DrDonald Rapp

Brief Summary

I have 64 years of post-doctoral experience. I am a true generalist. I am about 50% scientist and 50% engineer. I have worked on an extremely wide variety of technical problems over the years and I have broad knowledge of things technical. I have a solid grounding in chemistry and physics and did fundamental work in these sciences for many years. I developed semi-classical quantum mechanical modeling of atomic collisions. I made fundamental measurements of ionization cross sections that are still used today, 64 years later. In the second half of my career I worked on more applied problems, particularly in space technology and space mission design. I am an expert in requirements, architectures and transportation systems for space missions, with particular emphasis on impact of in situ resource utilization, and water resources. I have surveyed the wide field of global climate change and ice ages and I am familiar with the entire literature of climatology. I am known far and wide in the NASA community for my abilities to plan, organize and lead studies of broad technical systems. My services have been often sought in writing and reviewing major proposals for space ventures. I have written and published 8 books.

From 2015 to 2023 I was a co-investigator on the Mars MOXIE Project documenting progress and analyzing various aspects of the data and operations. In that work, I produced a large number of internal reports and I co-authored five papers.

In 2022 I received the Gano Dunn award by the Cooper Union that "honors an outstanding alumnus for professional achievement."

Education

• B.S. Chemical Engineering, Cooper Union, 1955

• M.S. Chemical Engineering, Princeton, 1956

• Graduate study, California Institute of Technology, 1957

• Ph.D. Chemical Physics, University of California (Berkeley) - January, 1960

Experience

• 2015, co-I on Asteroid study for NIAC

• 2014-2023, Co-I on "MOXIE" NASA ISRU demonstration for 2020 Mars payload - consultant to MIT and JPL

• 2013, JPL Interim Employee to write MOXIE proposal

• 2010-2013, authored major works on climate change and missions to Mars

• 2008-2009 Research Professor, Viterbi School of Engineering, University of Southern California

• 2003-2009, JPL Consultant

• 1979-2002, Jet Propulsion Laboratory, Pasadena, CA; Senior Research Scientist and Division Chief Technologist, Mechanical Systems Engineering and Research Division; Retired February, 2002

• 1969-1981, University of Texas at Dallas:

  • 1981 Resigned

  • 1979-1981 On Leave of Absence while at JPL

  • 1973-1979 Full Professor of Physics and Environmental Engineering

  • 1969-1973 Associate Professor of Chemistry and Physics

• 1965-1969, Polytechnic Institute of New York: Associate Professor of Chemistry

• 1959-1965, Lockheed Palo Alto Research Laboratory: Senior Staff Scientist

AI commentary on Donald Rapp:

Part 1:

I asked AI:

Did Rapp D. Human Missions to Mars Using the Starship published in 2025 provide a better way for the first human mission to Mars?

Slightly reduced to conform to 3,000 character limit

Yes, Donald Rapp’s August 2025 paper, "Human Missions to Mars Using the Starship", published in IgMin Research, provides a simpler, safer, and arguably better architectural alternative for the very first human mission to Mars compared to standard SpaceX and NASA proposals.

By capitalizing on the massive payload capacity of SpaceX's Starship, Rapp shifts the space exploration paradigm away from strict "mass minimization". Instead, he advocates for using that extra mass to systematically lower overall mission complexity and risk.

The Core Problem with the SpaceX Plan

SpaceX's baseline "Mars Leviathan" architecture envisions a direct-return model. A massive Starship lands a crew of 12 on Mars, which eventually refuels using Martian In-Situ Resource Utilization (ISRU) to fly directly back to Earth.

Rapp notes severe bottlenecks with this plan:

The Water Mining Gamble: To produce over 1,200 tons of return propellant, the mission relies heavily on extracting massive amounts of indigenous Martian water ice.

Landing Site Restrictions: The search for accessible ice forces a landing at higher latitudes (around 40°N). This geographic constraint severely limits available solar power and introduces weak-sun winter conditions that are psychologically challenging for the crew.

Herculean Launch Cadence: Fulfilling the baseline SpaceX plan requires roughly 60 to 72 heavy-lift Super Heavy launches just to fuel multiple transit vehicles in Low Earth Orbit (LEO).

Rapp's Proposed "DRA-6" Alternative

Instead of a "colony-first" approach, Rapp proposes a targeted, scientifically focused initial mission architecture called DRA-6:

Eliminating ISRU Water Reliance: Instead of relying on unproven Martian ice mining, the DRA-6 architecture utilizes Starship's high payload capacity to bring all required water for life support and return-trip fuel straight from Earth.

Equatorial Landing Sites: Removing the reliance on northern ice deposits allows the first crew to land directly at the Martian equator. This shift yields massive advantages in solar energy availability, thermal stability, and orbital energy efficiency.

Split Vehicle Architecture: Rather than attempting to launch the gargantuan Starship directly back from the Martian surface the crew of six escapes Mars in a small capsule. This capsule then rendezvous with an Earth Return Vehicle (ERV) left waiting in Mars orbit.

Ultimately, while Rapp acknowledges that SpaceX's mass-heavy approach completely revolutionizes Mars planning, he highlights that a true first landing shouldn't gamble human lives on localized Martian mining. By bringing Earth-vetted fuel resources and using an orbital rendezvous, Rapp’s 2025 blueprint offers a much more immediate, achievable pathway to the Red Planet.

 Part 2:

I asked AI: “How influential was the work by Donald Rapp and co-workers in the early 1960s on electron impact ionization of atoms and molecules?”

The answer:

The work by Donald Rapp and his co-workers (such as Paula Englander-Golden and D.D. Briglia) in the early 1960s was immensely influential, primarily because it provided the first highly accurate, standardized absolute cross sections for electron impact ionization. Their experimental methods and data remain foundational and are still routinely referenced.

Why Their Work Was Groundbreaking

Unprecedented Accuracy: Before the mid-1960s, existing data on ionization cross sections and dissociative ionization varied wildly among different laboratories. Rapp and Englander-Golden employed an innovative total-ionization tube to measure absolute cross sections with an emphasis on rigorous consistency.

The Definitive Dataset: Their seminal papers, published in The Journal of Chemical Physics in 1965 (Total Cross Sections for Ionization and Attachment in Gases by Electron Impact. I. Positive Ionization, and Cross Sections for Dissociative Ionization of Molecules by Electron Impact), established a comprehensive, consistent set of data for the rare gases and a wide variety of molecules.

