Space Science Research
Part of Public Response to President’s Space Exploration Initiative
In 1991, I was one of about 1000 individual respondents nationwide to the Outreach Program, processed by NASA and the RAND Corporation, of the Space Exploration Initiative, announced in 1989 by President George H. W. Bush.
The ultimate goal of the initiative was to put Americans back on the Moon and eventually on Mars. Along the way, various other objectives were planned, for this ambitious, post–Cold War national mission:
“National Space Visions”
- Increase our knowledge of the solar system and beyond.
- Rejuvenate interest in science and engineering.
- Refocus U.S. position in world leadership (from military to economic and scientific).
- Develop technology with terrestrial application.
- Facilitate further space exploration and commercialization.
- Boost the U.S. economy.
The purpose of the Outreach Program was to "cast a wide net" for innovative ideas throughout the country. Those who chose to respond to the direct mailings, mass advertising, and other outreach methods included everyone from members of the American Institute of Aeronautics and Astronautics to everyday citizens, including some schoolkids who were just space buffs. All of the ideas submitted, in a strictly designated format, were systematically catalogued, reviewed, and ultimately integrated by a Synthesis Group, composed of military, other government, academic, and industry experts. The final report, America at the Threshold, was presented to the president in May of 1991.
Having been a vocal supporter of the space program all my life, I could not pass up this opportunity to submit a few ideas I had read or heard about over the years, in the mass media, scientific publications, scholarly presentations (as by the nearby Jet Propulsion Laboratory), or university discussion groups. Here are links to my submissions, with quotes or other considerations about the topics from the report to the president:
- High Orbit Solar Power Satellites: “Solar flux in free space or on the lunar surface can be collected and the energy transmitted to ground-based receivers. This concept has the potential of providing globally distributed electricity. Extensive studies of these concepts by NASA and the Department of Energy validate the technical feasibility. Economic benefits have been shown to accrue only if the space segment (collectors, transmitters, structure) are constructed and transported using materials already available in space. Such production would have minimal impact on the terrestrial environment, utilizing a benign power-beaming system.”
- Centrifugal Force for Artificial Gravity: “The existing knowledge base for deconditioning from long term zero gravity exposure ... indicate[s] that with appropriate countermeasures, a crew can be maintained in satisfactory condition throughout long duration flights; therefore, artificial gravity is not incorporated in the four architectures.”
- Cesium and Rubidium in Ion-Propulsion Systems: Xenon or argon were shown to be better candidates for nuclear electric thrusters, as for Moon and Mars cargo missions; but magnetoplasmadynamic engines were apparently even better candidates in the long run.
High Orbit Solar Power Satellites
BRIEF DESCRIPTION (Ref. Remarks published in the Los Angeles Times, on March 7, 1989 by Gerard K. O’Neill, professor emeritus of physics at Princeton University, founder of the Geostar Satellite Corp., and appointee to the National Commission on Space): “A fully acceptable system for generating energy must add little to the Earth’s heat load, burn no fossil fuels and avoid nuclear fission or fusion. There is only one method that satisfies all these conditions — the conversion of solar energy to electric power in high orbit, where sunlight is intense and continuous.”
PAYOFF OR VALUE: “To meet all the energy needs of 2039, the market would be more than $6 trillion a year annually (in today’s dollars), larger than America’s present gross national product. We as a nation cannot afford to be left out of a commercial program with so huge an export market. Above all, we who live in the biosphere cannot let it die.” Fossil fuels can remain as profitable industrial sources of raw organic compounds for materials instead of energy.
ENABLING TECHNOLOGIES OR SYSTEMS: “Twenty years of study and experiments confirm that power in high orbit can be sent efficiently to Earth as low-density radio waves. Antennas in fenced-off regions can transform the radio waves to ordinary electricity.
“A decade of study and experimentation by government agencies and private foundations confirms that satellite solar power is environmentally benign. It can compete economically with coal-fired and nuclear-power plants if we can avoid having to haul materials out of the Earth’s strong gravity. Materials for the power satellites — metals, silicon, and oxygen — can come from the moon, whose gravitational grip is less than a twentieth of the Earth’s. Those materials are the most abundant elements of the lunar surface and can be mined using known space technology.”
