Rocket propellant (updated)

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https://en.wikipedia.org/wiki/Rocket_propellant

 

A Delta IV Heavy during liftoff. The rocket is entirely fuelled with Liquid Hydrogen and Liquid Oxygen cryogenic propellants.

 

Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical rocket, or from an external source, as with ion engines.

Overview

Rockets create thrust by expelling mass backward at high velocity. The thrust produced can be calculated by multiplying the mass flow rate of the propellants by their exhaust velocity relative to the rocket (specific impulse). A rocket can be thought of as being accelerated by the pressure of the combusting gases against the combustion chamber and nozzle, not by "pushing" against the air behind or below it. Rocket engines perform best in outer space because of the lack of air pressure on the outside of the engine. In space it is also possible to fit a longer nozzle without suffering from flow separation.

Most chemical propellants release energy through redox chemistry, more specifically combustion. As such, both an oxidizing agent and a reducing agent must be present in the fuel mixture. Decomposition, such as that of highly unstable peroxide bonds in monopropellant rockets, can also be the source of energy.

In the case of bipropellant liquid rockets, a mixture of reducing fuel and oxidizing oxidizer is introduced into a combustion chamber, typically using a turbopump to overcome the pressure. As combustion takes place, the liquid propellant mass is converted into a huge volume of gas at high temperature and pressure. This exhaust stream is ejected from the engine nozzle at high velocity, creating an opposing force that propels the rocket forward in accordance with Newton's laws of motion.

Chemical rockets can be grouped by phase. Solid rockets use propellant in the solid phase, liquid fuel rockets use propellant in the liquid phase, gas fuel rockets use propellant in the gas phase, and hybrid rockets use a combination of solid and liquid or gaseous propellants.

In the case of solid rocket motors, the fuel and oxidizer are combined when the motor is cast. Propellant combustion occurs inside the motor casing, which must contain the pressures developed. Solid rockets are typically have higher thrust, less specific impulse, shorter burn times, and a higher mass than liquid rockets, and additionally cannot be stopped once lit.

Rocket stages

In space, the maximum change in velocity that a rocket stage can impart on its payload is primarily a function of its mass ratio and its exhaust velocity. This relationship is described by the rocket equation. Exhaust velocity is dependent on the propellant and engine used and closely related to specific impulse, the total energy delivered to the rocket vehicle per unit of propellant mass consumed. Mass ratio can also be affected by the choice of a given propellant.

Rocket stages that fly through the atmosphere usually use lower performing, high molecular mass, high-density propellants due to the smaller and lighter tankage required. Upper stages, which mostly or only operate in the vacuum of space, tend to use the high energy, high performance, low density liquid hydrogen fuel.

Solid chemical rockets

Solid propellants come in two main types. "Composites" are composed mostly of a mixture of granules of solid oxidizer, such as ammonium nitrate, ammonium dinitramide, ammonium perchlorate, or potassium nitrate in a polymer binding agent, with flakes or powders of energetic fuel compounds (examples: RDX, HMX, aluminium, beryllium). Plasticizers, stabilizers, and/or burn rate modifiers (iron oxide, copper oxide) can also be added.

Single-, double-, or triple-bases (depending on the number of primary ingredients) are homogeneous mixtures of one to three primary ingredients. These primary ingredients must include fuel and oxidizer and often also include binders and plasticizers. All components are macroscopically indistinguishable and often blended as liquids and cured in a single batch. Ingredients can often have multiple roles. For example, RDX is both a fuel and oxidizer while nitrocellulose is a fuel, oxidizer, and plasticizer.

Further complicating categorization, there are many propellants that contain elements of double-base and composite propellants, which often contain some amount of energetic additives homogeneously mixed into the binder. In the case of gunpowder (a pressed composite without a polymeric binder) the fuel is charcoal, the oxidizer is potassium nitrate, and sulphur serves as a reaction catalyst while also being consumed to form a variety of reaction products such as potassium sulfide.

The newest nitramine solid propellants based on CL-20 (HNIW) can match the performance of NTO/UDMH storable liquid propellants, but cannot be throttled or restarted.

Advantages of solid propellants

Solid propellant rockets are much easier to store and handle than liquid propellant rockets. High propellant density makes for compact size as well. These features plus simplicity and low cost make solid propellant rockets ideal for military applications.

Their simplicity also makes solid rockets a good choice whenever large amounts of thrust are needed and the cost is an issue. The Space Shuttle and many other orbital launch vehicles use solid-fueled rockets in their boost stages (solid rocket boosters) for this reason.

Disadvantages of solid propellants

Solid fuel rockets have lower specific impulse, a measure of propellant efficiency, than liquid fuel rockets. As a result, the overall performance of solid upper stages is less than liquid stages even though the solid mass ratios are usually in the .91 to .93 range, as good as or better than most liquid propellant upper stages. The high mass ratios possible with these unsegmented solid upper stages is a result of high propellant density and very high strength-to-weight ratio filament-wound motor casings.

A drawback to solid rockets is that they cannot be throttled in real time, although a programmed thrust schedule can be created by adjusting the interior propellant geometry. Solid rockets can be vented to extinguish combustion or reverse thrust as a means of controlling range or accommodating warhead separation. Casting large amounts of propellant requires consistency and repeatability to avoid cracks and voids in the completed motor. The blending and casting take place under computer control in a vacuum, and the propellant blend is spread thin and scanned to assure no large gas bubbles are introduced into the motor.

Solid fuel rockets are intolerant to cracks and voids and require post-processing such as X-ray scans to identify faults. The combustion process is dependent on the surface area of the fuel. Voids and cracks represent local increases in burning surface area, increasing the local temperature, which increases the local rate of combustion. This positive feedback loop can easily lead to catastrophic failure of the case or nozzle.

Solid propellant history

Solid rocket propellant was first developed during the 13th century under the Chinese Song dynasty. The Song Chinese first used gunpowder in 1232 during the military siege of Kaifeng.