Crucial Correction Factors: By carefully analyzing the trajectories of atomic and fragment ions in electric and magnetic fields, they identified and quantified limitations in the ion-collection efficiencies of earlier instruments.

Long-Term Influence

Plasma Physics & Atmospheric Science: The 1960s sparked a surge in space exploration and earth's ionosphere studies. Because Rapp’s cross sections were so reliable, they became the required baseline input for modeling both the earth’s upper atmosphere and astrophysical phenomena.

Mass Spectrometry & Chemistry: Their data provided essential benchmarks for gas-phase chemistry and electron impact mass spectrometry, allowing researchers to understand fragmentation patterns and absolute ionization probabilities.

Standardization: Even decades later, as modern computing and advanced detection technologies emerged, subsequent studies (such as those by Wetzel et al. and Straub et al.) relied on Rapp’s original values as the standard for normalizing and verifying relative cross section measurements

Notable Recognition

• Elected Fellow of the American Physical Society, 1974

• Referee for the Journal of Chemical Physics, the Physical Review, the American Journal of Physics, the Journal of Physical Chemistry, and other journals on over 300 occasions.

• Received Exceptional Service Award from NASA October, 2002

• Associate Editor of the Mars Journal 2006 - present

• Particularly noteworthy: I wrote the "Deep Impact" and "Genesis" JPL mission proposals totaling $500 million.

• Listed in Who's Who in the West:

  • Listed in Who's Who in Frontiers of Science and Technology

  • Listed in Who's Who in America

  • Listed in Men of Achievement

  • Listed in International Who's Who of Contemporary Achievement

  • Listed in International Who's Who of Professionals

  • Listed in Personalities of the Americas

  • Listed in Who's Who in Technology Today

  • Listed in Who's Who in Technology

  • Listed in Who's Who in California

  • Listed in Who's Who of Professionals

  • Listed in Two Thousand Notable Americans

  • Listed in Dictionary of International Biography

  • Listed in Strathmore's Who's Who

Other DR websites:

Mars and Moon:

https://sites.google.com/view/marsandmoon/home

Ice Ages and Interglacials: The final understanding of ebb and flow of ice ages

https://sites.google.com/view/iceages

Impressionist Art:

https://www.love-art.com

Highlights of My Work

In the 1960s and 1970s:

• I derived and clarified the relationship between classical, semi-classical and quantum calculations of vibrational energy transfer between molecules in molecular collisions.

• I produced models for vibrational energy transfer in a variety of molecular collisions

• I developed simple models for electron transfer between atoms and ions in atomic collisions. I showed how symmetric and asymmetric charge transfer processes were related.

• I developed a set of simple approximate wave functions for the outer electron of an alkali atom, and I used these to model electron transfer in collisions of alkali atoms with alkali atoms. I also showed that they produced good estimates of first ionization potentials.

• I set up a laboratory to measure ionization processes when electron beams passed through gases, and I made fundamental measurements of cross sections for ionization of many atoms and molecules. These fundamental standards are still used today 65 years later.

• With the advent of parallel processing on computers, I created math programs to diagonalize matrices and solve differential equations.

More Recently

• I developed templates and procedures for writing proposals for major space missions at JPL and applied them to winning proposals for the Suess-Urey mission and the Deep Impact mission.

• Working as a consultant for the Mars MOXIE Project from 2014 through 2023, I provided continuing documentation of work on the Project, I provided a widely used computer model of the end-to-end system, I cataloged the test data and analyzed it, and I provided an analysis of prospects for scaling up to full-scale proportions.

• I  developed a model for ice ages over the past 2.7 million years and showed how the pacing of ice ages changed across the Mid-Pleistocene transition.

• I analyzed prospects for utilization of indigenous resources on Moon and Mars.

Donald Rapp -- Additional Background

In the 1960s and 1970s:

I developed a greater understanding of the relationship between classical, semi-classical and quantum calculations of transitions in atomic and molecular collisions, and I applied this understanding to a variety of atomic and molecular systems. A completely quantum calculation would typically be very complex in which the various particles involved would be represented by waves, that interact where they meet. A fully classical calculation treats the particles according to classical mechanics, and they follow deterministic trajectories, and exchange energy in differential amounts, not bound by quantum mechanics. In a semi-classical calculation, the interacting atoms or molecules are assumed to move through space along classical deterministic trajectories, and in so doing, apply forces to one another. The internal properties of the atoms or molecules are treated properly as quantum particles with quantized energy levels. The forces applied by the deterministic classical external motion induce transitions between the quantized internal energy levels.

A diatomic molecule can be approximated as a harmonic oscillator (two masses connected by a spring) with evenly spaced, quantized energy levels. When such an oscillator is hit by an impacting atom, it can drive the oscillator into an excited state by transferring kinetic energy from the atom to the oscillator. I used the semi-classical method to investigate a wide variety of such collisions. I showed that in the classical approximation, a small amount of energy (e) is transferred to the (non-quantized) classical oscillator in every single collision. In the semi-classical model, a full quantum (E) is transferred to the oscillator in only a small fraction (f) of collisions. I showed that e = (E) (f) so that, when averaged over many collisions, the net energy transferred is the same.

Semi-classical models for atomic and molecular collisions existed before I came along, but I clarified aspects of such models, and applied them to a number of specific cases. These are documented in a dozen paper published in peer-reviewed journals.

I also investigated electron transfer between atoms in atomic collisions of ions with atoms. If a charged ion (A+) passes near a neutral atom (B), it can steal an electron, ending up with (A) + (B+). In the model, a high velocity A+ ion passes near a stationary B atom, along a classical trajectory. An outer electron on the B atom is attracted to both its nucleus (B+) as well as the net charge on the A+ ion. There is a probability that the electron, originally on (B), will “jump” to A+, ending up with (A) + (B+). A special case occurs when A and B are the same atom. This is called “resonant charge transfer” because there is no energy required for the electron jump. The beginning and ending energy levels are the same. When A and B are different atoms (asymmetric charge transfer), there is usually a difference in the energies of the initial and final states. A very special case can occur where A and B are different, but their energies are nearly the same; this is called “accidentally resonant”.

At the time that I worked in this field, each case of charge transfer between atoms was viewed individually, and there was no overall model that encompassed many such processes. Furthermore, resonant charge transfer was treated as a very different process than non-resonant charge transfer. In a landmark paper written in 1962, I developed a model that expressed the cross section for charge transfer of resonant system vs. collision velocity as a function of the first ionization potential of the atoms involved. For asymmetric charge transfer, I developed a model that showed it acted like symmetric charge transfer at high enough collision velocities, but the cross section decreased sharply below a certain threshold velocity. The comparison of this model with data available at that time was good.

