Earthrise

ON THE COVER:

earthrise

When the leadership of Apollo reached for the moon, it raised a new set of engineering issues for us back here at home.

By Aloysius I. Reisz

On Dec. 21, 1968, men left Earth's orbit for the first time and journeyed to the moon. Apollo 8 circled the moon 10 times, took pictures, and brought them home. We were in awe during the winter holidays of 1968 of the men traveling to and around the moon.

Earth eyes first saw their planet from afar, with its fragile blue atmosphere and swaddling white clouds. It was an image that forever changed our perception of this planet we inhabit. Many of us were also endowed with a new sense of awareness of our Earth and its uniqueness in our solar system and, for all we know, in the universe.

The Apollo program was a remarkable feat of engineering and a heroic human endeavor. It proved that mankind is not bound to Earth. The Apollo missions endowed us with a new sense of confidence in our intelligence and an awareness of our existence. Above all, the view of the graceful Earth from the moon inspired us to engineer better systems for our home planet.

The program was managed by engineers who were undaunted by seemingly impossible challenges. They planned and then developed a launch vehicle that propelled a 100,000-pound payload—including three astronauts—to velocities of 25,000 mph to escape Earth's orbit.

The engineering managers who developed the Saturn V envisioned what had to be accomplished and set about doing it. They were unafraid of applying scientific principles and were confident in their engineering. Perhaps just as important, they communicated effectively with United States government leaders and with the American people, thereby assuring popular support for their mission to land men on the moon.

To achieve Apollo program tasks, they led us in an expansion of science and technology that is still propagating.

To get more power per upper stage fuel weight, liquid hydrogen, then a difficult fuel to control, required new fuel storage and delivery systems. Integrated circuits, then in research laboratories, were developed and used to reduce Apollo launch vehicle and spacecraft electrical packaging weight. Not only was vehicle weight reduced, but in putting the electronic circuits on silicon chips a new age of electronics began.

Engineers used slide rules when the Apollo program began. By the end of the program, handheld calculators were on the market and slide rules were history.

Many people first became aware of fuel cells and solar photovoltaics when they were used to assist in powering the Apollo spacecraft because other power sources were too heavy.

Lasers were brought out of the laboratory to make precise measurements in space. Astronauts left a mirror on the moon so that an Earth laser could measure the precise distance. We have since learned that the moon is moving away from Earth at a rate of 1 1/2 inches per year.

Apollo's engineering leaders showed us how to envision solutions to achieve objectives in a required time. They left us with lessons in engineering leadership. Before the lessons fade, they need to be recalled and used to achieve a greater challenge as we enter this new millennium.

Earth is a rare planet that coalesced from condensing clouds of molecular dust and gas at a distance from its star conducive to the existence of water. Over the eons, Earth evolved into a water planet with a nitrogen-oxygen atmosphere that scatters the blue from solar light into an atmospheric radiance. Sunlight reaching Earth stimulates photosynthesis in organic green flora. Through the ages, Earth attained an environment that supports the life we know.

Life on Earth faces an eternal struggle for survival. Existence has evolved with humans being the highest order, gifted by nature in that only we have the intelligence to plan our way of living, our future, and our destiny. Since the early industrial age of the 19th century, hydrocarbon fossil fuels have been combusted to power the rapid advances to our modern life systems. Entering this third millennium, it is evident that anthropogenic, or human-caused, pollution are poisoning Earth's ecology and depleting her natural resources. Continuing the course of 20th-century life will lead to the death of Earth.

The Way We Are

During each Earth revolution, we human inhabitants generate 1.1 quadrillion Btu of energy to maintain our way of life. In doing so, we consume 13 million tons of coal, 75 million barrels of oil, and 225 billion cubic feet of natural gas. On each revolution we churn 20 tons of CO₂, 800 pounds of SO₂, 2 tons of nitrogen oxides, 2 tons of methane, and 4,000 tons of particulate matter into Earth's blue atmosphere. Earth's lands and waters are likewise being polluted.