During the 1950s and 60s researchers in the United States developed ammonium perchlorate composite propellant (APCP). This mixture is typically 69-70% finely ground ammonium perchlorate (an oxidizer), combined with 16-20% fine aluminium powder (a fuel), held together in a base of 11-14% polybutadiene acrylonitrile (PBAN) or Hydroxyl-terminated polybutadiene (polybutadiene rubber fuel). The mixture is formed as a thickened liquid and then cast into the correct shape and cured into a firm but flexible load-bearing solid. Historically the tally of APCP solid propellants is relatively small. The military, however, uses a wide variety of different types of solid propellants some of which exceed the performance of APCP. A comparison of the highest specific impulses achieved with the various solid and liquid propellant combinations used in current launch vehicles is given in the article on solid-fuel rockets.

In the 1970s and 1980s, the U.S. switched entirely to solid-fueled ICBMs: the LGM-30 Minuteman and LG-118A Peacekeeper (MX). In the 1980s and 1990s, the USSR/Russia also deployed solid-fueled ICBMs (RT-23, RT-2PM, and RT-2UTTH), but retains two liquid-fueled ICBMs (R-36 and UR-100N). All solid-fueled ICBMs on both sides had three initial solid stages, and those with multiple independently targeted warheads had a precision maneuverable bus used to fine tune the trajectory of the re-entry vehicles.

Liquid chemical rocket propellants

The main types of liquid propellants are storable propellants, which tend to be hypergolic, and cryogenic propellants. 

Advantages of liquid propellant

Liquid-fueled rockets have higher specific impulse than solid rockets and are capable of being throttled, shut down, and restarted. Only the combustion chamber of a liquid-fueled rocket needs to withstand high combustion pressures and temperatures. Cooling can be done regeneratively with the liquid propellant. On vehicles employing turbopumps, the propellant tanks are at a lower pressure than the combustion chamber, decreasing tank mass. For these reasons, most orbital launch vehicles use liquid propellants.

The primary specific impulse advantage of liquid propellants is due to the availability of high-performance oxidizers. Several practical liquid oxidizers (liquid oxygen, dinitrogen tetroxide, and hydrogen peroxide) are available which have better specific impulse than the ammonium perchlorate used in most solid rockets when paired with suitable fuels.

Some gases, notably oxygen and nitrogen, may be able to be collected from the upper atmosphere, and transferred up to low-Earth orbit for use in propellant depots at substantially reduced cost.

Disadvantages of liquid propellants

The main difficulties with liquid propellants are also with the oxidizers. Storable oxidizers, such as nitric acid and nitrogen tetroxide, tend to be extremely toxic and highly reactive, while cryogenic propellants by definition must be stored at low temperature and can also have reactivity/toxicity issues. Liquid oxygen (LOX) is the only flown cryogenic oxidizer - others such as FLOX, a fluorine/LOX mix, have never been flown due to instability, toxicity, and explosivity. Several other unstable, energetic, and toxic oxidizers have been proposed: liquid ozone (O₃), ClF₃, and ClF₅.

Liquid-fueled rockets require potentially troublesome valves, seals, and turbopumps, which increase the cost of the rocket. Turbopumps are particularly troublesome due to high performance requirements.

Current cryogenic types

• Liquid oxygen (LOX) and highly refined kerosene (RP-1). Used for the first stages of the Atlas V, Falcon, Soyuz, Zenit, and developmental rockets like Angara and Long March 6. This combination is widely regarded as the most practical for boosters that lift off at ground level and therefore must operate at full atmospheric pressure.
• LOX and liquid hydrogen. Used on the Centaur upper stage, the Delta IV rocket, the H-IIA rocket, most stages of the European Ariane 5, and the Space launch system core and upper stages.
• LOX and liquid methane will be used on several rockets in development, including Vulcan, New Glenn, and SpaceX Starship.

Current storable types

• Dinitrogen tetroxide (N₂O₄) and hydrazine (N₂H₄), MMH, or UDMH. Used in military, orbital, and deep space rockets because both liquids are storable for long periods at reasonable temperatures and pressures. N₂O₄/UDMH is the main fuel for the Proton rocket, older Long March rockets (LM 1-4), PSLV, Fregat, and Briz-M upper stages. This combination is hypergolic, making for attractively simple ignition sequences. The major inconvenience is that these propellants are highly toxic and require careful handling.
• Monopropellants such as hydrogen peroxide, hydrazine, and nitrous oxide are primarily used for attitude control and spacecraft station-keeping where their long-term storability, simplicity of use, and ability to provide the tiny impulses needed outweighs their lower specific impulse as compared to bipropellants. Hydrogen peroxide is also used to drive the turbopumps on the first stage of the Soyuz launch vehicle.

Mixture ratio

The theoretical exhaust velocity of a given propellant chemistry is a function of the energy released per unit of propellant mass (specific energy). In chemical rockets, unburned fuel or oxidizer represents the loss of chemical potential energy, which reduces the specific energy. However, most rockets run fuel-rich mixtures, which result in lower theoretical exhaust velocities.

However, fuel-rich mixtures also have lower molecular weight exhaust species. The nozzle of the rocket converts the thermal energy of the propellants into directed kinetic energy. This conversion happens in the time it takes for the propellants to flow from the combustion chamber through the engine throat and out the nozzle, usually on the order of one millisecond. Molecules store thermal energy in rotation, vibration, and translation, of which only the latter can easily be used to add energy to the rocket stage. Molecules with fewer atoms (like CO and H₂) have fewer available vibrational and rotational modes than molecules with more atoms (like CO₂ and H₂O). Consequently, smaller molecules store less vibrational and rotational energy for a given amount of heat input, resulting in more translation energy being available to be converted to kinetic energy. The resulting improvement in nozzle efficiency is large enough that real rocket engines improve their actual exhaust velocity by running rich mixtures with somewhat lower theoretical exhaust velocities.

The effect of exhaust molecular weight on nozzle efficiency is most important for nozzles operating near sea level. High expansion rockets operating in a vacuum see a much smaller effect, and so are run less rich.

