Claude R. Joyner

• Fellow at Aerojet Rocketdyne

Impulsively-efficient low-enriched uranium (LEU) nuclear thermal propulsion (NTP) and nuclear-electric propulsion (NEP) are two near-term technologies that can reduce the logistics, trip time, and risks associated with long-duration crewed missions to Mars starting in the 2030's. During preliminary mission planning, interplanetary trajectories are...

View Video Presentation: https://doi.org/10.2514/6.2022-4373.vid Aerojet Rocketdyne (AR) has long had a vision for providing propulsion that permits exploration and extensive travel capability across the Solar System. AR’s history and current efforts include providing propulsion and power for NASA’s far-reaching exploration goals and science missio...

View Video Presentation: https://doi.org/10.2514/6.2022-4270.vid The RL10 is the highest performance upper stage rocket engine in the world. It has provided precisely controlled, reliable power for a wide variety of earth orbital and interplanetary missions. Originally designed as a 15K lb thrust engine for the Atlas Centaur high energy upper stage...

View Video Presentation: https://doi.org/10.2514/6.2022-4217.vid With the resurgence of using Nuclear Electric Propulsion (NEP) for human Mars exploration missions, particularly opposition class missions, Aerojet Rocketdyne (AR) has begun to evaluate Mars Transfer Vehicles (MTVs) that use a hybrid NEP and chemical propulsion approach. These NEP/Che...

View Video Presentation: https://doi.org/10.2514/6.2021-3611.vid Since 2016, AR has been working with NASA and members of industry as part of the NASA Space Technology Mission Directorate. The initial goal of this project was to determine the feasibility and affordability of a low enriched uranium (LEU)-based nuclear thermal propulsion (NTP) engine...

View Video Presentation: https://doi.org/10.2514/6.2021-3610.vid The long term, sustained exploration of Mars will require the focused efforts of a collective of national space agencies, public and private industry, and academia. The goal of this exploration will not be to just plant a flag and leave a boot print, but to continue beyond the first m...

View Video Presentation: https://doi.org/10.2514/6.2021-3268.vid AR SpaceCrane Family of Lunar Lander Vehicles: A Common Architecture For Enhanced Mission Flexibility and Agility Peter D. Kinsman, Claude R. Joyner II, Timothy Kokan, Daniel J.H. Levack, Dennis E. Morris, Christopher Reynolds Aerojet Rocketdyne, Canoga Park, California 91309, USA, Ae...

Nuclear thermal propulsion (NTP) has been extensively researched as a potential main propulsion option for human Mars missions. NTP's combination of high thrust and high fuel efficiency makes it an ideal main propulsion candidate for these types of missions, providing architectural benefits including smaller transportation system masses, reduced tr...

A flight demonstrator (FD) High-assay Low Enriched Uranium (HALEU) Nuclear Thermal Propulsion (NTP) system that can advance the technology for a Mars crew transportation system extensively studied in late 2019 and early 2020. This demonstrator development activity would use a nuclear fuel material that is capable of high temperature (e.g., peak tem...

While the near-term focus of NASA’s human exploration program is on the return of humans to the Moon in the mid-2020s, the human exploration of Mars continues to be NASA’s horizon goal. A key element of human Mars exploration architectures is the in-space propulsion system required for transferring crew and cargo between Earth orbit and Mars orbit....

As part of a NASA funded effort, Aerojet Rocketdyne, along with other industry partners, has been examining the feasibility of a Low Enriched Uranium (LEU) Nuclear Thermal Propulsion (NTP) system and its application to various human-class Mars missions. Recent analysis for NTP vehicle design focused on Mars opposition class missions in the mid- to...

NASA, Aerojet Rocketdyne, and other members of industry have been performing engine and mission trade studies to examine low enriched uranium (LEU) approaches for nuclear thermal propulsion (NTP) powered vehicles. Based upon commercial terrestrial technology to reduce proliferation and security concerns, LEU provides a path to a more affordable “ne...

Since 2016, Aerojet Rocketdyne (AR) has been working with NASA and other industry partners to improve the design and increase the feasibility of Low Enriched Uranium (LEU) NTP engine systems that may provide programmatic and cost benefits over older Highly Enriched Uranium (HEU) designs. From the project’s inception, mission analysis has primarily...

Nuclear thermal propulsion (NTP) has been extensively researched as a potential main propulsion option for human Mars missions. NTP's combination of high thrust and high fuel efficiency makes it an ideal main propulsion candidate for these types of missions, providing architectural benefits including smaller transportation system masses, reduced tr...

The future of human exploration missions to Mars is dependent on solutions to the technology challenges being worked on by the National Aeronautics and Space Administration (NASA) and industry. One of the key architecture technologies involves propulsion that can transport the human crew from Earth orbit to other planets and back to Earth with the...

