2005-01-3413 A New Approach for Single Stage Ascent to Orbit Silane Fuel in a New Vehicle Design David Padanyi-Gulyas and Andras D. Bodo Nitronics Aerospace Technologies, LLC Copyright © 2005 SAE International ABSTRACT MAIN SECTION Spacecraft designs incorporating a propulsion system powered by a more efficient fuel would greatly reduce the oxidizer to payload ratio. This could be accomplished with a single-stage vehicle that uses air while in the atmosphere and switches to onboard oxidizer only after reaching the upper limit of the atmosphere. In this presentation, a revolutionary new vehicle is proposed that incorporates silane-based fuels into an air-breathing spacecraft design that achieves orbit via low ascent angles, where it then switches to onboard oxidizer. A ceramic and alloy propulsion system takes advantage of the properties of silane, utilizing both the oxygen and the 80% nitrogen of the atmosphere for combustion. LOW-ANGLE LAUNCHING APPROACHES, BACKGROUND INTRODUCTION Using a revolutionary new engine design is the basis of the vehicle proposed in this presentation: in contrast to jet engines, this innovative new turbine-less engine design uses intelligent pressure management for nitrogen combustion to produce the energy for achieving speeds past 9,000 mph. To use this new propulsion system and achieve these speeds in the atmosphere, the aerodynamic design of the vehicle mimics the wing of a supersonic jet in all of its cross-sections. This rotation-symmetric, disk-like design addresses the air with a knife-edge silhouette that minimizes friction and heat produced by these speeds. Increasing speed of the vehicle makes up for decreasing density of the air until it reaches escape velocity at the edge of the atmosphere. While reentering the atmosphere, the compact and robust shape of the discus and the outer rotating protection ring, made of silicone nitride and silicone carbide, distributes the kinetic energy and the heat to allow slowing to speeds seen in normal jet aircraft. By then, after opening the protecting covers, a wreath of counter-rotating internal blades are used to touch down vertically; the same way, lift-up is accomplished. In another presentation at this conference we will learn of the exciting capabilities and advantages of silane fuels that can be used in this innovative spacecraft design. Our traditional, vertically launching, three-stage space carrier systems, all based on the well known rocket equations, represent a highly inefficient fuel to payload ratio, partly because of the necessity of carrying fuel AND oxidizer all their way along. Refueled, the three stages make up about 97 per cent of the entire take-off weight. In the case of the moon rocket Saturn V, this amounted to nearly 3,000 tons! Each time the fuel content of one stage is consumed, it is disposed of and the next stage takes over for further acceleration. The disposed ballast, as part of the most modern technology of mankind, burns up in the terrestrial atmosphere. Nevertheless, this was the method for the greatest triumph in the history of manned space travel. In view of this success, the exorbitant cost involved, especially in cold war competition, was rather minor. But even then, serious research efforts were made to replace this expensive habit of disposal by reusable systems. Quite early, then, in the sixties of the last century, Eugene Saenger and his assistants proposed a completely reusable spacecraft: using the aerodynamic air lift like an airplane, his two-stage system would lift off horizontally, thus overcoming the rocket equation. This way, the engines did not have to carry the entire weight of the missile but ensure only horizontal acceleration (Fig. 1). Fig. 1 The intention was to accelerate the delta-shaped carrier up to a speed of approximately 3,700 mph. Then, at the altitude of about 20 miles, the strapped-on rocket plane would be separated and produce the necessary speed to reach orbit on its own (Fig. 2). Fig. 4 Fig. 2 A propulsion system with an innovative jet drive that would use air instead of oxidizer for combustion so that an enormous weight reduction would be possible was proposed also: ramjet propulsion. Different from ordinary airplane turbines, this drive has no rotating parts and theoretically allows a multiple of the speed of sound. Liquid hydrogen and the roughly 20% oxygen portion of the air would create the combustion. The forward propulsion of the flying object itself would provide the air compression necessary for