LOX/hydrocarbon rockets are run slightly rich (O/F mass ratio of 3 rather than stoichiometric of 3.4 to 4) because the energy release per unit mass drops off quickly as the mixture ratio deviates from stoichiometric. LOX/LH₂ rockets are run very rich (O/F mass ratio of 4 rather than stoichiometric 8) because hydrogen is so light that the energy release per unit mass of propellant drops very slowly with extra hydrogen. In fact, LOX/LH₂ rockets are generally limited in how rich they run by the performance penalty of the mass of the extra hydrogen tankage instead of the underlying chemistry.

Another reason for running rich is that off-stoichiometric mixtures burn cooler than stoichiometric mixtures, which makes engine cooling easier. Because fuel-rich combustion products are less chemically reactive (corrosive) than oxidizer-rich combustion products, a vast majority of rocket engines are designed to run fuel-rich. At least one exception exists: the Russian RD-180 preburner, which burns LOX and RP-1 at a ratio of 2.72.

Additionally, mixture ratios can be dynamic during launch. This can be exploited with designs that adjust the oxidizer to fuel ratio (along with overall thrust) throughout a flight to maximize overall system performance. For instance, during lift-off thrust is more valuable than specific impulse, and careful adjustment of the O/F ratio may allow higher thrust levels. Once the rocket is away from the launchpad, the engine O/F ratio can be tuned for higher efficiency.

Propellant density

Although liquid hydrogen gives a high I_sp, its low density is a disadvantage: hydrogen occupies about 7x more volume per kilogram than dense fuels such as kerosene. The fuel tankage, plumbing, and pump must be correspondingly larger. This increases the vehicle's dry mass, reducing performance. Liquid hydrogen is also relatively expensive to produce and store, and causes difficulties with design, manufacture, and operation of the vehicle. However, liquid hydrogen is extremely well suited to upper stage use where I_sp is at a premium and thrust to weight ratios are less relevant.

Dense propellant launch vehicles have a higher takeoff mass due to lower I_sp, but can more easily develop high takeoff thrusts due to the reduced volume of engine components. This means that vehicles with dense-fueled booster stages reach orbit earlier, minimizing losses due to gravity drag and reducing the effective delta-v requirement.

The proposed tripropellant rocket uses mainly dense fuel while at low altitude and switches across to hydrogen at higher altitude. Studies in the 1960s proposed single stage to orbit vehicles using this technique. The Space Shuttle approximated this by using dense solid rocket boosters for the majority of the thrust during the first 120 seconds. The main engines burned a fuel-rich hydrogen and oxygen mixture, operating continuously throughout the launch but providing the majority of thrust at higher altitudes after SRB burnout.

Other chemical propellants

Hybrid propellants

Hybrid propellants: a storable oxidizer used with a solid fuel, which retains most virtues of both liquids (high ISP) and solids (simplicity).

A hybrid rocket usually has a solid fuel and a liquid or NEMA oxidizer. The fluid oxidizer can make it possible to throttle and restart the motor just like a liquid-fueled rocket. Hybrid rockets can also be environmentally safer than solid rockets since some high-performance solid-phase oxidizers contain chlorine (specifically composites with ammonium perchlorate), versus the more benign liquid oxygen or nitrous oxide often used in hybrids. This is only true for specific hybrid systems. There have been hybrids which have used chlorine or fluorine compounds as oxidizers and hazardous materials such as beryllium compounds mixed into the solid fuel grain. Because just one constituent is a fluid, hybrids can be simpler than liquid rockets depending motive force used to transport the fluid into the combustion chamber. Fewer fluids typically mean fewer and smaller piping systems, valves and pumps (if utilized).

Hybrid motors suffer two major drawbacks. The first, shared with solid rocket motors, is that the casing around the fuel grain must be built to withstand full combustion pressure and often extreme temperatures as well. However, modern composite structures handle this problem well, and when used with nitrous oxide and a solid rubber propellant (HTPB), relatively small percentage of fuel is needed anyway, so the combustion chamber is not especially large.

The primary remaining difficulty with hybrids is with mixing the propellants during the combustion process. In solid propellants, the oxidizer and fuel are mixed in a factory in carefully controlled conditions. Liquid propellants are generally mixed by the injector at the top of the combustion chamber, which directs many small swift-moving streams of fuel and oxidizer into one another. Liquid-fueled rocket injector design has been studied at great length and still resists reliable performance prediction. In a hybrid motor, the mixing happens at the melting or evaporating surface of the fuel. The mixing is not a well-controlled process and generally, quite a lot of propellant is left unburned, which limits the efficiency of the motor. The combustion rate of the fuel is largely determined by the oxidizer flux and exposed fuel surface area. This combustion rate is not usually sufficient for high power operations such as boost stages unless the surface area or oxidizer flux is high. Too high of oxidizer flux can lead to flooding and loss of flame holding that locally extinguishes the combustion. Surface area can be increased, typically by longer grains or multiple ports, but this can increase combustion chamber size, reduce grain strength and/or reduce volumetric loading. Additionally, as the burn continues, the hole down the center of the grain (the 'port') widens and the mixture ratio tends to become more oxidizer rich.

There has been much less development of hybrid motors than solid and liquid motors. For military use, ease of handling and maintenance have driven the use of solid rockets. For orbital work, liquid fuels are more efficient than hybrids and most development has concentrated there. There has recently been an increase in hybrid motor development for nonmilitary suborbital work:

• Several universities have recently experimented with hybrid rockets. Brigham Young University, the University of Utah and Utah State University launched a student-designed rocket called Unity IV in 1995 which burned the solid fuel hydroxy-terminated polybutadiene (HTPB) with an oxidizer of gaseous oxygen, and in 2003 launched a larger version which burned HTPB with nitrous oxide. Stanford University researches nitrous-oxide/paraffin wax hybrid motors. UCLA has launched hybrid rockets through an undergraduate student group since 2009 using HTPB.
• The Rochester Institute of Technology was building an HTPB hybrid rocket to launch small payloads into space and to several near-Earth objects. Its first launch was in the Summer of 2007.
• Scaled Composites SpaceShipOne, the first private manned spacecraft, was powered by a hybrid rocket burning HTPB with nitrous oxide: RocketMotorOne. The hybrid rocket engine was manufactured by SpaceDev. SpaceDev partially based its motors on experimental data collected from the testing of AMROC's (American Rocket Company) motors at NASA's Stennis Space Center's E1 test stand.