Since the industrial age began, we have engineered a comfort of human life where we are cooled in summers, drive automobiles everywhere convenient, board airliners for passage to anywhere in hours, and have powerful computers with Internet connections. We have developed an infrastructure that wheels power across continents with grids of tower- and pole-supported electric lines.

Our infrastructures of electrical transmission lines, highways, and fuel pipelines are never enough to meet our increasing demand. Brownouts experienced in summer months renew the demand for more electricity generating plants and transmission lines. Consumer fuel shortages generate demands for more gas and oil drilling, refinery capacity, and oil and gas pipelines.

Planet Earth is strangling with the infrastructure systems we are building. We are choking Earth's natural regenerative system. The ozone layer in the stratosphere that protects life on Earth from detrimental solar radiation is diminishing, it is thought, because chlorofluorocarbon refrigerant gases seep into the atmosphere.

Many scientists maintain that a greenhouse effect caused by industry-generated CO₂ accumulating in the atmosphere traps heat, and causes global warming and alteration of weather patterns that adversely affect food supplies. The diminution of Earth's green forests is reducing the regeneration of oxygen to the atmosphere, while atmospheric carbon dioxide is said to be increasing. Flora and fauna species that have evolved with us are disappearing.

Green engineering is developing clean energy and life systems that conserve Earth's ecology. Clean energy can be obtained from the first elements of the universe, light and hydrogen. Energy from nuclear fusion leaves no hydrocarbon pollutants. Clean energy is also obtained from wind, celestial heat, and biomass, hydrocarbon matter before heavier Earth elements are entrained.

To preserve Earth's ecology, products and systems must be engineered by people who are conscious of the effects of resources consumed, manufacturing, life cycle use, residuals, recycling, and disposal.

Deep in the sun 92 million miles away, hydrogen fuses to form helium and causes energy to be radiated into space. Solar radiation falls on Earth, to the tune of 1,400 watts per square meter.

In the early 1970s, Saturn rockets boosted Skylab modules into orbit to conduct solar and space experiments. Skylab had a pair of 3,000-watt photovoltaic arrays that provided half of the mission's electricity. The Skylab solar energy system left room for more research payload weight.

As seen from the lunar module, the Apollo 16 mission's command module, and its lifeline back to Earth, orbited above an inhospitable moonscape.

The energy crisis that followed the Apollo program in the 1970s caused engineers to examine solar energy as an alternative to fossil fuel energy. Solar and wind energy systems were demonstrated to be a practical and clean means of supplying energy in lieu of fossil fuels.

When fuel oil was curtailed at a soy processing plant at Decatur, Ala., in 1976, my firm, Reisz Engineering, conceived and helped develop a large-scale solar energy system used in processing soybeans into soy oil and high-protein feedstuff. This system reduced the fuel oil required for soy processing. I presented a technical paper, 79-WA/Sol-32, on this project at the ASME Winter Annual Meeting in 1979.

When oil prices dropped, so did the use of solar energy. Solar energy is destined for more extensive use because of new necessities for clean energy. Green architecture will incorporate active and passive solar energy and light features into building systems to reduce artificial heating, cooling, and lighting requirements for comfortable living.

In forming Earth, matter was compressed and the resulting body has gravity. Heavier elements are drawn toward Earth's center. The center of the Earth has a molten iron core that radiates heat outward.

For any region on Earth, at any particular depth, the temperature remains nearly constant the year around. So does the ground water. In Kentucky, for example, that temperature is approximately 58°F at depths from 3 to 300 feet. In central Alabama, it is 60°F. For heating and cooling buildings, it is this constant temperature that engineers can use.

In summer, the building heat is dissipated into the ground to maintain a comfortable 70°F inside. In winter, the heat transport medium brings in 60° water, which is raised only about 10 degrees, rather than heating wintry outside air from a temperature of perhaps 35°.

Geothermal energy is clean and reliable. Geothermal mechanical heat pumps move heat from the ground into buildings in winter and from buildings into the ground in summer. Pump electricity is used only to transport the heat. Geothermal heat pumps deliver three to four times more energy than they consume, and are cheaper to operate than conventional heating and cooling systems.