In subsequent years, I carried out more sophisticated models of specific charge transfer processes. Of particular interest was the use of pseudo-potentials for the alkali atoms in which the outer electron is modeled quantum mechanically to move in the electric field represented by the nucleus plus an electron cloud of the inner electrons. With such pseudo-potentials assigned to each alkali atoms, charge transfer between various alkali atoms can be modeled as transfer of a single outer electron from one atom to another where the electric fields of the alkali atoms are the pseudo-potentials. This work was done in the early 1970s.

One of the most important, and most fundamental processes in plasma physics is electron impact on an atom or molecule, knocking out one or more electrons from the atom, leaving the atom ionized. Back in the 1930s, some astute scientists made measurements of this ionization process for a number of atoms and molecules. In the 1960s, I decided to reinvestigate ionization of atoms and molecules by electron impact using more modern technology. Our team made important basic measurements of the energy dependence of cross sections by electron impact that are still used today, including ionization and electron attachment by electron impact on atoms and molecules.

As a Professor of Physics, I decided to write textbooks on quantum mechanics and statistical mechanics in 1971 and 1972. These books went out of print about 20 years later, but I reissued them as self-published in 2012-2013.

The JPL Years: 1979-2002:

In 1979, I joined JPL where I no longer did research but worked in technology management. During my time at JPL I carried out a number of studies; A few of these are briefly summarized here.

With the advent of parallel processing computers, I developed parallel processing algorithms for matrix inversion and predictor-corrector integration of differential equations.

I worked with others to develop active structures using piezoelectric actuators.

I co-authored a landmark paper on design and applicability of telescopes for IR and sub-mm astronomy.

I co-authored a paper on use of C-60 as a propellant in ion propulsion.

I was Proposal Manager on several proposals to NASA for large-scale space missions. These included Suess-Urey (which won) to measure composition of the solar wind, OMEGA for gravitational wave detection (which lost), Kitty Hawk to fly gliders on Mars (which lost), and Deep Impact to explore the interior of a comet (which won). The total investment in Suess-Urey and Deep Impact was about 500,000,000 dollars.

I led an experimental study of an absorption compressor to compress Mars gas to usable pressures.

Post-2002:

I analyzed beaming solar power down from space to earth.

I published two papers on life support systems and radiation effects for human missions to Mars.

I acted as Proposal Manager for a proposal to NASA on “Mars Ground Penetrating Radar Proposal to Mars Science Laboratory” but it was not funded.

Acting as a consultant to JPL, I published a number of reports on topics such as: power system in space, a study of available water on Mars, a model of transfer trajectories from earth to Mars, solar energy on Moon and Mars, transporting hydrogen to Mars.

I wrote several papers published in the Mars Journal, dealing with life support and radiation effects.

Because of my reputation as a Proposal Manager, Stanford University asked me lead preparation of a proposal: “Interfacial Chemistry and Energy at SLAC and Stanford University (ICESS) Center".

Post-2008:

My work during this period was mainly divided between analysis of human missions to Mars, climate change, ice ages, and use of extraterrestrial materials in space missions.

My book on human missions to Mars was republished as a second edition in 2016 (582 pages) and a third edition in 2023 (614 pages).

My book on climate change was republished as a third edition in 2014 (816 pages).

My book on ice ages was republished as a third edition in 2019.

My book on extraterrestrial materials was republished as a second edition in 2018.

I also got interested in financial bubbles, and wrote a book on the subject. I also wrote chapters in encyclopedic compendiums.

Working as a consultant for MIT, I was a co-investigator on the Mars MOXIE Project from 2015 through 2023, to convert Martian CO2 into O2. I provided continuing documentation of work on the Project, I provided an end-to-end computer model of the end-to-end system, I cataloged the test data and analyzed it, and I provided an analysis of prospects for scaling up to full -scale proportions. This was a major accomplishment and MOXIE was recently recognized by Time Magazine.

Working with Ralph Ellis and Clive Best, we developed a model for ice ages over the past 2.7 million years and showed how the pacing of ice ages changed across the Mid-Pleistocene transition.

Books published:

Quantum Mechanics

by Donald Rapp 1971

Hardcover, 672 pages, Holt, Rinehart and Winston, ISBN 0030812941 (0-03-081294-1)

out of print; Reissued as paperback in 2013 at amazon.com

Statistical Mechanics

by Donald Rapp 1972

Hardcover, 330 pages, Holt, Rinehart and Winston, ISBN 0030856531 (0-03-085653-1) out of print; Reissued as paperback in 2012 at amazon.com

Statistical Mechanics - Reissue 2012 at amazon.com

Publication Date: March 22, 2012

. This text begins with a consideration of simple Boltzmann statistics, with particular application to the model of systems with two quantum states, and the Einstein and Debye treatments of the specific heats of a metal. After discussion of the Darwin-Fowler calculation of average distributions, the discussion moves on to the Bose-Einstein and Fermi-Dirac statistics of non-localized particles, and then to the classical limit approached by quantized systems in situations such as gas behavior and distributions of electric dipoles. This initial development occupies about the first third of the book. The text next takes up partition and thermodynamic functions of an ideal gas, with discussions of electronic, vibrational, and rotational (including internal rotation) contributions in atomic, diatomic, and polyatomic gases. A separate chapter is devoted to symmetry effects on wave functions and states, and the use of symmetry numbers in evaluating partition functions. This is a topic often glossed over, and frequently mystifying, to students. Chemical equilibrium is next considered, followed by chapters on the perfect quantum gas and imperfect gases where various intermolecular potentials are compared. The treatment of polyatomic molecules in terms of rigid rotations and small bond vibrations is developed, followed by a consideration of the transition state theory of chemical kinetics. The final chapter considers models of the liquid state and liquid-vapor equilibria. Despite its conciseness, this text covers a great deal of interesting ground.