Gaseous propellants

GOX (gaseous oxygen) was used as the oxidizer for the Buran program's orbital maneuvering system.

Inert propellants

Some rocket designs impart energy to their propellants with external energy sources. For example, water rockets use a compressed gas, typically air, to force the water reaction mass out of the rocket.

Ion thruster

Ion thrusters ionize a neutral gas and create thrust by accelerating the ions (or the plasma) by electric and/or magnetic fields.

Thermal rockets

Thermal rockets use inert propellants of low molecular weight that are chemically compatible with the heating mechanism at high temperatures. Solar thermal rockets and nuclear thermal rockets typically propose to use liquid hydrogen for a specific impulse of around 600–900 seconds, or in some cases water that is exhausted as steam for a specific impulse of about 190 seconds. Nuclear thermal rockets use the heat of nuclear fission to add energy to the propellant. Some designs separate the nuclear fuel and working fluid, minimizing the potential for radioactive contamination, but nuclear fuel loss was a persistent problem during real-world testing programs. Solar thermal rockets use concentrated sunlight to heat a propellant, rather than using a nuclear reactor.

Compressed gas

For low performance applications, such as attitude control jets, compressed inert gases such as nitrogen have been employed. Energy is stored in the pressure of the inert gas. However, due to the low density of all practical gases and high mass of the pressure vessel required to contain it, compressed gases see little current use.

Nuclear plasma

In Project Orion and other nuclear pulse propulsion proposals, the propellant would be plasma debris from a series of nuclear explosions.

Robert Zubrin (updated)

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Robert_Zubrin

 

Robert Zubrin
Photo of Zubrin by the Mars Society
Born	April 9, 1952 (age 67) Brooklyn, New York
Nationality	American
Alma mater	University of Rochester (B.A) University of Washington (M.S), (PhD)
Known for	Mars Direct Mars Society The Case for Mars Energy Victory
Scientific career
Fields	Aerospace engineering
Institutions	Martin Marietta Pioneer Astronautics

Robert Zubrin is an American aerospace engineer and author, best known for his advocacy of human exploration of Mars. He and his colleague at Martin Marietta, David Baker, were the driving force behind Mars Direct, a proposal in a 1990 research paper intended to produce significant reductions in the cost and complexity of such a mission. The key idea was to use the Martian atmosphere to produce oxygen, water, and rocket propellant for the surface stay and return journey. A modified version of the plan was subsequently adopted by NASA as their "design reference mission". He questions the delay and cost-to-benefit ratio of first establishing a base or outpost on an asteroid or another Apollo program-like return to the Moon, as neither would be able to provide all of its own oxygen, water, or energy; these resources are producible on Mars, and he expects people would be there thereafter.

Disappointed with the lack of interest from government in Mars exploration and after the success of his book The Case for Mars (1996), as well as leadership experience at the National Space Society, Zubrin established the Mars Society in 1998. This is an international organization advocating a human mission to Mars as a goal, by private funding if possible.

Early life

Robert Zubrin was born in Brooklyn, New York on Apr 9, 1952. He was a science teacher for 7 years before becoming an engineer.

Qualifications and professional experience

Zubrin holds a B.A. in Mathematics from the University of Rochester (1974), a M.S. in Nuclear Engineering (1984), a M.S. in Aeronautics and Astronautics (1986), and a Ph.D. in Nuclear Engineering (1992) — all from the University of Washington. He has developed a number of concepts for space propulsion and exploration, and is the author of over 200 technical and non-technical papers and several books. He was a member of Lockheed Martin's scenario development team charged with developing strategies for space exploration. He was also "a senior engineer with the Martin Marietta Astronautics company, working as one of its leaders in development of advanced concepts for interplanetary missions". He is also President of both the Mars Society and Pioneer Astronautics, a private company that does research and development on innovative aerospace technologies. Zubrin is the co-inventor on a U.S. design patent and a U.S. utility patent on a hybrid rocket/airplane, and on a U.S. utility patent on an oxygen supply system (see links below). He was awarded his first patent at age 20 in 1972 for Three Player Chess. His inventions also include the nuclear salt-water rocket and co-inventor (with Dana Andrews) of the magnetic sail. Zubrin is fellow at Center for Security Policy.

Pioneer Energy

In 2008, Zubrin founded Pioneer Energy, a research and development firm headquartered in Lakewood, Colorado. The company's focus is to develop mobile Enhanced Oil Recovery (EOR) systems that can enable CO2-based EOR for both small and large oil producers in the United States. The company has also developed a number of new processes for manufacturing synthetic fuels.