efficient oxidation (Fig. 3). Fig. 3 However, the ramjet develops pressures high enough for combustion only at speeds over Mach 3. For lower speeds of launching and landing, a turbine had to be integrated. Complex mechanisms to reroute the air stream should enable the switching between the two drives (Fig. 4). The development of a reliable technology for this highly complex apparatus was finally estimated as too timeconsuming and risky by NASA - the space shuttle was built instead. The carrier plane was simply replaced by the reliable rocket technology. Since the space shuttle system - still launching vertically - relies on the rocket equation again, both fuel and oxidizer have to be carried along and the empty fuel tank has to be discarded, just as before. The two booster rockets are separated within the atmosphere and fall back into the sea slowed down by parachutes. Their propagated reusability is questionable, however, after the tragic incident, when refurbished boosters caused an explosion. Nowadays the only part reused is the orbiter itself, which soars back to earth after the mission. Much effort is needed, however, before the space shuttle can be launched again, for transport back to the lift-off area and for extremely thorough inspection. The numerous ceramic tiles, which are glued or screwed on, need extra special attention since they have to protect the vehicle against the inferno of re-entry. This way it takes months for general overhaul before the space shuttle is ready for take-off once more. The total costs for launching this two and a half thousand ton construction exceeds even the costs of conventional rockets, which burn up totally. But the price we pay for these achievements is not only monetary: the ozone layer of our planet is considerably injured each time the booster rockets of the space shuttle burn their fuel. That sounds relatively harmless in comparison to the high risk of the carcinogenic fuels used in the European Ariane carrier rockets. It has become an urgent matter to come up with appropriate solutions. Again, Saenger’s concept with its horizontal launch is being discussed as one of the most favored. This type of space flight seems to be an elegant alternative; however, the system‘s most critical aspect is the air-breathing ramjet, which appears to turn out unsuccessful because of one important aspect: Hydrogen is the ideal fuel for the air-breathing ramjet. It reacts with the 20% oxygen of the air to build water steam. The major part of the atmospheric gas is nitrogen (80%) with its characteristic of a mutual triple bond, which is why it doesn’t participate in chemical reactions. This is significant, because normally a triple bond in a chemical compound is highly reactive. Because nitrogen is heated along with all other parts of the atmospheric gases without reacting, it is the cause for the diminishing efficiency of the engines. Furthermore hydrogen uses up a multiple of volume compared to other fuels, which drastically affects size and thus weight of the entire missile carrying the fuel. And to top it off, hydrogen’s boiling point is as low as -252° C and can only be kept at this extremely low temperature with an enormous effort. The geometry of suitable fuel containers is difficult to match with the shape of the carrier aircraft. However, there is also the orbiter, which is disconnected at an altitude of 20 miles. For its atmospheric traveling part, it should be long and pointed. This geometry is the opposite of what it should be during the re-entry phase, when a compact plump shape is favorable because it needs to withstand enormous thermal and mechanical strain. The compromise of the two geometries would look not much different than the space shuttle. Such a plump and heavy construction causes immense resistance and is the cause for inefficient supersonic performance. The greatest disadvantage results from the shape or rather the way aircrafts are constructed: the rib frame technique from ship building, forming a light and flexible shell (Fig. 5). chamber, will burn with the 80% nitrogen part of the atmosphere. This was discovered and patented in 1994 at the University of Cologn by Dr. Peter Plichta. Air-breathing rocket drives using not only oxygen for combustion but also its 80% nitrogen component will initiate a new era of propulsion systems (Fig 6). Fig. 6 The nitrogen utilization turns combustion kinetics upside down because it has the characteristics of an implosion. This revolutionary combustion method