Solar Energy

by Donald Rapp 1981

Hardcover, 516 pages, Prentice-Hall, ISBN 0138222134 (0-13-822213-4)

out of print

Human Missions to Mars: Enabling Technologies for Exploring the Red Planet

by Donald Rapp, hardback, 3rd edition

# Series: Springer Praxis Books

# Hardcover: 582 pages

# Publisher: Springer; 3rd ed. 2023 edition

# Language: English

# ISBN-10: 3319222481

# ISBN-13: 978-3319222486

# Product Dimensions: 6.1 x 1.3 x 9.2 inches

A human mission to Mars would be the pinnacle of Solar System exploration, representing not only an inspiring engineering achievement, but also the creation of a new era of expansion of humanity into space. Although NASA and others have developed scenarios for how such a mission might be carried out, many of the assumptions were optimistic and many details were left out. Because once embarked to Mars, there is no return to Earth for about 2.7 years, every system must be exquisitely reliable.

This book takes a critical view of the requirements for human missions to Mars from an engineering perspective. It discusses in detail all the technologies that need to be developed and demonstrated and examines the full range of elements critical to such missions, including recycling of life support consumables, radiation effects and shielding, aero-assisted orbit insertion and entry descent and landing amongst much else. The initial mass in low Earth orbit is used as a guide for Mission feasibility.

Lavishly illustrated, Human Missions to Mars is a highly readable yet realistic view of the possible future of the exploration of the Red Planet. For the first time it brings together a wide range of material currently fragmented in the literature and presents a cogent argument against the overly optimistic forecasts promulgated by NASA, the Mars Society and others. At the same time, it presents a plan to establish the technical basis for a credible human mission to Mars.

Assessing Climate Change – Temperatures, Solar Radiation and Heat Balance

Series: Springer Praxis Books – Environmental Sciences

by Donald Rapp, hardback, 3rd edition

# Series: Springer Praxis Books

# Hardcover: 816 pages

# Publisher: Springer; 3rd ed. 2014 edition (July 16, 2014)

# Language: English

# ISBN-10: 3319004549

# ISBN-13: 978-3319004549

# Product Dimensions: 6.7 x 2.1 x 9.6 inches

In ASSESSING CLIMATE CHANGE Donald Rapp has investigated a large body of scientific data relevant to climate change, approaching each element with necessary (but neutral) scientific skepticism. The chapters of the book attempt to answer a number of essential questions in relation to global warming and climate change. He begins by showing how the earth’s climate has varied in the past, discussing ice ages, the Holocene period since the end of the last ice age, particularly during the past 1000 years. He investigates the reliability of "proxies" for historical temperatures and assesses the hockey stick version of global temperatures for the past millennium. To do this effectively he looks carefully at how well near surface temperatures of land and ocean on earth have been monitored during the past 100 years or more, and looks at the utility and significance of a single global average temperature.

Topics such as the variability of the Sun and the Earth’s heat balance are discussed in considerable detail. The author also investigates how the current global warming trend compares with past fluctuations in earth’s climate and what is the likelihood that the warming trend we are experiencing now is primarily just another in a series of natural climate fluctuations as opposed to a direct result of human activities. A key factor in understanding what may happen in the future is to examine the credibility of the global climate models which claim that greenhouse gasses produce most of the temperature rise of the 20th Century, and forecast much greater impacts in the century ahead.

Finally, the book considers future global energy requirements, fossil fuel usage and carbon dioxide production, public policy relating to global warming, and agreements such as the Kyoto Protocol.

Bubbles, Booms and Busts - The Rise and Fall of Financial Markets

by Donald Rapp, second edition

# Paperback: 351 pages

# Publisher: Copernicus; 2nd ed. 2015 edition (November 15, 2014)

# Language: English

# ISBN-10: 1493910914

# ISBN-13: 978-1493910915

# Product Dimensions: 6.1 x 0.9 x 9.2 inches

This book builds upon previous discussions of booms and busts, particularly those of John Kenneth Galbraith. The first part of the book describes that stages of buildup and collapse of financial manias in terms of human element. These are divided into speculations, bootstraps and swindles. Discussions are provided on the distribution of wealth in the US, the nature of inflation, the role of the Federal Reserve in promoting bubbles, tax history and policies, debt (federal, state, municipal and personal), banks and banking, pension plans, and valuation of common stock.

The book then goes on to describe specific boom/bubble/bust cycles with many examples including the Florida land boom of the 1920s, the bull market of the late 1920s, the depression of the 1930s, the savings and loan scandals of the 1980s, the great bull stock market of 1982 to 1995, the crash of 1987, the dot.com mania, the sub-prime fiasco of 2002-2007, and a number of other bubbles and swindles.

Ice Ages and Interglacials

by Donald Rapp, second edition (3rd edition 2019)

# Series: Springer Praxis Books

# Paperback: 406 pages

# Publisher: Springer; 3rd ed. 2019 edition

# Language: English

# ISBN-10: 3642437656

# ISBN-13: 978-3642437656

# Product Dimensions: 6.6 x 1 x 9.4 inches

This book studies the history and gives an analysis of extreme climate change on Earth. In order to provide a long-term perspective, the first chapter briefly reviews some of the wild gyrations that occurred in the Earth’s climate hundreds of millions of years ago: snowball Earth and hothouse Earth. Coming closer to modern times, the effects of continental drift, particularly the closing of the Isthmus of Panama are believed to have contributed to the advent of ice ages in the past three million years. This first chapter sets the stage for a discussion of ice ages in the geological recent past (i.e. within the last three million years, with an emphasis on the last few hundred thousand years).

The second chapter discusses geological evidence for ice ages – how geologists surmised their existence prior to actual subsurface data that proved the theory. The following two chapters look at ice cores (primarily from Greenland and Antarctica). Chapter 3 discusses how ice core data is processed and Chapter 4 summarizes data obtained from ice cores. Chapter 5 discusses the processing of data obtained from ocean sediments, and summarizes the results, while the following chapter discusses data from other sources, such as "Devil’s Cave."

Chapter 7 summarizes the experimental results from Chapters 4, 5, and 6. It provides the foundation for comparison with theories in later chapters. In a perfect world, this data would be totally separate and disconnected from theory. Unfortunately, as the author shows, dating of much of the data was accomplished by "tuning" to the astronomical theory, which introduces circular reasoning.

Chapter 8 provides a brief overview of the various theories that have been devised to "explain" the patterns of alternating ice ages and interglacials that have occurred over the past three million years. This serves as an introduction to the following three chapters which presents the astronomical theory in its various manifestations, compare the astronomical theory with data, and then compare other theories with data. Finally, Chapter 12 summarizes what we think we know about ice ages and, more importantly, what we don’t know.