Books

• The Case for Mars: The Plan to Settle the Red Planet and Why We Must (1996), with Richard Wagner. This outlines the Mars Direct plan along with speculation about the economic, social and technical viability of future Mars colonization. Revised and updated in 2011.
• Entering Space: Creating a Spacefaring Civilization (1999). This ranges from the current status quo and innovative startups of the aerospace industry, through exploration and colonization of Mars, to a more futuristic look at humanity's possible colonization of the solar system and the feasibility of interstellar travel with known physics.
• Mars On Earth: The Adventures of Space Pioneers in the High Arctic (2003). Zubrin recounts the origins and progress of the Mars Society's Mars Analog Research Station project, including a variety of perils, both mundane and adventurous, that were overcome in establishing the first analog Mars habitat on Devon Island in the high Arctic. He offers highlights of what has been learned so far through that effort.
• First Landing (2001), a hard science fiction novel about a future Mars flight using the Mars Direct plan.
• The Holy Land (2003). This is an "SF satire on the Middle East crisis and the War on Terrorism, and concerns what happens when the liberal Western Galactic Empire relocates the oppressed Minervan sect to their ancient homeland of Kennewick, Washington, in the midst of a United States ruled by Christian fundamentalist fanatics". The story was partly inspired by Čapek's War with the Newts.
• Benedict Arnold: A Drama of the American Revolution in Five Acts (2005). This is an effort to humanize and show the multiple dimensions of Benedict Arnold, and to contrast the democratic values embodied in the spirit of the Revolution with the socially bankrupt classism embodied in the British subjects who won Arnold to their side.
• Energy Victory: Winning the War on Terror by Breaking Free of Oil (2007). An expansion on his recent articles criticizing both reliance on oil and the potential for hydrogen energy, while highlighting the benefits of switching more toward methanol and ethanol. It carries an endorsement from former CIA director James Woolsey.
• How to Live on Mars (2008). A tongue-in-cheek technically accurate guidebook for Mars-bound Earthlings about how to survive and thrive on the Red Planet, written from the point of view of a 22nd-century Mars native.
• Merchants of Despair: Radical Environmentalists, Criminal Pseudo-Scientists, and the Fatal Cult of Antihumanism (2011). This traces the history of antihumanism over the last two centuries, from Thomas Malthus and the eugenics movement through to the anti-nuclear and global warming campaigns. Zubrin argues that these movements have all represented an attempt to gain oppressive political control through the restriction of human activities and freedom.
• Mars Direct: Space Exploration, the Red Planet, and the Human Future (2013). This e-book looks at the current situation of NASA and outlines a Mars Direct mission proposal with the SpaceX Dragon, and considers the implications of interplanetary exploration for humanity.
• The Case for Space: How the Revolution in Spaceflight Opens Up a Future of Limitless Possibility Prometheus Books (2019)

Books edited or co-authored

Zubrin has also edited or co-edited the following books, most of which include his contributions:

• Mars Direct: A Simple, Robust, and Cost Effective Architecture for the Space Exploration Initiative (1991), co-edited by D.A.V.I.D. Baker and Owen Gwyne. This contains a series of rationales and data regarding the proposal of plan Mars Direct.
• Islands in the Sky: Bold New Ideas for Colonizing Space (1996), co-edited with Stanley Schmidt. This is a collection of fifteen selected non-fiction entries that had been published in Analog magazine over the years; it includes five articles authored or co-authored by Zubrin, including "The Hypersonic Skyhook", "Mars Direct: A Proposal for the Rapid Exploration and Colonization of the Red Planet" (co-authored with David A. Baker), "Colonizing the Outer Solar System", "Terraforming Mars" (co-authored with Christopher McKay), and "The Magnetic Sail". Notable additional contributors include Robert L. Forward and the godfather of terraforming, Martyn J. Fogg, each of whom contributed two articles.
• From Imagination to Reality: Mars Exploration Studies of the Journal of the British Interplanetary Society : Precursors and Early Piloted Exploration Missions (1997).
• From Imagination to Reality: Mars Exploration Studies of the Journal of the British Interplanetary Society : Base Building, Colonization and Terraformation (1997).
• Proceedings of the Founding Convention of the Mars Society (1999), co-edited with Maggie Zubrin. This contains articles corresponding to talks presented at the founding convention of the Mars Society in Boulder, Colorado in August 1998; it includes contributions from Zubrin, Buzz Aldrin, Martyn Fogg, and many others.
• On to Mars: Colonizing a New World (2002 Apogee Books), co-edited with Frank Crossman. This contains articles corresponding to talks presented at the annual conventions of the Mars Society in Boulder in 1999, in Toronto, Ontario, Canada in 2000, and at Stanford University, Palo Alto, California in 2001.
• On to Mars 2: Exploring and Settling a New World (2005 Apogee Books), co-edited with Frank Crossman. This contains over 130 articles corresponding to talks presented at the annual conventions of the Mars Society in Boulder in 2002, in Eugene, Oregon in 2003, and in Chicago, Illinois in 2004.

The ethics of terraforming

Dr. Zubrin is known as an advocate of a moderately anthropocentric position in the ethics of terraforming. Discussions of the ethics of terraforming often make reference to a series of public debates Zubrin has held with his friend Christopher McKay, who advocates a moderately biocentric position on the ethics of terraforming. For example, a written account of some of these debates is available in On to Mars: Colonizing a New World, as a joint article, "Do Indigenous Martian Bacteria have Precedence over Human Exploration?" (pp. 177–182)

Cultural references

An aging Robert Zubrin also appears as a background character in The Martian Race (1999) by Gregory Benford, a science fiction novel depicting early human explorers on Mars in the very near future. Benford, who is also an astrophysicist, is a longtime member of both the board of directors and the steering committee of the Mars Society. 

Robert Zubrin was also featured in a 2007 CBC Television documentary special, The Passionate Eye, dubbed "The Mars Underground".

The songwriter and musician Frank Black (alias Black Francis of the Pixies) penned an homage to Zubrin, "Robert Onion", on the album Dog in the Sand. The lyrics are in the form of an acrostic, spelling "Robert The Case For Mars Zubrin".

In 2010 Robert Zubrin was featured in the Symphony of Science video "The Case for Mars" along with Carl Sagan, Brian Cox, and Penelope Boston.

The fictional character Dr. Zachary Walzer in the 2010-11 independent VODO series Pioneer One was inspired by Zubrin.

In 2016, Zubrin was one of several scientists and engineers interviewed in the National Geographic miniseries Mars. 

Patents

• U.S. design patent D405,750, "Reusable rocket airplane"
• U.S. Patent 6,119,985, "Reusable rocket-propelled high altitude airplane and method and apparatus for mid-air oxidizer transfer to said airplane"
• U.S. Patent 6,347,627, "Nitrous oxide based oxygen supply system"
• U.S. Patent 3,652,091, "Three-player chess board"

Richard C. Hoagland

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From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Richard_C._Hoagland

 

Richard C. Hoagland
Born	Richard Charles Hoagland April 25, 1945 Morristown, New Jersey, U.S.
Nationality	American
Citizenship	United States
Known for	Theories about advanced ancient civilizations colonizing the solar system; accusations of corruption of NASA and U.S. government
Notable work	The Monuments of Mars: A City on the Edge of Forever
Awards	International Angstrom Medal for Excellence in Science, 1993. Ig Nobel Prize for Astronomy, 1997.

