. The use of D/He3 reactions would seem to be the most promising fuel although other fuels such as D/T have potential.  This sort of performance level would be required in order to reach any of the nearest stars within an approximately twelve light year radius in under a century. A fusion rocket which didn’t carry its own fuel would be even better and this has been proposed historically in the guise of the Bussard interstellar ramjet. The problem with this scheme however is achieving the fusion ignition of interstellar high flux ions or atomic hydrogen which has a smaller reaction cross section than hydrogen isotopes. Also, the drag of the spacecraft is proportional to the velocity, and a high velocity is required in order to collect sufficient matter using the magnetic scoop. Ensuring that the overall drag remains less than the thrust of the spacecraft is a technical challenge too.

Most space propulsion systems can be classed into two categories. The first is those that are power limited and although can produce a high specific impulse and high exhaust velocity it is at low thrust. Electric rockets come under this category. The second is those that are energy limited and although can produce a high thrust with high exhaust velocity it is at the cost of a short specific impulse. Both Chemical and nuclear rockets come under this category and this is mainly because the fuel will get burned too quickly. Fusion propulsion offers the advantages of both categories with good propellant utilization. The concept of a fusion based drive is not limited to theoretical studies.

Already an engine is in the process of being developed for Mars missions called the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) which is essentially a scaled down fusion demonstrator engine if improvements in the power, shielding and field control were made. This engine offers the potential for bridging the gap between high thrust-low specific impulse technology as used in conventional rockets and low thrust-high specific impulse technology as used in electric ion engines and it can function in either mode. Similarly, for a full-up pulsed fusion engine, the employment of different pellet sizes also allows a tailoring to the amount of thrust needed for each pulse cycle, with some of the emitted energy being bootstrapped to run the next cycle.

The physics of fusion research has moved forward dramatically in recent years with the US National Ignition Facility now operational and others such as Laser MegaJoule in France under construction. Fast ignition proposals such as HiPER are also under consideration. The chances for scientists finally solving the ‘fusion problem’ are greatly increased. With this in mind, thinking about the implications to a deep space missions is timely. It is quite possible that the demands of a fusion based drive will necessitate a sophisticated space based infrastructure for resource acquisition, processing, manufacture and construction. Especially if He3 mining of the gas giant Jupiter or even the Moon is considered. However, as a theoretical exercise in the application of science and engineering Project Icarus has a large amount of intrinsic worth.

There is another reason why fusion was chosen as the main propulsion engine. Daedalus was a historical design study that changed perceptions about what was possible with interstellar flight. When thinking about performing a design study for an interstellar craft, instead of starting from scratch with an unfocussed ‘anything goes’ design philosophy, it is arguably more useful to build upon the good work that has already been done, essentially standing on the shoulders of the previous generation of designers. Hence, a re-examination of Daedalus seemed an obvious way to go. This would allow a complete re-evaluation of the original assumptions as well as hopefully
improve the design.

Ultimately, the aim would be to improve the Technological Readiness Level for this sort of engine design type. If other teams used the same approach, and say built upon historical projects like Vista, Longshot, TAU or Starwisp it is a personal belief that the credibility of engineering designs for interstellar missions would be vastly improved. The historical link with both Orion and Daedalus also captured the hearts of the Icarus team and made for a strong support base upon which to galvanize both academic and public interest; a necessary condition to inspire people that this design study is worth doing. Although it is also true that after having questioned the original assumptions of Daedalus, the final Icarus design may look very different with technology not envisaged in the 1970s.

Of course, it is also worth pointing out that the Project Icarus Terms of Reference actually stipulate ‘mainly fusion based propulsion’. This allows for the potential for high gain enhancements such as by using Antimatter Catalyzed Fusion techniques. Similarly, the main engine can be supplemented by a secondary engine for part of the mission trajectory, such as by using a nuclear-electric engine.

It is generally the consensus within the interstellar community that the two strongest candidates for interstellar flight and which are a balance between performance and near term technology readiness is arguably solar sails and nuclear pulse propulsion. The large interest today in using solar sails for interstellar missions came about as a result of a publication in 1984 titled ‘World Ships: Concept, Cause, Cost, Constructions, and Colonization”, written by several members of the Daedalus Study Group who had spent many years studying fusion based propulsion. Thus demonstrating that the act of completing an interstellar design study opens up opportunities perhaps not before envisioned.

If designers concentrate on trying to advance these two schemes, solar sailing and nuclear pulse, the prospects for robotic missions to the Kuiper belt, Oort cloud and beyond will become ever more likely. Project Icarus hopes to contribute towards this end objective. It was the vision of Arthur C Clarke that humans should expand out into space as soon as possible, a necessary step for the continued survival and advancement of our species. Project Icarus is aimed at working towards this ultimate goal. So while from time to time we may have to justify to a sceptical public the motivations behind the assumptions of Project Icarus such as the choice of a fusion engine, the design team will remain focussed on achieving our objectives and continue to dream about the challenge of the spaceship.

If you have found this article to be of value then please consider donating a small amount to Project Icarus to assist us with our ambitions of creating a credible starship design.

Alternatively take a look around the remainder of the Icarus site.

When people read about The British Interplanetary Society Project Daedalus they usually marvel at the boldness of the idea and the amount of thought that went into the engineering calculations. Indeed, the major objective of Project Daedalus was to carry out a feasibility study for a simple interstellar mission but using only present day technology and with reasonable extrapolation to near future technology. However, it is not immediately apparent why Project Daedalus was undertaken in the first place.