The second edition of this book has been completely updated. It studies the history and gives an analysis of extreme climate change on Earth. In order to provide a long-term perspective, the first chapter briefly reviews some of the wild gyrations that occurred in the Earth's climate hundreds of millions of years ago: snowball Earth and hothouse Earth. Coming closer to modern times, the effects of continental drift, particularly the closing of the Isthmus of Panama are believed to have contributed to the advent of ice ages in the past three million years. This first chapter sets the stage for a discussion of ices ages in the geological recent past (i.e. within the last three million years, with an emphasis on the last few hundred thousand years).

The Climate Debate

Most published books are one-sided in the climate debate between alarmists and skeptics. My book on the climate debate presents both sides of the debate with considerable technical detail and weighs the supporting evidence. It is found that in general, the data in climatology are very sparse and noisy. Yet climatologists seem willing to draw a dollar’s worth of conclusions from a penny’s worth of data. The sad truth is that we don’t really have good answers to the questions raised in the climate debate. My book shows why this is so. This new edition includes hundreds of references not included in the original version, and the book is expanded by more than 100 pages.

Use of Extraterrestrial Resources for Human Space Missions to Moon or Mars

(Springer Praxis Books / Astronautical Engineering) [Hardcover] second edition, 2018

This book carries out approximate estimates of the costs of implementing ISRU on the Moon and Mars. It is found that no ISRU process on the Moon has much merit. ISRU on Mars can save a great deal of mass, but there is a significant cost in prospecting for resources and validating ISRU concepts. Mars ISRU might have merit, but not enough data are available to be certain. In addition, this book provides a detailed review of various ISRU technologies. This includes three approaches for Mars ISRU based on processing only the atmosphere: solid oxide electrolysis, reverse water gas shift reaction (RWGS), and absorbing water vapor directly from the atmosphere. It is not clear that any of these technologies are viable although the RWGS seems to have the best chance. An approach for combining hydrogen with the atmospheric resource is chemically very viable, but hydrogen is needed on Mars. This can be approached by bringing hydrogen from Earth or obtaining water from near-surface water deposits in the soil. Bringing hydrogen from Earth is problematic, so mining the regolith to obtain water seems to be the only way to go. This will require a sizable campaign to locate and validate useable water resources. Technologies for lunar ISRU are also reviewed, even though none of them provide significant benefits to near-term lunar missions. These include oxygen from lunar regolith, solar wind volatiles from regolith, and extraction of polar ice from permanently shaded craters. The second edition provides new information on propellant requirements for scent from Mars, which is a critical factor in Mars ISRU. It also provides new information on crew size for human missions to Mars, which also affects ISRU requirements.

"In Situ Resource Utilization on Mars and Moon," chapter in book: Prospective Energy and Material Resources

Editor: Viorel Badescu, Springer-verlag, 2009.                             

"Ice Ages and Interglacials" chapter in Enyclopedia of Snow, Ice and Glaciers

Springer Verlag 2011

A published paper is described as "influential" if it is cited more than twenty times.  Below I emphasize the papers with at least 20 citations.  Many more have at least ten citations. One paper had 2,361 citations.

List of Publications

1. "Molecular Partition Functions in Terms of Local Bond Properties," with H. S. Johnston and D. R. Herschbach*, J. Chem. Phys., 31, 1652, 1959. *Nobel prize winner  (124 citations)

2. "A Complete Classical Theory of Vibrational Energy Exchange," J. Chem. Phys., 32, 735, 1960. (170 citations)

3. "The Nitric Oxide-Fluorine Dilute Diffusion Flame," with H. S. Johnston, J. Chem. Phys., 33, 695, 1960.   (46 citations)

4. "Large Tunneling Corrections in Chemical Reaction Rates," with H. S. Johnston, J. Amer. Chem. Soc., 83, 1, 1961.(218 citations)

5. "Comment on the Calculation of Rate Constants from Transition State Theory," with R. E. Weston, Jr., J. Chem. Phys., 35, 2907, 1962. (21 citations)

6. "Vibrational Energy Exchange in Molecular Collisions Involving Large Transition Probabilities," with T. E. Sharp, J. Chem. Phys., 38, 2641, 1963. (206 citations)

7. "Vibrational-Vibrational Energy Transfer in Resonant and Near Resonant Molecular Collision," with P. E. Golden, J. Chem. Phys., 40, 537, 1964.

8. "Vibrational Energy Exchange in Quantum and Classical Mechanics," J. Chem. Phys., 40, 2813, 1964.  (49 citations)

9. "Interchange of Vibrational Energy between Molecules in Collisions," J Chem. Phys. 43, 316 (1965). (97 citations)

10. "Effects of Approximations on Calculated Excitation Probabilities in Molecular Collisions," with T. E. Sharp, J. Chem. Phys., 43, 1233, 1965.

11. "Vibrational-Vibrational Translational Energy Transfer Between Two Diatomic Molecules," with A. Zelechow and T. Sharp, J. Chem. Phys., 49, 286, 1968. (107 citations)

12. "Resonant and Near-Resonant Vibrational-Vibrational Energy Transfer between Molecules in Collisions" Journal of Chemical Physics 40, 573. (189 citations)

13. "A Review of the Theory of Energy Transfer," with T. Kassal, Chem. Reviews, 69, 61, 1969.  (665 citations)

14. "Collinear Collisions of an Atom and Harmonic Oscillator," with F. E. Heidrick and K. R. Wilson, J. Chem. Phys., 54, 3885, 1971. (156 citations)

15. "Effects of an Attractive Potential on the Classical Theory of Vibrational Energy Exchange," with R. E. Turner, J. Chem. Phys., 35, 1076, 1961. (24 citations)

16. "Exact Quantum Mechanical Calculation of Energy Transfer," with T. Kassal, J. Chem. Phys., 48, 5287, 1968.

17. "Interchange of Charge Between Gaseous Molecules," with I. B. Ortenburger, J. Chem. Phys., 33, 1230, 1960. (49 citations)

18. "Evaluation of approximations used in the calculation of exciation by collision. I. Vibrational excitation by collision with T. Sharp Journal of Chemical Physis 43, 1233. (92 citations)

19. "Ion-Molecule Reactions in the Helium-Hydrogen Systems," with three co-workers, J. Chem. Phys., 34, 343, 1961.

20. "Charge Transfer Between Gaseous Ions and Atoms," with W. E. Francis, J. Chem. Phys., 37, 2631, 1962.  (1002 Citations)

21. "Accidentally Resonant Charge Transfer in the Protonosphere," J. Geophys. Res., 68, 1773, 1963. (31 citations)

22. "On the Relation Between Symmetric and Asymmetric Charge Exchange," J. Chem. Phys., 53, 1333, 1970.