NASA and industry are studying future human exploration missions to Mars that occur across multiple mission opportunities between 2030 through 2050. Aerojet Rocketdyne is supplementing previous work with Conjunction Class round-trip Mars missions by studying Opposition Class missions. Opposition Class missions have the advantage of shorter total mi...

NASA and industry are studying future human exploration missions to Mars that occur across multiple mission opportunities between 2030 through 2050. Aerojet Rocketdyne is supplementing previous work with Conjunction Class round-trip Mars missions by studying Opposition Class missions. Opposition Class missions have the advantage of shorter total mi...

Aerojet Rocketdyne is working with NASA, the Department of Energy, and other industry to define a more affordable path to nuclear propulsion and power use for lunar, Mars and broader solar system exploration missions. Aerojet Rocketdyne's (AR) recent work builds on the legacy design, analysis, and testing knowledge gained from the Rover/NERVA (Nuc...

NASA and its international partners have identified an exciting plan for opening up cislunar space and making the first steps toward human exploration of Mars in the 2020s. 1 Aerojet Rocketdyne is working with NASA to develop higher power Electric Propulsion (EP) in support of this vision. The Advanced Electric Propulsion System (AEPS) is being dev...

Since 2016, Aerojet Rocketdyne (AR) has been working with NASA and other industry partners to improve the design and increase the feasibility of Low Enriched Uranium (LEU) NTP engine systems that have clear programmatic and cost benefits over older Highly Enriched Uranium (HEU) designs. Part of this study effort is examining potential value-added d...

Lunar Surface Logistical Capability: A Study of Spacecraft Needed to Support Human Habitation, Scientific Research, and Commercial Operations on the Lunar Surface Abstract In 2018, NASA revealed plans for human space exploration moving forward into the 2020’s. The focus of these evolving plans, for the next decade, will be the launch, assembly and...

Studies of Nuclear Thermal Propulsion (NTP) over the past several decades, and updated most recently with the examination of Low Enriched Uranium (LEU), have shown nuclear propulsion is an enabling technology to reach beyond this planet and establish permanent human outposts at Mars or rapidly travel to any other solar system body. The propulsion n...

If humans are to reach beyond this planet and establish permanent outposts at Mars or any other solar system body, advanced propulsion will be needed. Optimum advanced propulsion needs high thrust to operate within the deep gravity well of a planet and also needs to provide high propulsive efficiency for rapid travel and reduced total spacecraft ma...

Nuclear Thermal Propulsion (NTP) is a proven technology that provides the performance required to enable benefits in greater payload mass, shorter transit time, wider launch windows, and rapid mission aborts due to its high specific impulse (Isp) and high thrust. Aerojet Rocketdyne (AR) has stayed engaged for several decades in working NTP engine s...

In December 2017 the current administration made a single sentence change to US Space Policy Directive-1 which has refocused the country’s space explorations efforts on a “return of humans to the Moon for long-term exploration and utilization.” With this mandate the National Aeronautics and Space Administration has centered its near-term developmen...

NASA and industry are studying future human exploration missions to Mars that occur across multiple mission opportunities between 2030 to the late 2050's. Aerojet Rocketdyne (AR) has been analyzing ballistic transfers for Earth to Mars for roundtrip missions over an even grid of departure dates and transfer times during those opportunities. Aerojet...

The future of human exploration missions to Mars are dependent on solutions to the technology challenges being worked by NASA and industry. One of the key architecture technologies required to successfully send human to Mars involves selecting the propulsion system that can transport the crew from Earth orbit to Mars and back to Earth with the lowe...

Future human exploration missions to Mars are being studied by NASA and industry. Several approaches to the Mars mission are being examined that use various types of propulsion for the different phases of the mission. The choice and implementation of certain propulsion systems can significantly impact mission performance in terms of trip time, spac...

Future human exploration missions to Mars are being studied by NASA, industry and academia. Many approaches to the Mars mission are being examined that use various types of propulsion for the different phases of the mission. The choice and implementation of propulsion system options can be optimally determined based on specific mission criteria suc...

Future human exploration missions to Mars are being studied by NASA and industry. Several approaches to the Mars mission are being examined that use various types of propulsion for the different phases of the mission. The choice and implementation of propulsion system options can significantly impact mission performance in terms of trip time, space...

Future human exploration missions to Mars are being studied by NASA and industry. Several approaches to the Mars mission are being examined that use various launch vehicle configu-rations and different types of propulsion for the various phases of the mission.. Understand-ing the key impacts of key systems being considered for both cargo transfer a...