One of the reasons was to investigate the Fermi Paradox first postulated by the Italian Physicist Enrico Fermi in the 1940s. This supposes that there has been plenty of time for intelligent civilizations to interact within our galaxy when one examines the age and number of stars, as well as the distances between them. Yet, the fact that extra-terrestrial intelligence has never been observed leads to a logical paradox where our observations are inconsistent with our theoretical expectation. This original question from Fermi seemed to also reinforce the prevailing paradigm at the time that interstellar travel was impossible.

Project Daedalus was a bold way to examine the Fermi Paradox head on and gave a partial answer – interstellar travel was possible. The basis of this belief was the demonstration of a credible engineering design just at the outset of the space age that could in theory, cross the interstellar distances. In the future scientific advancement would lead to a refined and more efficient design. The absence of alien visitors would therefore require a different explanation because Project Daedalus demonstrated that with current, and near future, technology, interstellar travel was feasible. Therefore, another solution to the absence of extra-terrestrial visitation was necessary. Although Project Daedalus was ostensibly focused on designing an interstellar flyby probe, the underlying motives were to frame discussions about the Fermi paradox.

In the years after Project Daedalus, a member of the Daedalus team Alan Bond plunged himself into researching biology to understand how species evolve from a single celled organism to something as complex as human beings. He argued that historically pure guess work had been used to determine the number of intelligent civilizations in our galaxy. The culmination of his research resulted in the publication of a paper ‘On the improbability of intelligent extraterrestrials‘ in 1982 in the Journal of the British Interplanetary Society. He concluded that organisms with the complexity of human beings may be rare and only occur with a probability below much less than once per galaxy.

This startling conclusion was based upon the development of a biological model assuming an observed exponential growth in the complexity of biological life in the fossil records over time. Bond had addressed the probability of Earth-like planets with Carbon based biology existing in our galaxy. Proteins, the complete set of genes which pass from a parent to an offspring, were seen as the fundamental mechanism of biochemistry on all worlds. The genome would increase in size over time and the establishment of intelligence would require a certain level of intelligence and therefore a minimum size of genome; the more complex an organism then the larger the genome required for its specification. Attainment of an intelligence level like us would take merely a few million years, for species which had a similar genome size.

Bond himself stated in the paper that a lot of assumptions had been made with inaccurately known parameters and that more work needed to be done. He said further that there was clear potential for an order of magnitude variation around the estimates that were derived. His actual numbers suggested that a planet with the development level of the Earth only occurs once in 50,000 galaxies.

He concluded that “whilst we are sufficiently rare to inhibit contact, at least with the Galaxy at its present age, we are not so rare as to defy phenomenological explanation”. The conclusions of this paper are a disappointment for those who believe intelligent life to be prolific. But it is interesting that in the Cosmos television series Carl Sagan also expresses the view that although life may occur purely as a function of chemistry and on most worlds where the environment is suitable, intelligent life in complex beings like us may be rare. When two great thinkers share a similar vision this requires contemplation. The rare intelligence hypothesis paints a very different picture of intelligent life in the universe to that of shows like Star Trek.

As a literature search on the internet shows, there are many potential answers to the Fermi Paradox and it may remain unresolved for some time. Although, advances in observational techniques for looking at distant extra-solar planets may lead us to an answer sooner than we think. One thing is for certain though, the contribution of Project Daedalus to the debate was first rate, demonstrating the possibility of star travel and forcing us to consider other more profound answers. It was no surprise that Alan Bond would also be one of the pioneers in searching for alternative explanations. There is one way we will know for sure, and that it to build something like Daedalus or Icarus in the coming decades, and then go see for ourselves.

If you have found this article to be of value then please consider donating a small amount to Project Icarus to assist us with our ambitions of creating a credible starship design.

Alternatively take a look around the remainder of the Icarus site.

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Project Icarus a Starship for the 21st Century

Project Daedalus, a Nuclear Starship

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The potential of nuclear power as a propulsion mechanism that would allow for interstellar flight has been recognized since the first half of the 20^th century. The idea was initially proposed by Stanislaw Ulam at Los Alamos in 1947 and then, in 1958, Ted Taylor initiated Project Orion.

The idea behind Project Orion is to detonate a nuclear charge at some distance from a vehicle. The detonation creates an expanding plasma wave which transfers momentum to the vehicle by hitting a pusher plate. This detonation process is repeated, and the rocket achieves thrust. In 1965, the Test Ban Treaty, which prohibits the detonation of nuclear devices in space, put a stop on the development of the nuclear pulse rocket.

Several years later, Alan Bond of the British Interplanetary Society, believed that the time was right to investigate the feasibility of an interstellar mission. He discussed the idea with members of the Society and Project Daedalus was born.

Project Daedalus began on 10^th January 1973 and the final reports were published 15^th May 1978 taking just over 64 months or over 5 years. Approximately  10,000 man hours were used by 13 core designers and several additional consultants.

In essence, Project Daedalus was a feasibility study for an interstellar mission, using 1970’s capabilities and credible extrapolations for near-future technology. One of the major objectives was to establish whether interstellar flight could be realized within established science and technology.

The conclusion of the report was that Interstellar flight is feasible.

If you have found this article to be of value then please consider donating a small amount to Project Icarus to assist us with our ambitions of creating a credible starship design.

Alternatively take a look around the remainder of the Icarus site.

Useful Links

Visit the Project Icarus website

Interstellar Propulsion and the Fermi Paradox

Project Icarus, a Nuclear Starship

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Welcome to the Icarus blog. On this page, members of the Icarus team will post their thoughts and ideas while being able to interact with visitors to the site.

To contact the Icarus team write to: info@icarusinterstellar.org