The use of geothermal systems reduces the quantity of fossil fuels combusted for heating and cooling, and therefore reduces air pollutants. An engineering study that my firm conducted for a new Mercedes-Benz plant facility under construction near Vance, Ala., determined that the 300-ton geothermal heat pump system will annually reduce CO₂ emissions by 540,000 pounds, SO₂ emissions by 4,520 pounds, and nitrogen oxides by 1,740 pounds compared with a 300-ton air-cooled chiller with cooling tower that would otherwise have been installed.

On certain areas of Earth, steam exists below the surface that can be harnessed to produce electricity.

Fuels for the Future

The Saturn V's first stage used kerosene as fuel, burning with oxygen. The kerosene-liquid oxygen first stage propellant generated 265 seconds of specific impulse. Specific impulse is the thrust force delivered per mass flow rate of propellant. It is the length of time that one pound of propellant will generate one pound of thrust.

To rise into the upper atmosphere with lighter propellant loads, the upper stage rocket motors burned liquid hydrogen, a relatively new rocket fuel at that time, with liquid oxygen. The liquid hydrogen rocket generated thrust with a specific impulse of 425 seconds. It was the powerful light hydrogen fuel that made the journey to the moon possible.

Combusting the 1,415,257 pounds of kerosene in the first stage during the (2 1/2) minutes of ignition produced 7.5 million pounds of thrust and propelled the vehicle to an altitude of 36 miles at 6,000 mph. In that time, the first stage also produced 240 tons of carbon monoxide, 836 pounds of sulfur dioxide, 1,398 pounds of nitrogen oxides, 1,238 pounds of particulate matter, and smaller amounts of other pollutants.

The hydrogen-fueled second stage took the spacecraft to a 108-mile altitude Earth orbit. The third rocket stage, also hydrogen fueled, in two firings put Apollo first in position and then on course to the moon at 24,900 mph. The hydrogen-fueled second and third stages of the Saturn V rocket produced only water vapor and clean thrust.

Hydrogen was the first substance of creation and is the simplest. It is the most abundant element in the cosmos and on Earth. Hydrogen doesn't exist as a pure gas on Earth because it so readily combines with other elements, such as oxygen to become water or with carbon to form hydrocarbons. Hydrogen can be separated from these elements to become clean renewable fuel.

Hydrogen is commonly produced today from hydrocarbon fossil fuels such as coal and methane. It is also produced from biomass alcohols. Solar photovoltaic systems can produce hydrogen from water by electrolysis with no pollutant by-product.

Hydrogen can fuel stationary and mobile fuel cells. The anode of the fuel cell gives hydrogen a negative charge, allowing the cell electrolyte to take the electron and generate electricity. The electron then recombines with hydrogen at the cathode and with oxygen present forms water.

In a magnetoplasma-dynamic engine, hydro-gen or lithium is in-jected between coaxial electrodes and ionized. The current produces a magnetic field, causing a Lorentz (j x B) force on the plasma.

Hydrogen can also fuel internal combustion engines to generate power. When hydrogen storage and transportation infrastructures are developed, we will be free of the coal-gas-nuclear generated electricity power grids and from gasoline and diesel combustion-powered vehicles.

When plants decay and are absorbed into Earth's soil, they begin a process of absorbing heavier elements on the way to becoming fossilized hydrocarbon fuels. However, when plant matter, called biomass, is processed into fuels before being absorbed by the soil, combustion yields neglible amounts of pollutants. Biofuels are made from plant matter and from cellulosic waste. Methane, ethanol, and methanol are common biofuels.

The heating value of alcohol fuels is close to that of petroleum refined fuels. Today, biofuels cost more than fossil fuels. This would not be so if the cost of cleaning the pollution out of the air from burning cheaper fossil fuels were factored in.
Alcohol currently has the advantage over pure hydrogen fuels, since it can be transported and stored in the infrastructures developed for petroleum. Methanol and ethanol can be used directly in fuel cells or reformed to produce hydrogen for fuel cells.