needs a newly conceived ceramic engine, which could be trend-setting for future jet engines. In contrast to common jet drives, this innovative design together with a new construction method eliminates rotating elements such as turbine wheels, regardless of the craft’s speed. Clever management of the pressure automatically supplies the drive with the amount of air necessary for oxidation, which is uniquely possible because of the nitrogen combustion (Figs. 7 and 8). Fig. 5 This flexible wing construction is a great disadvantage during the stresses of re-entry. The utmost consequence would be complete failure, when minor twisting forces would destroy the protective ceramic layer and would expose the vehicle to extreme conditions. That is why the ceramic protection shield must consist of many small tiles to better compensate for vibrations and shearing forces. Such a construction in re-entry is strained to the limit and a failure like that of Columbia could happen. Fig. 7 AIR-BREATHING PROPULSION ENGINE, USING SILANE All those problems of space flight make us aware of the fact that of the current technology has reached its limitations. Refinement and further development would increase expenses while there is no guarantee for more reliability or profitability. The only way out of this technical dead end is to reform space flight totally. One condition was the discovery of a new fuel called silane. The chemical and thermodynamic characteristics of silanes will be introduced in another presentation at this conference. Only the most important characteristic of the silanes has to be emphasized here: their silicon atoms, in a hot combustion Fig. 8 This highly efficient air-breathing drive enables the space craft to accelerate past 9,000 mph within the atmosphere. Before, such speed was possible only with conventional missile drives, which had to lift and accelerate the extra weight of the oxidizer as well. For reasons of patent protection, more details cannot be disclosed. blades at the perimeter stabilize the vehicle horizontally using the principles of precession (Figs. 11 and 12). A NEW DESIGN FOR A COMPACT, SINGLE-STAGE SPACECRAFT To move through atmospheric gas at such a high speed, the shape of the aircraft needs to have excellent aerodynamic performance. The outline chosen is similar to that of a wing profile of a supersonic jet, which literally cuts through the air. This profile is rotated around a vertical axis, providing each cross-section of the body with a supersonic geometry. Fig. 11 The result is a new propulsion concept combined with an extremely compact missile, which cannot be compared any more with any conventional flight apparatuses of any type (Figs. 9 and 10). Fig. 12 Fig. 9 To reach orbit, simple horizontal acceleration is required. At a speed of approximately 200 mph, the cover of the rotors is closed and the vehicle is propelled horizontally by the air-breathing engines. Beneath the covers, the rotors continue to move with flat blades to further stabilize horizontally, while the air craft continuously accelerates and rises. The rotating outer rings of the discus also distribute thermal stress, generated at the air-vehicle interface to minimize the heat at the leading edge as speed increases (Figs. 13 and 14). Fig. 10 Like a helicopter, it can lift off vertically: the uplift is created by counter-rotating adjustable internal rotor blades at the perimeter of the vehicle. This provides for incredible maneuverability that, combined with the completely symmetrical discus design, is aerodynamic in any direction. In addition, the counter-rotating rotor Fig. 13 To guarantee continuous efficiency of the jet drive, the force of the increasing speed compensates for decreasing air pressure. After slowing to below sonic speed, with re-opened covers, the rotating internal blades are used to touch down vertically. After a short safety check, the discus can be refuelled and reloaded for the next mission. The costly general overhaul, such as needed by the shuttle, is usually not necessary. Fig. 14 Therefore, up to an altitude of 30 miles, sufficient air will be pressed into the drive and the air-breathing engines will accelerate up to Mach 15. As the discus approaches the escape velocity of earth's gravity, in the thin atmosphere at that altitude, the engines can be powered by a small amount of onboard oxidizer to achieve the added speed necessary for orbit. To return to earth, the shape of the discus and the outer rotating ring made of silicone