23. "Simple Approximate Wave Functions for Alkali Atoms," with Jean Ward, J. Chem. Phys., 54, 2766, 1971.

24. "Wave Functions and Pseudopotential for Alkali Charge Transfer," with C. Chang, J. Chem. Phys., 57, 2766, 1971.

25. "Convergence of the Hydrogenic Expansion in H+, H. Scattering," with D. Dinwiddie, J. Chem. Phys., 57, 4278, 1972.  (90 citations)

26. "One Electron Model for Charge Exchange in Ion-Atom Collisions," with D. Storm, J. Chem. Phys., 57, 4278, 1972.

27. "Wave Functions and Pseudopotential for Sodium," with C. Chang, J. Chem. Phys., 58, 2657, 1973.  (25 citations)

28. "Excitation and Electron Capture in Collisions of He++ with H, " J. Chem. Phys., 58, 2043, 1973.

29. "Excitation and Electron Capture in Li+ - Li Collisions, " J. Chem. Phys., 59, 1266, 1973.  

30. "Approximate Solution of the Schroedinger Equation by Minimizing the Deviation," with C. Chang, J. Chem. Phys., 59, 972, 1973.

31. "Electron Capture and Excitation in Alkali Ion-Atom Collisions Using an Atomic Eigenfunction Expansion," with C. Chang, J. Chem. Phys., 59, 1276, 1973.  (23 citations)

32. "Electron capture and excitation in collisions of He++ with H. II. Covergence of the atomic expansion" Journal of Chemical Physics 61, 3777. (56 citations)

33. "The Impact Parameter Method for Proton-Hydrogen Atom Collisions. III. Use of Non-Hydrogenic Expansion Functions," with D. Storm, Phys. Rev., A8, 1784, 1973.

34. "Electron Transfer and Excitation in Collisions of He++ with H, J. Chem. Phys., 61, 3777, 1974. (38 citations)

35. "Variational Bounds on the 1s Charge Exchange Amplitude in Proton-Hydrogen Atom Scattering," with D. Storm, Phys. Re. Letters, 33, 137, 1974.

36. "Coupled State Calculations in H+, H Scattering," with D. Dinwiddie, D. Storm and T. E. Sharp, Phys. Rev., A5, 1290, 1972. 

37. "Ionization of the Hydrogen Molecule Near Threshold," with D. D. Briglia, Phys. Rev. Letters, 14, 245, 1965; and J. Chem. Phys., 42, 3201, 1965. (36 citations)

38. "Large Isotope Effect in Negative Ion Formation in H2, HD, and D2" with T. E. Sharp and D. D. Briglia, Phys. Rev. Letters, 14, 543,1965. (140 citations)

39. "Cross Sections for Dissociative Ionization of Gases by Electron Impact," with D. D. Briglia and P. E.  Golden, J. Chem. Phys., 42, 4081, 1965. (428 citations)

40. "Concerning the Possibility of Competition in Ionization of Molecules by Electron Impact," J. Chem. Phys., 55, 4154, 1971.

41. "Total Cross Sections for Ionization of Gases by Electron Impact," with P. E. Golden, J. Chem. Phys., 43, 1464, 1965. (2462 citations)

42. "Total Cross Sections for Negative Ion Formation in Gases by Electron Impact," with D. D. Briglia, J. Chem. Phys., 43, 1480, 1965  (651 citations)

43. "An Electron Cross Section Plotter," with D. D. Briglia, Revs. Sci. Insts., 36, 1259, 1965.

44. "On the Dipole Polarizabilities of Alkali Atoms," Indian Journal of Physics, 48, 901, 1974.

45. "Estimation of the Degree of Advancement of Petroleum Exploration in the United States," Energy Sources, 2, 125, 1975.

46. "A Critique of the Nationwide 55 M.P.H. Speed Limit," Energy Sources, 23, 377, 1976.3.

47. "The U.S. Energy Situation and Methanol as Fuel," 101 pages, "Proceedings of the 2nd Texas Symposium on Energy," June, 1982.

48. "ATU/Fort Hood Solar Total Energy Program - Final Report for April 1975 - September 1976," prepared by D. Rapp and co-workers for ERDA under Contract E-(40-1)-4924.

49. "I. Analysis of Insolation Patterns at Fort Worth, Texas," Energy Conversion, 16, 1, 1976.

50. "II. Prediction of Insolation at Fort Hood, Texas," Energy Conversion, 17, 31, 1977.

51. "III. The Relation Between Normal Incidence Solar Intensity, Total Insolation, and Weather at Fort Hood, Texas," Energy Conversion, 17, 163, 1977.

52. "IV. Construction of a Model Year Solar Intensity and Climate," Energy Conversion, 17, 173, 1977.

53. "V. Estimation of Availability of Solar Energy," Energy Conversion, 18, 31, 1978.

54. "On the Relation Between Global Insolation on Horizontal and Tilted Surfaces," with D. Oxley, Energy Conversion, 18, 39, 1978.

55. "Critique on the Solar Data Rehabilitation Procedures Used in Solmet II," Energy Conversion, 19, 101, 1979.

56. "Theoretical and Experimental Studies of Stratified Thermocline Storage of Hot Water," with M. Abdoly, Energy Conversion and Management, 22, 275, 1982. (109 citations)

57. "A Parallel Householder Tridiagonalization Stratagem Using Scattered Square Decomposition," with Y. Chang, S. Utku and M. Salama, Journal of Parallel Computing, 6, 297-312, 1988.

58. "A Parallel Householder Tridiagonalization Stratagem Using Scattered Row Decomposition," with Y. Chang, S. Utku and M. Salama, published in International Journal for Numerical Methods in Engineering, 26, 857-874, 1988.

59. "Active Structures for use in Precision Control of Large Optical Systems", with J. L. Fanson and E. H. Anderson, Optical Engineering, 29(11), 1320-1327 (1990). (33 citations)

60. Space Interferometry and Large Optics Program Prospectus, JPL Report D-6854, September, 1989.

61. "Direct Detection of Extra-Solar Planets", JPL Report D-6835, October, 1989.

62. "Direct and Indirect Detection of Extrasolar Planets and Brown Dwarfs", JPL Report, April, 1990.

63. "Binary Stars", JPL Report D-8028, January, 1991.