Landfills can be tapped for methane to fuel community or industrial processes. Biomass also can be gasified to produce a synthetic gas primarily of hydrogen and carbon monoxide. This syngas can be used for industrial processes, or its hydrogen can be recovered for use in fuel cells or as engine fuel.

Back to the Dawn of Creation

Before there were stars, light radiated in the universe. In Genesis, creation begins with light. Light is energy in the form of electromagnetic waves that our eyes can sense. Light has no volume, mass, or charge. Light behaves as a wave as it moves through space and as a particle when it encounters matter. Photons can transmit information and ideas around our planet at the speed of light. Photonics may replace electronics early in this century.

Certain frequencies of electromagnetic waves, in the form of radio waves and lasers, can be used to manipulate the atomic structure of gases and plasma in order to release clean energy. Light at certain frequencies can induce fusion of light elements to heavier elements and clean energy.

Skylab, shown here in a photo taken by the craft's departing third crew, raised the profile of solar power in the public imagination. Photo-voltaic panels powered Skylab's instruments and took up less space than conventional electricity sources.

Photo provided by NASA.

Fusion of deuterium and tritium, isotopes of hydrogen, yields energy and helium. For fusion to occur, the hydrogen isotopes must be brought to the fourth state of matter, plasma, and confined. In stars, gravity confines and controls plasma; on Earth, enormous magnetic fields must be generated to confine plasma for fusion. Perfecting the production of energy by fusion is an engineering challenge for the 21st century that promises cheap, abundant, clean electricity.

Again, technical solutions are coming from aerospace engineering. NASA and space agencies in Germany, Russia, and Japan are developing magnetoplasmadynamic rockets that accelerate charged particles using magnetic fields. Hydrogen, lithium, or argon gas is channeled into a cone-shaped anode with a cathode axial rod in the center. Voltage between the electrodes ionizes the propellant, causing electric current to flow along the axial cathode rod creating a circular magnetic field. This magnetic field interacts with the gas to accelerate gas particles, thereby creating rocket thrust.

NASA is developing a magnetoplasma rocket that uses radio waves to ionize the hydrogen and heat it to 10 millionûF. A magnetic field confines the gas and provides a variable choke at the rocket throat, allowing variable exhaust velocity, thrust, and specific impulse. Deep space travel is possible with this high-specific-impulse, low-thrust rocket.

Another deep space transportation method of the future is a magnetic particle sail for spacecraft that will ride a light or radio beam at a specific frequency from Earth, or perhaps sunlight, to Mars and beyond. Back on Earth, it is conceivable to generate clean, cheap power with ionized hydrogen atoms in magnetic fields using the technology of magnetoplasma engines.

Our challenge is to engineer systems that will transform our human ways so as to preserve life on Earth. Green engineering plans and develops clean energy and life systems that preserve, rather than consume, Earth's resources.

Beginning this new millennium the way we are, a society whose economy and lifelines depend on Earth-polluting fossil fuels, this may seem an impossible challenge. In 1964, during the midst of the development of the Saturn V rocket, Wernher von Braun wrote: "How far can man go in space? Where will his search for eternal truth about himself and the universe end? Man's mind and will alone can limit his advance toward fulfilling his destiny."

Our minds and wills must be used to preserve life on Earth so that we will live to learn more of the truth about ourselves and the universe. Engineering is the application of human intelligence for the betterment of life. Engineers must not be satisfied with a role of merely making rote calculations. Rather, we must also provide vision and leadership in developing and implementing new technologies that will allow perpetual use of the Earth and its resources.

This is a far greater challenge than our journey to the Moon and one that will endure longer. We can find wisdom in the engineering lessons learned during the Apollo missions, and go forward in achieving our quest of sustaining life on Earth into the far future so as to fulfill man's destiny in the universe.

Al Reisz, a Fellow of ASME, worked as a propulsion engineer on the development of the Saturn V rocket during the Apollo program. The Saturn V was developed under the direction of Wernher von Braun.