nitride and silicone carbide distributes the kinetic energy and the heat of reentry to allow slowing to speeds seen in normal jet aircraft. The shape of the discus correlates optimally to the requirements of re-entry. It is compact and extremely resistant to shearing forces. This is supported by the innovative construction without framework or tiles. The high tech construction materials used are porous, very strong, with perfect thermal and sonic isolation properties, and are very lightweight: they float in water. The clever composition of metal and ceramic foams allows a layer-like outer shell that is assembled like a sandwich, and it protects the interior effectively against heat, radiation, and mechanical impacts (Fig. 15). Fig. 16 CONCLUSION FURTHER USES Experts predict a high demand for high speed airplanes, especially for passenger flights now that the only supersonic commercial plane of the world, the Concorde, has been discarded because of its age. This revolutionary and innovative concept will also be used to design vehicles that fly at incredible altitudes. Via the airbreathing jet drive accelerated to eight times sonic speed, it would then glide on the air like a flat stone on water and carry passengers from New York to Beijing in only 2-3 hours. PERSPECTIVES In the process of the discus development, a technically detailed computer model is being developed, electronic data from which is to be used for the first remote control functional prototype with a diameter of 150cm. This model is supposed to convey the unique maneuverability. Simultaneously, different production and material technologies are to be tested and optimized that finally will lead to a full-size affordable aircraft. Fig. 15 The rotating outer ring distributes the friction heat during the process of re-entry (Fig. 16). Step by step upward scaling is to result in a functional prototype. Within a few scaling steps and a few years, a prototype with a diameter of 20m for space flight could be completed, which could even carry freight into orbit. The final size, to bring up to 100 passengers into space and back, would be of far greater diameter. ACKNOWLEDGMENTS The authors want to thank hereby in general all persons and institutions involved in the preparation of this presentation for their valuable and highly appreciated support: David Zornes invitation to SAE WAC, Peter Plichta, Erika Kirgis, Franz Willi, and Linda Bell Carlson. CONTACT Nitronics Aerospace Technologies, LLC 3116 S.W. 153rd Drive Beaverton, Oregon 97006 REFERENCES ̇ ̇ ̇ Benzin Aus Sand / Die Silan-Revolution (Fuel, made of Sand / The Silane-Revolution) by Peter Plichta, Langen-Müller Press, 2001 NET-Journal (Switzerland) Vol. 7/2002, pg 4ff Raum&Zeit (Germany) Vol. 115/2002, pg.74ff 

2005-01-3412 Silicon Based Fuels for Space Flight David Padanyi-Gulyas and Andras D. Bodo Nitronics Aerospace Technologies, LLC Copyright © 2005 SAE International ABSTRACT Limiting factors in air and space propulsion systems affect both design and operation of the engines and the energy derived from a fuel source. Translation of the fuel source to energy (combustion) always requires an oxidizer. The process of breaking the energy-laden bonds of the fuel has classically been achieved using the oxygen in air for air-breathing engines or an onboard source of oxidizer for spaceflight. This is a critical limitation for a possible single-stage vehicle, because the weight of the fuel and oxidizer needed to achieve the necessary speed and altitude for orbit is excessive. This problem was overcome using multi-stage engines that are discarded sequentially during vertical ascent. However, the relative inefficiency of fuels currently available perpetuates the requirement for multi-stage engines to achieve orbit. Multi-stage rockets still require onboard fuel and oxidizer at lift-off that can account for over 95% of the lift-off weight. Only with more efficient fuels and propulsion systems will it become possible to achieve orbit and spaceflight without this limitation. More effective spacecraft designs incorporating a propulsion system powered by a more efficient fuel would greatly reduce the oxidizer to payload ratio. This could be accomplished with a vehicle that uses air while in the atmosphere and switches to onboard oxidizer only after reaching the upper limit of the atmosphere. This more efficient fuel is now available. The use of silanes (silicone hydrites) provides the fuel necessary to achieve this radically different and efficient