Richard Charles Hoagland (born April 25, 1945), is an American author, and a proponent of various conspiracy theories about NASA, lost alien civilizations on the Moon and on Mars and other related topics. Hoagland has been documented to misappropriate others' professional achievements and is widely described as a conspiracy theorist and fringe pseudoscientist.

Background

Hoagland has no education beyond the high school level. According to Hoagland's own curriculum vitae he has no advanced training, schooling or degrees in any scientific field. Hoagland asserts he was a Curator of Astronomy and Space Science at the Springfield Science Museum, 1964–1967, and Assistant Director at the Gengras Science Center in West Hartford, Connecticut, 1967–1968, and a Science Advisor to CBS News during the Apollo program, 1968–1971. In July 1968, Hoagland filed a copyright registration for a planetarium presentation and show script called The Grand Tour.

A popular planetarium lecturer at the Springfield Science Museum, Hoagland produced a program called "Mars: Infinity to 1965" to coincide with the Mariners 3 and 4 missions. He designed a room with special equipments to display the relative positions of the Earth, Mars and the Mariners during their trip and thereafter contracted with NASA to relay the pictures of the Martian surface, on a near-live-feed, to the general audience. Hoagland co-hosted a radio program for WTIC (AM) in Hartford, Connecticut, The Night of the Encounter, along with Dick Bertel, covering the July 14, 1965 Mariner 4 flyby of the planet Mars. Local newspapers had noted the radio broadcast to be history's first laser audio transmission.

In 1976, Hoagland, an avid Star Trek fan, initiated a letter-writing campaign that successfully persuaded President Gerald Ford to name the first Space Shuttle the Enterprise, replacing the previously slated name for the prototype vehicle, Constitution.

Hoagland authored the book The Monuments of Mars: A City on the Edge of Forever (published in 1987), and co-authored the book Dark Mission: The Secret History of NASA, which was ranked 21st on November 18, 2007 on The New York Times Best Seller list for paperback nonfiction. Richard Grossinger, the founder of North Atlantic Books, writes that Monuments became the most successful title published by North Atlantic, and that at its peak the book sold over 2000 copies per month. Grossinger also reports that Hoagland wrote much of the book while in Los Angeles county jail.

Hoagland runs The Enterprise Mission website, which he describes as "an independent NASA watchdog and research group, the Enterprise Mission, attempting to figure out how much of what NASA has found in the solar system over the past 50 years has actually been silently filed out of sight as classified material, and therefore totally unknown to the American people."

Hoagland appeared regularly as the "Science Advisor" for Coast to Coast AM, a late-night radio talk show, until being replaced by Robert Zimmerman in July 2015.

While Hoagland makes frequent reference to his receipt of the "International Angstrom Medal for Excellence in Science" in August 1993, the organization that awarded the medal, The Angstrom Foundation Aktiebolag, founded by Lars-Jonas Ångström, was not authorized by Uppsala University or the Royal Swedish Academy of Sciences to make use of the academy's Anders Jonas Ångström memorial medal. The academy has long authorized only Uppsala University to use their medal for the Ångström's Prize (Ångströms premium), awarded yearly by Uppsala professors to physics students. Mr. Ångström stated in May 2000 that although his award to Hoagland was a mistake, he acted with good faith and with good intentions.

Claims by Hoagland

Hoagland claims the source of a so-called NASA "coverup", with relation to the "Face on Mars" and other related structures, is the result of a report commissioned by NASA authored by the Brookings Institution, the so-called Brookings Report. The 1960 report, entitled "Proposed Studies on the Implications of Peaceful Space Activities for Human Affairs", is claimed by Hoagland, on page 216 of the report, to instruct NASA to deliberately withhold from the public any evidence it may find of extraterrestrial activity, specifically, on the moon, Mars or Venus.

Hoagland has also proposed a form of physics he calls "hyperdimensional physics", which he claims represents a more complete implementation of James Clerk Maxwell's original 20 quaternion equations, instead of the original Maxwell's equations as amended by Oliver Heaviside commonly taught today. These ideas are rejected by the mainstream physics community as unfounded.

Hoagland claims the "Face on Mars" is part of a city built on Cydonia Planitia consisting of very large pyramids and mounds arranged in a geometric pattern. To Hoagland, this is evidence that an advanced civilization might once have existed on Mars. In the years since its discovery, the "face" has been near-universally accepted as an optical illusion, an example of the psychological phenomenon of pareidolia. Similar optical illusions can be found in the geology of Earth; examples include the Old Man of the Mountain, the Pedra da Gávea, and Stac Levenish.

Although the Pioneer 10 plaque was designed entirely by Carl Sagan, Linda Salzman Sagan, and Frank Drake, Hoagland has inaccurately asserted that he co-created the plaque with Eric Burgess. In 1990, Hoagland tried to take credit for the plaque, asserting that "Carl for many years has been taking public credit for the Pioneer plaque which, of course, Eric Burgess and I conceived." Later that year Hoagland went so far as to claim he designed the plaque when he said "Carl... was involved with Eric Burgess and me in the design of [the] message." Burgess' own account is at odds with Hoagland's design claims, stating that "The design itself was created by Carl Sagan and Frank Drake, with the artistic help of Sagan’s then-wife Linda Salzman Sagan", without mentioning Hoagland at all. Sagan's own correspondence regarding the matter also contradict Hoagland's claims, specifically saying that "he did not contribute one bit of data towards the message design." Burgess recalls similarly, adding that all Hoagland did with regard to the plaque "was support me and say it's a good idea." And yet Hoagland's website still incorrectly credits him as 'co-creator of the "Pioneer Plaque"'

Hoagland Controversies

In 2011, researcher Andrew Johnson created an in-depth, point-by-point denouncement of Richard Hoagland's "misappropriation" of his and Judy Wood's work in a speech given by Hoagland in Amsterdam on Sunday April 3, 2011. At various points in his nearly three hour lecture, Hoagland presented various theories, research and data originally and previously created by Wood and/or Johnson as his own, with no prior consent given.

