Donald Rapp was full professor of physics at the University of Texas 1969-1979, and Chief Technologist of the Mechanical and Chemical Engineering Division of JPL from 1979 to 2002.
He was manager of the Mars Exploration Technology Program at JPL for a period, and he was manager of the In Situ Propellant Production (ISPP) task in this Program. He wrote a landmark report on converting Mars resources into usable propellants for return to Earth. He wrote the Mars Technology Program Plan in 2001.
He was proposal manager at JPL for two missions that were implemented in space: Suess-Urey mission to collect solar wind, and Deep Impact to observe interior of a comet.
During the period 2001-2002, he played an important role in JPL efforts in developing concepts for utilization of extraterrestrial resources in Mars missions. In 2002 he wrote the NASA Office of Space Science Technology Blueprint for Harley Thronson, NASA Technology Director, a 100-page assessment of technology needs and capabilities for future missions.
In the period 2003-2006, he prepared a revised and expanded version of the Technology Blueprint for Harley Thronson at NASA HQ. In 2004, he was Proposal Manager for a proposal for a ground-penetrating radar experiment for the Mars Science Laboratory as well as a glider mission on Mars.
In the period 2004-2006, he concentrated on mission design for Mars and lunar human missions. This work led to his writing the book Human Missions to Mars that was published by Praxis/Springer in 2007. This was a major work, comprising 520 pages with over 200 figures. It included a chapter on in situ resource utilization (ISRU) on Mars.
He was the lead person at JPL for ISRU technology for several decades. In this role, he carried out research and analysis leading to a number or reports and publications through the 1980s, 1990s and into the 2000s.
Since 2014, he has been Co-Investigator on the Mars OXygen In Situ Experiment(MOXIE) that operated on Mars in 2021-022 to routinely produce oxygen from Martian carbon dioxide.
The original book Human Missions to Mars was updated to a second edition in 2015, and is now presented as a third edition in 2022 with many new references and updates.

Examines the costs of implementing in situ resource utilization on the Moon and Mars

Provides a complete review of the field of extraterrestrial resources with independent analyses that are not part of the NASA party line

Includes three approaches for Mars ISRU based on processing only the atmosphere: solid oxide electrolysis, reverse water gas shift reaction, and absorbing water

Part 1 - Mars ISRU: Human Missions to Mars.- Mars Resources.- Acquiring Compressed CO2.- Processes Utilizing Mainly CO2 from the Atmosphere.- The Sabatier/Electrolysis Process.- Obtaining H2O on Mars.- Obtaining Water from the Atmosphere.- Ancillary Needs for Mars ISRU.- Part 2: Lunar ISRU.- Lunar Resources.- Lunar ISRU Processes.- NASA Accomplishments and Plans.- Part 3. Value of ISRU: Value of Mars ISRU.- Value of Lunar ISRU.- Future Factors that could influence Mars ISRU.- Part 4. Refueling Spacecraft in LEO Using Propellants Derived from the Moon or Asteroids.- Introduction.- Value of Lunar Water in LEO.- Percentage of Water Mined on the Moon Transferred to LEO.- Refueling Spacecraft with Propellants Derived from Asteroids.- Part 5. Recent NASA Plans: Some History.- Recent NASA Planning.