64. "Effect of Telescope Temperature and Surface Figure Accuracy on Performance of Conceptual IR and sub-mm Telescopes", JPL Report D-8175, January, 1991.

65. "Infrared Astronomy in the Post-SIRTF Era", JPL Report D-8482, May, 1991.

66. "Ecological Niches in IR and Sub-MM Astronomy: Sensitivity Comparisons for Proposed Future Observatories", with H. A. Thronson, B. Bailey and T. Hawarden, Publications of the Astronomical Soc. of the Pacific 107, 1099-1118, 1995.

67. "The Edison Radiatively Cooled IR Space Observatory", with many co-authors, Proc. SPIE, Vol. 1945, 13-14 April, 1993; also: "The Edison IR Observatory and the Study of Extra-Solar Planetary Material", with H. A. Thronson, T. G. Hawarden and J. Bally, Astrophysics and Space Science 212: 423-431 (1994).

68. "Sensor Cooling Handbook", JPL Report D-6483, June, 1989.

69. "The Dimensional Stability of Materials", JPL Report D-7667, July, 1990.

70. "Laminate Theory for Orthotropic Materials", JPL Report D-7747, August, 1990.

71. "Laminates Used in the Hubble Space Telescope", JPL Report D-7781, September, 1990.

72. "Precision Composite Mirror Panel Development Task - Final report of Four Year Program", JPL Report D-9204, December 20, 1991.

73. Donald Rapp, Charles E. Kohlhase, Jr., Brian K. Muirhead, Kenneth L. Atkins, Philip W. Garrison, William G.  Breckenridge, Richard H. Stanton, and Lincoln J. Wood, "Astronautics," in Encyclopedia of Applied Physics, Vol. 2, (George L. Trigg, ed.), pp. 25-63, American Institute of Physics, VCH Publishers, New York, 1991.

74. "Potential for Active Structures Technology to Enable Lightweight Passively Cooled IR Telescopes", JPL Report D-9449, March, 1992.

75. "Electrostatic Propulsion Using C60 Molecules", with S. Leifer and W. Saunders, Journal of Power and Propulsion 8, 1297-1300 (1992).

76. Effect of use of C-60 as a Propellant in Ion Thrusters, with S. Leifer, JPL Report D - 10169, October, 1992.

77. "Thermal Control", JPL Report D - 9959, July 29, 1992.

78. "Dimensional Stability of Materials", NASA Tech Brief NPO-18984, Sept. 9, 1993.

79. "The Suess-Urey Mission (Return of Solar Matter to Earth)," with several co-authors, IAA  IAA-L0705, 2nd IAA Intl. Conf. on Low Cost Planetary Missions, Johns Hopkins Univ., Maryland, April, 1996.

80. "Prospects and Limitations of Technical Approaches for Ultra Lightweight Space Telescopes," JPL Report D-13975, Sept. 30, 1996.

81. Genesis Space Mission Proposal to NASA Discovery Program, 1997 (funded at $220M).

82. "OMEGA" MIDEX Proposal, August, 1998.

83. Deep Impact Space Mission proposal to NASA Discovery Program, 1999 (funded at $340M).

84. KittyHawk Space Mission proposal to NASA Discovery Program, 2001.

85. "Adsorption Pump for Acquisition and Compression of Atmospheric CO2 on Mars," with 3 other authors, AIAA 97-2763, 1997.

86. "A Review of Mars ISPP Technology," JPL Report D-15223, 1997-8.

87. "NASA Technology Blueprint," JPL Publication 03-003, February, 2003.

88. "Solar Power on Mars," with other authors, 10-31-2001.

89. "Advanced Radioisotope Power Systems Report," with other authors, March, 2001.

90. "Solar Cell and Array Technology for Future Missions," with other authors, December, 2003.

91. "Mars Ground Penetrating Radar Proposal to Mars Science Laboratory", July, 2004.

92. "Assessment of Energy Storage Technology to Enable Future Space Science Missions," with other authors, August, 2004.

93. "Preliminary System Analysis of Mars ISRU Alternatives," with other authors, JPL Report D-31341, November, 2004.

94. "Solar Energy on Mars, Volume 1. Basics," JPL Report D-31341-1, November, 2004.

95. "Solar Energy on Mars, Volume 2, Calculations of Solar Energy on Mars," JPL Report D-31342-2, November, 2004.

96. "Accessible Water on Mars," JPL Report D-31343, December, 2004; Revision 5, June 2005, presented at ISDC National meeting.

97. "Sublimation Extraction of Mars H2O for Future In-Situ Resource Utilization," Greg S. Mungas, Donald Rapp, Robert W. Easter, Kenneth R. Johnson, and Thomas Wilson, ASCE Conference on Earth and Space 2006: Engineering, Construction, and Operations in Challenging Environment, 2005.

98. "Design Reference Missions for Human Exploration of Mars," with J. Andringa, JPL Report D-31340, January, 2005.

99. "Getting To And From The Moon, Mars And Other Bodies," JPL Report, August, 2005.

100. "Solar Energy on the Moon," informal JPL report, 2005.

101. "Transporting Hydrogen to Mars," informal JPL report, 2005.

102. "Fueling Around in Space," informal JPL report, 2006.

103. Rocket Science in a Nutshell," (with M. Adler) informal JPL report, 2006.

104. "Initial Mass in low Earth orbit," informal JPL report, 2006.

105. "Lunar In Situ Resource Utilization," informal JPL report, 2006.

106. "Mars Life Support Systems," The Mars Journal, Mars 2, 72-82, 2006; doi:10.1555/mars.2006.0005 

107. "Radiation Effects and Shielding Requirements in Human Missions to the Moon and Mars," The Mars Journal, Mars 2, 46-71, 2006; doi:10.1555/mars.2006.0004 

108. "An Analytical Tool for Tracking and Visualizing the Transfer of Mass at each Stage of Complex Missions," Donald Rapp, David Y. Oh, Robert Easter, Casey Heeg, Erick Sturm, Thomas Wilson, and Ryan Woolley, Space 2006, 19 - 21 September 2006, San Jose, California, AIAA 2006-7254.

109. Solar Power Beamed from Space," Astropolitics 5, 63-86 (2007).

110. "Interfacial Chemistry and Energy at SLAC and Stanford University (ICESS) Center," Stanford University document, 2008.

111. "Advanced Energy Solutions," internal JPL document, with S. Surampudi, 2008.