At various times, including on the July 2, 2013 Coast to Coast AM broadcast, Hoagland has claimed that the idea to drop a feather and a hammer simultaneously on the moon was his. In actual fact, the stunt was thought up primarily by Joe Allen, with some help from Dave Scott and Jim Irwin.

On Hoagland's own digital podcast, he claimed on the November 11, 2015 to have coined the phrase, "On the internet nobody knows you're a dog." A simple check of the facts shows that Peter Steiner first published this phrase in a cartoon in the New Yorker published on July 5, 1993.

Responses by scientists

Many scientists have responded to Hoagland's claims and assertions. Professional astronomer Phil Plait described Hoagland as a pseudoscientist and his claims as ridiculous. Plait has also criticized Hoagland for having no university degree. Prof. Ralph Greenberg asserted that the logic of Hoagland's deductions from the geometry of Cydonia Mensae is flawed and says that he is not a trained scientist in any sense. The claim that the crashing of the Galileo orbiter into Jupiter caused a "mysterious black spot" on the planet has since been disputed by both NASA and Plait. There is photographic evidence that a similar "black spot" was present in imagery of Jupiter taken in 1998. A second image referenced by Plait shows a dark ring which looks similar to the spot Hoagland cited. In 1995, Malin Space Science Systems, NASA prime contractor for planetary imaging, published a paper critiquing claims that the "city" at Cydonia is artificial, the claimed mathematical relationships, and — very specifically — denying any claims about concealing questionable data from the public.

In October 1997, Hoagland received the Ig Nobel Prize for Astronomy "for identifying artificial features on the moon and on Mars, including a human face on Mars and ten-mile high buildings on the far side of the moon." The prize is a parody award given for outlandish or "trivial" contributions to science.

Publications

Books

• Hoagland, Richard C. (2002). The Monuments of Mars: A City on the Edge of Forever (5th ed.). Berkeley: Frog, Ltd. ISBN 978-1-58394-054-9.
• Hoagland, Richard C.; Bara, Mike (2009). Dark Mission: The Secret History of NASA, Revised and Expanded Edition. Port Townsend: Feral House. ISBN 978-1-932595-48-2.
• Hoagland, Richard C. (2015). Grossinger, Richard (ed.). New Horizon ... for a Lost Horizon, chapter in : Pluto: New Horizons for a Lost Horizon. North Atlantic Books. p. 312. ISBN 978-1583948972.

Contributions, introductions, forewords

• Hoagland, Richard C.; Bova, Ben (May 1977). "The origin of the solar system". In Bova, Ben; Bell, Trudy E. (eds.). Closeup: new worlds. Chapter by Richard C. Hoagland and Ben Bova. New York: St. Martin's Press. Bibcode:1977cnw..book.....B. ISBN 978-0-312-14490-6.
• Haas, George J.; Saunders, William R. (2005). The Cydonia Codex: Reflections from Mars. Forewords by Mark J. Carlotto and Richard C. Hoagland. ISBN 978-1-58394-121-8.
• NASA (1972). "The Moon". In Hoagland, Richard C. (ed.). NASA Apollo Spacecraft Lunar Excursion Module News Reference. Chapter by Richard C. Hoagland. Periscope Film LLC (published September 2011). ISBN 978-1-937684-98-3.

 

Videos

Hoagland, Richard C. (Author (with NASA Lewis Research Center)) (1990). Monuments of Mars: City on the Edge of Forever (VHS tape). Cleveland, OH: NASA Lewis Research Center. OCLC 23350482.

Hoagland, Richard C. (Executive Producer, Writer (with Geline, Robert J.)) (1992). The Monuments of Mars: A Terrestrial Connection (VHS tape). New York: BC Video Inc. OCLC 41520112.

Hoagland, Richard C. (1996). Hoagland's Mars, Vol. 1, The NASA-Cydonia Briefings (VHS tape). Venice, CA: UFO Central Home Video. OCLC 41559991. Short version, revised and updated

Hoagland, Richard C. (2008). The Hypoerdimensional Election of Barak Obama and 2012 (DVD). The Enterprise Mission.

Hoagland, Richard C. (Disk 1: "The Gods of Cydonia: The Case for Ancient Artificial Structures in the Solar System") (2005). God, Man and ET: The Question of Other Worlds in Science, Theology, and Mythology (DVD). Venice, CA: Knowledge 2020 Media. OCLC 58528205.

Cydonia (Mars) "Face_on_Mars"

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Cydonia_(Mars)#%22Face_on_Mars%22

Coordinates: 40.74°N 9.46°W

Small part of the Cydonia region, taken by the Viking 1 orbiter and released by NASA/JPL on July 25, 1976

 

Cydonia (/sɪˈdoʊniə/, /saɪˈdoʊniə/) is a region on the planet Mars that has attracted both scientific and popular interest. The name originally referred to the albedo feature (distinctively coloured area) that was visible from Earthbound telescopes. The area borders plains of Acidalia Planitia and the Arabia Terra highlands. The area includes the regions: "Cydonia Mensae", an area of flat-topped mesa-like features, "Cydonia Colles", a region of small hills or knobs, and "Cydonia Labyrinthus", a complex of intersecting valleys. As with other albedo features on Mars, the name Cydonia was drawn from classical antiquity, in this case from Cydonia or Kydonia (/sɪˈdoʊniə/; Ancient Greek: Κυδωνία; Latin: Cydonia), a historic polis (city state) on the island of Crete. Cydonia contains the "Face on Mars", located about halfway between Arandas Crater and Bamberg Crater.

Location

Cydonia lies in the planet's northern hemisphere in a transitional zone between the heavily cratered regions to the south and relatively smooth plains to the north. Some planetologists believe that the northern plains may once have been ocean beds, and that Cydonia may once have been a coastal zone. It is in the Mare Acidalium quadrangle. 

Picture of the Cydonia region taken in 2006 by The European Space Agency's satellite Mars Express.

"Face on Mars"

Cropped version of the original batch-processed image (#035A72) of the "Face on Mars". The black dots that give the image a speckled appearance are data errors (salt-and-pepper noise).

