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

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

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.

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  

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

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

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

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

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

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.  

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

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.

12. "A Review of the Theory of Energy Transfer," with T. Kassal, Chem. Reviews, 69, 61, 1969.  

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

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

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

16. "Interchange of Charge Between Gaseous Molecules," with I. B. Ortenburger, J. Chem. Phys., 33, 1230, 1960.

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

18. "Charge Transfer Between Gaseous Ions and Atoms," with W. E. Francis, J. Chem. Phys., 37, 2631, 1962.  

19. "Accidentally Resonant Charge Transfer in the Protonosphere," J. Geophys. Res., 68, 1773, 1963.

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

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

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

23. "Convergence of the Hydrogenic Expansion in H+, H. Scattering," with D. Dinwiddie, J. Chem. Phys., 57, 4278, 1972.  

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

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

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

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

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

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

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

31. "Electron Transfer and Excitation in Collisions of He++ with H, J. Chem. Phys., 61, 3777, 1974.

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

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

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

35. "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.

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

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

38. "Total Cross Sections for Ionization of Gases by Electron Impact," with P. E. Golden, J. Chem. Phys., 43, 1464, 1965.

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

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

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

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

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

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

45. "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.

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

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

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

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

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

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

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

53. "Theoretical and Experimental Studies of Stratified Thermocline Storage of Hot Water," with M. Abdoly, Energy Conversion and Management, 22, 275, 1982.

54. "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.

55. "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.

56. "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).

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

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

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

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

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

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

63. "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.

64. "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).

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

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

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

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

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

70. 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.

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

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

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

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

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

76. "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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

94. "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.

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

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

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

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

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

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

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

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

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

104. "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 

105. "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.

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

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

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

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

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

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

112. Mars Oxygen ISRU Experiment (MOXIE) Space Science Reviews 217:9 (2021)

113. 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

114. 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

115. 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

116. 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.

A published paper is described as "influential" if it is cited more than twenty times.  Below I list the papers with at least 80 citations. I have a number of other publications with 20 to 80 citations not listed here.