112. "Oxyatmoversion of the terrestrial planets, Caltech-JPL document, 2008.

113. Adsorption pump for Acquisition and compression of CO2 on Mars" AIAA 97-2763.

114. Pre-landing plans for Mars Oxygen In-SituResource Utilization Experiment (MXIE) Science Operations, Acta Astronautica 192, 301-313 (2022)(13 citations)

115. Hecht, M., J. Hoffman, D. Rapp and others,  Mars Oxygen ISRU Experiment (MOXIE) Space Science Reviews 217:9 (2021) (123 citations)

116. Jeffrey A. Hoffman Michael H. Hecht Donald Rapp Joseph J. Hartvigsen David J. Eisenman + 19 authors, Mars Oxygen ISRU Experiment (MOXIE) Preparing for human Mars Exploration, SCIENCE ADVANCES 31 Aug 2022 Vol 8, Issue 35 (43 citations)

117. D. Rapp with others, "The Mars Oxygen ISRU Experiment" AIAA Space 2015 Conference and Exhibition (39 citations)

118. Donald Rapp, Jeffrey A. Hoffman, Forrest Meyen, Michael H. Hecht and The MOXIE Team, The Mars Oxygen ISRU Experiment (MOXIE) on the Mars 2020 Rover, AIAA 2015-4561

119. D. Rapp and E. Hinterman, Adapting a Mars ISRU System to the Changing Mars Environment, Space Science and Technology, 17 May 2023 Vol 3 Article ID: 0041

120. Vassilis J. Inglezakis, Donald Rapp, Panos Razis and Antonis A. Zorpas, "Chemical Engineering beyond Earth: Astrochemical Engineering in the Space Age," Sustainability 2023, 15, 13227.

121. D. Rapp and V. Inglevakis (2024) "Mars ISRU with focus on atmospheric processing for near term application" Applied Sciences 14. (8,607 views and 866 downloads)

122. D. Rapp (2024) "Near Term Mars and Lunar ISPP: complexity vs. Simplicity" Space: Science and Technology" Space Sci. Technol.2024;4:Article 0188. https://doi.org/10.34133/space.0188 (800 downloads)

123. D. Rapp (2024) "Estimate of temperature rise in the 21st century for various scenarios" IgMin Res.July 11, 2024; 2(7): 564-569. IgMin ID: igmin218; DOI:10.61927/igmin218  -  (9,600 views, 1,800 downloads)

124. D. Rapp (2024) Revisiting Ice Ages Cycles. IgMin Res 2024, 2 (8), 726-733. https://doi.org/10.61927/igmin239 (60,200 views, 1,000 downloads)

125. D. Rapp (2024) "Mars Ascent Propellants and Life Support Resources -"Take it or Make it?" IgMin Res. July 29, 2024; 2(7): 673-682. IgMin ID: igmin232; DOI:10.61927/igmin232; Available at: igmin.link/p232  -  (12,600 views and 1,240 downloads)

126. D. Rapp (2024) ISRU Commentary - "The value of utilization of extraterrestrial resources for propellant production for space exploration- a perspective" Acad. J. Engr. Studies 3 (4) DOI 10:31031/AES2024.03.000570 --- https://crimsonpublishers.com/aes/pdf/AES.000570.pdf

127. D. Rapp (2024) Lunar-Derived Propellants for Fueling Mars-Bound Spacecraft in Cis-Lunar Space. IgMin Res 2024, 2 (9), 744-751. https://doi.org/10.61927/igmin242  (9,000 views, 1,400 downloads)

128.  Rapp, D. (2024) "Will SpaceX Send Humans to Mars in 2028?". IgMin Res 2024, 2 (12), 969-983. https://doi.org/10.61927/igmin274. (32,000 views, 1,200 downloads)

129. Rapp, D. How Increased CO2 Warms the Earth-Two Contexts for the Greenhouse Gas Effect. IgMin Res 2024, 2 (10), 854-859. https://doi.org/10.61927/igmin259.(45,000 views, 1,200 downloads)

130. Rapp D. Use of Extraterrestrial Resources and Recycling Water: Curb Your Enthusiasm. IgMin Res. September 27, 2024; 2(9): 775-784. IgMin ID: igmin247; DOI: 10.61927/igmin247 (13,000 views, 830 downloads)

131. Rapp, D. Preparing for SpaceX mission to Mars 2025  https://doi.org/10.61927/igmin292 (55,500 views, 1,500 downloads)

132. Rapp, D. Dominance of Institutions vs. Individuals in Search Engine responses to Queries Journal of Education and Language Studies 2025. https://juniperpublishers.com/oajels/articleinpress-oajels.php

133. Rapp, D. Revisiting 2,000 Years of Climate Change: (Bad Science and the Hockey Stick) https://www.igminresearch.com/articles/pdf/igmin296.pdf 30,000 views, 1,180 downloads

134. Rapp D. Human Missions to Mars Using the Starship. IgMin Res. August 06, 2025; 3(8): 268-277. IgMin ID: igmin308; DOI: 10.61927/igmin308; Available at: igmin.link/p308 13,000 views, 700 downloads

135. Rapp, D. Space News Report September 12, 2025, https://spacenews.com/how-carrying-enough-water-to-make-return-trip-propellant-simplifies-a-starship-mission-to-mars/

136. Rapp, D. and V. Inglezakis Accessible H2O on Mars – A Critical Review of Current Knowledge. IgMin Res. November 25, 2025; 3(11): 407-439. IgMin ID: igmin322; DOI: 10.61927/igmin322; Available at: igmin.link/p322 4,500 views, 690 downloads

137. Rapp, D. How Increasing CO2 Warms the Earth Rapp D. How Increased CO2 Warms the Earth. IgMin Res. December 09, 2025; 3(12): 454-461. IgMin ID: igmin324; DOI: 10.61927/igmin324; Available at: igmin.link/p324 5,500 views, 550 downloads

138. Rapp D. Landing Site Selection for the First Human Mission to Mars. IgMin Res. February 09, 2026; 4(2): 066-075. IgMin ID: igmin333; DOI:10.61927/igmin333; Available at: igmin.link/p333 5,200 views, 420 downloads

139. Rapp D, Inglezakis V. Accessible H2O on Mars – A Critical Review of Current Knowledge. IgMin Res. November 25, 2025; 3(11): 407-439. IgMin ID: igmin322; DOI: 10.61927/igmin322; Available at:igmin.link/p322 6,700 views, 690 downloads