 

1976 Viking Orbiter image (left, image #070A13) compared with the 2001 Mars Global Surveyor image (right). The "Face" is 1.5 km across in size.

 

Cydonia was first imaged in detail by the Viking 1 and Viking 2 orbiters. Eighteen images of the Cydonia region were taken by the orbiters, of which seven have resolutions better than 250 m/pixel (820 ft/pixel). The other eleven images have resolutions that are worse than 550 m/pixel (1800 ft/pixel) and are of limited use for studying surface features. Of the seven good images, the lighting and time at which two pairs of images were taken are so close as to reduce the number to five distinct images. The Mission to Mars: Viking Orbiter Images of Mars CD-ROM set image numbers for these are: 035A72 (VO-1010), 070A13 (VO-1011), 561A25 (VO-1021), 673B54 & 673B56 (VO-1063), and 753A33 & 753A34 (VO-1028).

In one of the images taken by Viking 1 on July 25, 1976, a two-kilometre-long (1.2 mi) Cydonian mesa, situated at 40.75° north latitude and 9.46° west longitude, had the appearance of a humanoid face. When the image was originally acquired, Viking chief scientist Gerry Soffen dismissed the "Face on Mars" in image 035A72 as a "trick of light and shadow". However, a second image, 070A13, also shows the "face", and was acquired 35 Viking orbits later at a different sun-angle from the 035A72 image. This latter discovery was made independently by Vincent DiPietro and Gregory Molenaar, two computer engineers at NASA's Goddard Space Flight Center. DiPietro and Molenaar discovered the two misfiled images, Viking frames 035A72 and 070A13, while searching through NASA archives. The resolution of these images was of about 50 m/pixel.

Later imagery

More than 20 years after the Viking 1 images were taken, a succession of spacecraft visited Mars and made new observations of the Cydonia region. These spacecraft have included NASA's Mars Global Surveyor (1997–2006) and Mars Reconnaissance Orbiter (2006–), and the European Space Agency's Mars Express probe (2003–). In contrast to the relatively low resolution of the Viking images of Cydonia, these new platforms afford much improved resolution. For instance, the Mars Express images are at a resolution of 14 m/pixel (46 ft/pixel) or better. By combining data from the High Resolution Stereo Camera (HRSC) on the Mars Express probe and the Mars Orbiter Camera (MOC) on board NASA's Mars Global Surveyor it has been possible to create a three-dimensional representation of the "Face on Mars".

Mars Reconnaissance Orbiter image by its HiRISE camera of the "Face on Mars". Viking Orbiter image inset in bottom right corner.

 

Mars Global Surveyor image (MOC camera) of the same feature.

 

One of many formations in Cydonia, this one is sometimes called the "D & M pyramid".

 

Since it was originally first imaged, the face has been accepted by scientists as an optical illusion, an example of the psychological phenomenon of pareidolia. After analysis of the higher resolution Mars Global Surveyor data NASA stated that "a detailed analysis of multiple images of this feature reveals a natural looking Martian hill whose illusory face-like appearance depends on the viewing angle and angle of illumination". Similar optical illusions can be found in the geology of Earth; examples include the Old Man of the Mountain, the Romanian Sphinx, Giewont, the Pedra da Gávea, the Old Man of Hoy, Stac Levenish, Sleeping Ute, and the Badlands Guardian.

Speculation

The Cydonia facial pareidolia inspired individuals and organizations interested in extraterrestrial intelligence and visitations to Earth, and the images were published in this context in 1977. Some commentators, most notably Richard C. Hoagland, believe the "Face on Mars" to be evidence of a long-lost Martian civilization along with other features they believe are present, such as apparent pyramids, which they argue are part of a ruined city.

While accepting the "face" as a subject for scientific study, astronomer Carl Sagan criticized much of the speculation concerning it in the chapter "The Man in the Moon and the Face on Mars" in his 1995 book The Demon-Haunted World. The shape-from-shading work by Dr. Mark J. Carlotto was used by Sagan in a chapter of his famous Cosmos series. In 1998 a news article about the "Space Face" quoted a scientist talking about deciphering "intelligent design" in nature. A cutting of this was used by Charles Thaxton as an overhead visual for a lecture at Princeton, in his first public use of the term "intelligent design" as a substitute for creation science.

The "face" is also a common topic among skeptics groups, who use it as an example of credulity. They point out that there are other faces on Mars but these do not elicit the same level of study. One example is the Galle Crater, which takes the form of a smiley, while others resemble Kermit the Frog or other celebrities. On this latter similarity, Discover magazine's "Skeptical Eye" column ridiculed Hoagland's claims, asking if he believed the aliens were fans of Sesame Street.

In popular culture

As a result of the speculation concerning their artificial origins, Cydonia and the "Face on Mars" appear frequently in popular culture, including feature films, television series, video games, comic books, and even popular music. For example: films featuring the structures include Mission to Mars (2000); TV series include The X-Files ("Space", 1993), Invader Zim ("Battle of the Planets", 2002), Futurama ("Where the Buggalo Roam", 2002), Phineas and Ferb ("Unfair Science Fair", 2009); video games include Zak McKracken (1988), Final Fantasy IV (1991), Ultima Martian Dreams (1991), X-COM: UFO Defense (1993), SWIV 3D (1996), Red Faction: Guerrilla (2009), Kerbal Space Program (2015), Call of Duty: Infinite Warfare (2016); comic books include Martian Manhunter (#1, 1998); and music includes Cydonia from the album Implant by Eat Static (1994), Telemetry of a Fallen Angel by The Crüxshadows (1995), Cydonia by Crimson Glory (1999), "Knights of Cydonia" by Muse (2006) and Hunting & Gathering (Cydonia) by Sunn O))) (2009).

In 1958, almost two decades prior to the first images of the Face from the Viking probes, the comic book artist Jack Kirby wrote a story entitled "The Face on Mars" for Harvey Comics (Race for the Moon Number 2, September 1958), in which a large face (oriented vertically rather than horizontally) served as a monument to an extinct humanoid race from Mars.