RELATION TO MAJOR MISSION OBJECTIVES: “The Soviet Union and Japan are particularly aggressive now in working toward satellite solar power. A commercial multination program, modeled on the successful Intelsat and Inmarsat consortia that provide satellite communications, would earn revenues of $250 billion a year, satisfying today’s needs for new electric generators” and allowing the space program to more than pay for itself. Also, international cooperation would be important in further space exploitation and exploration, in terms of both spreading financial burdens and diminishing security risks in this ultimate “high ground.”
Centrifugal Force for Artificial Gravity
BRIEF DESCRIPTION: “Centrifugal” force (the equal but opposite force to the “centripetal” force that acts on a body to keep it in circular motion and that is directed to the center of rotation) can be produced by a cylindrical design of space vehicle, to supply medically beneficial artificial gravity on the inside wall of the vehicle.
PAYOFF OR VALUE: Providing artificial gravity, via centrifugal force, will prove invaluable in alleviating the crew of the physiological disorders and psychological disorientations that commonly develop during long periods of weightlessness.
Additionally, in order to produce centrifugal force, the ship will rotate around its longitudinal axis as it travels forward: Gyroscopic effects, akin to the effects of gun-barrel rifling on bullets, may help flight stability.
PERFORMANCE CHARACTERISTICS: The basic design of the ship, or at least of the crew’s living quarters, will need to be cylindrical; and side thrusters will need to be provided, in order to produce and, as need be, correct the uniform rate of rotation and, thus, centrifugal force.
As an example, if the cylindrical ship had an internal radius of 25 meters, it would need to rotate around its axis once every 10 seconds in order to create a centripetal force on the crew that would be felt as a centrifugal force on the wall under their feet equal to the force of gravity on their mass (regardless of what it is) upon the surface of the Earth.
Although the inside wall of the ship will, thus, serve as an artificial landscape, the central “core” of the ship will remain in a low-gravity condition, facilitating the “weightless” storage and lifting of massive items.
RELATION TO MAJOR MISSION OBJECTIVES: Overcoming the deleterious physiological and psychological effects of weightlessness can better make long journeys into space by human beings feasible.
Cesium and Rubidium in Ion-Propulsion Engines
BRIEF DESCRIPTION: Because of their ease of oxidation and natural occurrence in and near the United States, the alkali metals cesium and rubidium are prime candidates for our use in ion-propulsion and other systems in space.
PERFORMANCE CHARACTERISTICS (Ref. 55th Edition of the Handbook of Chemistry and Physics): Cesium (atomic number 55) occurs in such minerals as “lepidolite” and “pollucite”: At Bernic Lake, Manitoba, deposits contain perhaps 300,000 tons of pollucite, averaging twenty percent cesium. The price in 1974 of a pound of purified cesium was $100 to $150. Cesium is a silvery-white, soft, ductile, and liquid metal at room temperature. Cesium is the most electropositive and most alkaline element, reacting explosively with cold water and at some temperatures even reacting with ice; and cesium hydroxide is the strongest base known, attacking glass. In ion-propulsion systems in space — NOT usable in the Earth’s atmosphere — one pound of cesium theoretically will propel a vehicle 140 times as far as the burning of the same amount of any known liquid or solid. Cesium can also be used in photoelectric cells, in atomic clocks, as a “getter” in radio tubes, and as a catalyst in the hydrogenation of certain organic compounds.
Rubidium (atomic number 37) is perhaps the sixteenth most abundant element in the Earth’s crust, occurring in “pollucite” (as with cesium in Bernic Lake — above), “carnallite,” “lepidolite,” “leucite,” and “zinnwaldite”; and potassium minerals, such as those found at Searles Lake, California, and potassium chloride recovered from brines in Michigan also contain the element and serve as commercial sources. In 1974 a pound of prepared rubidium cost approximately $300. Rubidium is a soft, silvery-white metal that can be liquid at room temperature. It is the second most electropositive and alkaline element, igniting spontaneously in air and reacting violently in water — rubidium must be kept under a dry mineral oil or in a vacuum or inert atmosphere. Ordinary rubidium is sufficiently radioactive to expose a photographic film in about thirty to sixty days. Because rubidium can be easily ionized, it can be considered for use in ion engines for space vehicles, although cesium (above) is somewhat more efficient for this purpose. Rubidium can also be used as a working fluid for vapor turbines, for use in a thermoelectric generator using the “magnetohydrodynamic” principle, as a “getter” in vacuum tubes, and as a photocell component; and a rubidium compound with silver and iodine has the highest room conductivity of any known ionic crystal, suggesting use as in thin film batteries.