means of propulsion, using both the oxygen and the 80% nitrogen of our atmosphere for combustion. INTRODUCTION Silanes or silicon hydrates are similar to fossil fuels. The element silicon is located directly below carbon in the system of chemical elements, which indicates a chemical behavior similar to carbon. It can also connect to longer chains. Fossil fuels are composed of a shorter or longer chain of carbon atoms along with a pair of hydrogen atoms connected (Fig. 1). Fig. 1 The simplest of the hydrocarbons is methane. It consists of one carbon atom connected to four hydrogen atoms: CH4. Silanes, likewise, are composed of a chain of silicon atoms, again with a pair of hydrogen atoms connected (Fig. 2). Fig. 2 The simplest representative of the silanes is monosilane, with four hydrogen atoms: SiH4, with a boiling point of 112°C. The first four silicon hydrates, already discovered at the beginning of the last century, self-ignite in air. Triand tetrasilane are gasoline-like liquids. Longer chains of silanes, however, were supposed to be unstable and thus not producible. In fact, this opinion about longer chained silanes is still present in most chemical institutes and publications; the discoverer of the so-called lower silanes, Prof. Alfred Stock, has stated this in his "Hydrides of Boron and Silicon" (Cornell University Press, 1933). Stock could never succeed with the isolation of pentasilane (Si5H10, Fig. 3). Fig. 3 MAIN SECTION The higher silanes, i.e. silanes with five and more silicon atoms in their chains, were successfully synthesized for the first time in 1970 at the University of Cologne, by Dr. Peter Plichta. The so-called higher silanes turned out to be stable. From seven Si atoms upward they no longer self-ignite. Together with their oily property they became easier to handle. Increasing chain length means more thermal stability and more power. This is the prerequisite for a potent fuel with a high power density. SILANE COMBUSTION Silanes – of all lengths – burn with the air’s oxygen to form brown silicon monoxide. Shown below is the combustion of pentasilane, filmed during laboratory tests at the University of Dortmund, broadcasted also on TV for the first time in January 2002 (Figs. 4 and 5). Fig. 6 High temperatures in a combustion chamber initiate the Si atoms to aggressively attack the remaining nitrogen (Fig. 7). This was discovered only in 1994 by Dr. Plichta. Fig. 7 Nitrogen Combustion Fig. 4 Nitrogen has the chemical formula N2 and consists of two nitrogen atoms connected by a triple bond. Triple bond connections are known to chemistry and chemical engineering as quite unstable, and so are easy to break up. Not so the triple bond connection of the nitrogen molecule, which is extremely stable. This unique and unexplainable behavior of the triple bond of the nitrogen molecule makes this gas an ideal and commonly used protecting medium for many chemical processes (even its name reflects this in some languages: "suffocating" or "extinguishing substance"). In a silane combustion chamber, however, the unbound and unconnected hot silicon atoms break the nitrogen molecule bond easily (Fig. 8). Fig. 5 But silanes have another property that remained hidden for decades. Silanes, like regular fossil fuels, are carriers of hydrogen. In regular engines, the hydrogen part of the silanes reacts with oxygen (Fig. 6). Fig. 8 Together they form - exothermally - the combustion product: silicon nitride (Si3N4). This substance carries four pairs of electrons positioned in tetrahedron geometry (Fig. 9) and by definition can be considered a solid inert “rare gas”. carbon part of the hydrocarbon burns, again only with oxygen: a gas, carbon dioxide, is produced. The nitrogen part of the atmosphere (80%; the thickness of the downward pointing arrow demonstrates the relation of the volumes) does not participate in the combustion at all. On the contrary, its presence is a disturbing and cooling factor in the reaction and absorbs a very valuable part of the produced energy of the combustion. Next, the combustion of silicone hydrates is demonstrated (Fig. 11): Fig. 9 Commonly, oxidation means the reaction with oxygen, from which the name stems. Oxidation with nitrogen caused fierce controversy among specialists, when a dangerous near disaster proved this new discovery: one of the greatest silicon producers of the world confirmed the reaction of activated silicon and nitrogen under pressure. Even the press reported this incident. Traditional fuel oxidation, the combustion hydrocarbons, is shown below (Fig. 10): of Fig. 11 Beginning the combustion, the 20% oxygen part of the air burns the hydrogen part of the silane to water (H2O). This is analogous to hydrocarbon combustion. The hot silicon radicals of the silane then become highly activated and burn with the nitrogen part of the atmosphere, producing silicon nitride (Si3N4). The inflowing air can be used in a stoechiometrically complete manner, when the silane fuel becomes enriched, e.g. with silicon dispersion. This revolutionary nitrogen reaction was proven at the facilities of one of the greatest silicon producers of the world (Fig. 12). Fig. 10 In a first step, the 20% oxygen part of the air burns the hydrogen part of the fuel, producing water (H2O). The Fig. 12 SPECIFICATIONS AND PROPERTIES OF SILANES Higher (longer chained) silanes, beginning with heptasilane (Si7H16), are stable oily liquids. They can be pumped and are not self-igniting with air. Some most important specifications of silanes compared to hydrocarbons can be seen in Table 1 vs. Table 2. Hydrocarbons material (hydrocarbon) methane CH4 ethane C2H6 propane C3H8 butane n-C4H10 i-C4H10 pentane n-C5H12 Cyclo-C5H10 hexane n-C6H14 Cyclo-C6H12 heptane n-C7H16 octane n-C8H18 The densities of the silicon hydrates (important for a better weight / volume ratio) are considerably higher as well. The reaction enthalpies are, contrary to the hydrocarbons, positive. boiling point [°C] ∆ Hf [kJ/mol] density [g/cm3] -182.5 -161.5 -74.898 0.424 MEASUREMENT OF SILANE COMBUSTION -183 -88 -84.727 -187.7 -42 0.5003 After producing higher silanes in quantities for calorimetric measurements, an initial investigation could be accomplished at the «ICT» (the Frauenhofer Institute in Berghausen near Karlsruhe). -135 -159 -0.5 -11.7 0.579 -130 -94 +36 +49 0.6262 0.746 -95 -80 +68.7 +83 0.66 0.81 -90.7 +98.4 0.681 -57 +126 0.703 Table 1 monosilane SiH4 disilane Si2H6 trisilane Si 3H8 tetrasilane n-Si 4H10 i-Si 4H10 pentasilane n-Si 5H12 Cyclo-Si 5H10 hexasilane n-Si 6H14 Cyclo-Si 6H12 heptasilane n-Si 7H16 octasilane n-Si 8H18 Freezing and boiling points of silanes are significantly higher than those of the corresponding hydrocarbons. freezing point [°C] Silanes material (silane) reactions, e.g. building molecules of longer chains. Positive values signalize endothermic reactions (needing thermal energy), while negative signs show exothermic behavior (giving thermal energy). freezing point [°C] boiling point [°C] ∆ Hf [kJ/mol] -184.7 -112.3 +34 -129.4 -14.8 +80 -117.4 +52.9 +121 0.739 -89.9 -99.4 +108.1 +101.7 +175 +180 0.795 -72.2 -10.5 +153.2 +194.3 +226 0.827 0.746 -44.7 +16.5 +193.6 +226 +268 0.847 -30.1 +226.8 density [g/cm3] 0.859 n.a. Table 2 The reaction enthalpy ( ∆Hf) reflects the thermal energy, which will be unbound while running through chemical The most important characteristics of some known fuels and oxidizers, along with a representative of the silanes, are shown in the next comparative table (Table 3). During these measurements, cyclopentasilane (CPS) was reacting (burned) merely with oxygen. Its specific impulse was already very high, even in this isolated stage of oxidization. The value is nearly identical to that of kerosene and the comparison with hydrazine (ADMH) shows minor differences as well. The second step of oxidization, the reaction of hot silicon with nitrogen, made the specific impulse of the silanes even more advantageous. composition (fuel & oxidizer) fuel [% wgt] CPS & O2 oxidizer [% wgt] specific impulse [N sec/kg] adiabatic combustion temp[°K] 25.41 6 74.584 2886 2863 H 2 & O2 11.19 0 88.810 3632 3684 RP1& O2 22.69 3 77.307 2890 3736 ADMH & N2O4 24.61 9 75.381 2777 3420 ADMH & O2 31.92 5 68.048 2997 3662 Table 3 Abbreviations for fuels and oxidizers: CPS = cyclopentasilane (Si5H10) RP1 = kerosene ADMH = asymmetric 1.1 dimethylhydrazine O2 = oxygen N2O4 = dinitrogentetraoxide Besides this, there are more very positive features of silanes. The specific density of silanes is higher then the density of the corresponding hydrocarbons. Silanes are completely non-toxic, while hydrazine for example is highly carcinogenic. The combustion products of silanes, water and silicon nitride, are non-toxic too and will not represent any atmospheric pollution menace. Silicon nitride can be further used easily with simple chemical transformations. USE OF SILANES IN AIR BREATHING PROPULSION SYSTEMS This newly discovered "oxidation" of silane fuel with nitrogen, the major part of the atmosphere, opens completely new perspectives for air-breathing rocket drives, which not only use oxygen for combustion but also the rest of air, i.e. the 80% nitrogen as well. This chemical reaction with nitrogen provides a new fuel with incredibly high energy, making it possible to design more powerful propulsion systems for high altitude flight and for totally new concepts in spacecraft design. For combustion engines, jet engines, hypersonic ramjets and even scramjets, the nitrogen combustion turns known combustion dynamics upside down, because it has the characteristics of an implosion. This revolutionary combustion method needs a newly conceived ceramic engine, which could be trend-setting for future engines. For reasons of patent protection, details cannot be disclosed. In contrast to common jet drives, this innovative design, together with a new construction method, allows propulsion without rotating elements such as turbine wheels, regardless of the craft’s speed. Clever management of the pressure automatically supplies the drive with the exactly calculated quantity of air necessary for oxidation, which is uniquely possible because of the nitrogen combustion. PRODUCTION OF SILANES As the synthesis of higher silanes was accomplished, it was demonstrated that with increased chain length, they become more stable, have an oily property, are not selfigniting, so not dangerous - in contrast to the current opinion of chemists. The basic production methods for measurement volumes are well established and proven. For industrial volume production, all production steps, along with feasible variants, are outlined and patented. CONCLUSION PERSPECTIVES: THE "INORGANIC CYCLE" The basis for the production of silane is silicon. Silicon is, following oxygen, the second most abundant element found in Earth's crust. Two thirds of our environment is based on structures of some derivates of silicates, i.e. silicon connected to oxygen, forming sand and rock. Establishing huge silane production facilities, preferably in sun-belt deserts, where electric energy for the production can be gained directly from widely set solarcell plants, plus optimized industrial procedures (like the patented Modified Mueller-Rochow-Synthesis) can deliver a very powerful fuel of inexhaustible resources: silicon, commonly sand. By using (burning) this fuel in air breathing rocket jet engines or – for terrestrial movements – in (also well patented) Silane-DieselWankel engines, all combustion products (water and silicon nitride) are stable, non-toxic and completely recyclable. All recycling steps of various possibilities, according to local or global needs, result in energy (e.g. burning methane, synthesised from silicon nitride) or in natural final materials (like water or nitrogen) not representing any stress to the environment at all. Thus, an artificial inorganic silicon cycle will occur, just as nature operates the well-known organic carbon cycle, keeping balance in Earth's resources (Fig. 13, on the following page). Silane fuels provide the basis for spacecraft designs that incorporate a gradual ascent to space by using both the oxygen and the nitrogen in the air until reaching the limit of the atmosphere. At the limit of our atmosphere, only minimal volumes of onboard fuel and oxidizer would be required to continue to orbit. ACKNOWLEDGMENTS New and innovative propulsion systems using these more efficient fuels are the basis for completely new spacecraft designs that do not require the compromises of aerodynamic principles currently necessary to accommodate the ascent to and descent from orbit. New spacecraft designs that incorporate these more efficient propulsion systems will lead to vehicles that can achieve orbit via low ascent angles and without multi-stage engines. Such an innovative spacecraft design will be proposed in another presentation at this meeting by the same authors. REFERENCES The authors want to thank hereby in general all persons and institutions involved in the preparation of this presentation for their valuable and highly appreciated support: David Zornes’ invitation to SAE WAC, Peter Plichta, Erika Kirgis, Franz Willi, and Linda Bell Carlson. ̇ ̇ ̇ Benzin Aus Sand / Die Silan-Revolution (Fuel, made of Sand / The Silane-Revolution) by Peter Plichta, Langen-Müller Press, 2001 NET-Journal (Switzerland) Vol. 7/2002, pg 4ff Raum&Zeit (Germany) Vol. 115/2002, pg.74ff CONTACT Nitronics Aerospace Technologies, LLC 3116 S.W. 153rd Drive Beaverton, Oregon 97006 APPENDIX Fig. 13