NASA is currently underway developing the Space Launch System (SLS) to carry crew and cargo beyond low Earth orbit (LEO). The heavy lift capabilities of the SLS will enable spacecraft and mission architecture flexibility not achievable with current or proposed alternative, medium and heavy lift launch vehicles. The SLS is being designed in an evolu...

The Nuclear Thermal Rocket (NTR) represents the next evolutionary step in cryogenic liquid rocket engines. Deriving its energy from fission of uranium-235 atoms contained within fuel elements that comprise the engine’s reactor core, the NTR can generate high thrust at a specific impulse of ~900 seconds or more – twice that of today’s best chemical...

This study examines the impact of the launch capabilities provided by the planned Space Launch System (SLS) Block 2 vehicle on the solar electric propulsion (SEP) power levels required for large cargo prepositioning missions to Mars orbit. Our analysis shows that the additional launch capability planned for the SLS vehicle enables a dramatic reduct...

A mission comparison of solar electric propulsion vehicles with Hall effect and gridded ion thrusters utilizing bismuth, xenon, and krypton propellant options is presented. Three example missions are examined: (1) geosynchronous transfer orbit to geostationary orbit, (2) high Earth orbit to the near Earth asteroid 2008 EA9, and (3) high Earth orbit...

Recent exploration architectures are considering capability based approaches that use various propulsion technologies that need flight qualification. When human exploration missions come to fruition, rapidity of mission flight time and minimization of the number of flight elements will be important to reduce risk and cost. Nuclear thermal propulsio...

Summary/Conclusions During architecture studies and conceptual design studies, details of any new items to be traded arerarely known: Part counts, features of individual parts, the manufacturing processes to be used, and eventhe weight are not easily obtainable. WBS details are not available without large expenditures of effort.What is available ar...

In defining a space vehicle architecture, the propulsion system and related subsystem choices will have a major influence on achieving the goals and objectives desired. There are many alternatives and the choices made must produce a system that meets the performance requirements, but at the same time also provide the greatest opportunity of reachin...

The purpose of this paper is to catalog and summarize the efforts over the past thirty years and more to define, analyze and design concepts by Pratt Whitney Rocketdyne that employed a fission-based reactor as a propulsion system for exploration of the Solar System. Pratt & Whitney and Rocketdyne legacy engineering efforts have resulted in a wide v...

The purpose of this paper is to discuss the results of mission-based system trades when using a nuclear thermal propulsion (NTP) system for Solar System exploration. The results are based on comparing reactor designs that use a ceramic-metallic (CERMET), graphite matrix, graphite composite matrix, or carbide matrix fuel element designs. The composi...

The Vision for Space Exporation, a space systems activity, focused on returning to the Moon and continuing turn to Flight and for completing the International space Station (ISS). NASA Administrator laid out the details that resulted from the agency's Exploration Systems Architecture Study on September, 2005. The launch vehicles that replace the sh...

In space, whether in a stable satellite orbit around a planetary body or traveling as a deep space exploration craft, power is just as important as the propulsion. The need for power is especially important for in-space vehicles that use Electric Propulsion. Using nuclear power with electric propulsion has the potential to provide increased payload...

The authors discuss the Taguchi method as an approach to design optimization for quality. The method is briefly explained, and its application is illustrated for a propulsion system design optimization study for an advanced space transportation vehicle. The results suggest that the Taguchi method is a systematic and efficient approach that can aid...

The approach used in a propulsion system design optimization study for an advanced space transportation vehicles is described. The Taguchi method, based on statistically designed experiments, is utilized to conduct a series of parametric trade studies to optimize the vehicle weight. The role of Taguchi methods on conceptual aerospace vehicle design...

The application of advanced technologies to future launch vehicle designs would allow the introduction of a rocket-powered, single-stage-to-orbit (SSTO) launch system early in the next century. For a selected SSTO concept, a dual mixture ratios, staged combustion cycle engine was selected as the baseline propulsion system. A series of parametric tr...

The application of advanced technologies to future launch vehicle designs would allow the introduction of a rocket-powered, single-stage-to-orbit (SSTO) launch system early in the next century. For a selected SSTO concept, a dual mixture ratio, staged combustion cycle engine that employs a number of innovative technologies was selected as the basel...

This paper will describe the application of Response Surface Methodology in creating generalized trajectory equations for use in a vehicle design/sizing process and the evaluation of combinations of independent propulsion design variables in order to obtain a launch vehicle design that has been optimized for minimum dry weight or system cost. The p...

In 2001-2002, the USAF developed an Operationally Responsive Spacelift Mission Needs Statement (ORS MNS) that defined the requirement for responsive, on-demand access to, through, and from space. This requirement not only encompassed the spacelift mission of delivering payloads rapidly to or from orbit, and their operation on orbit; it also states...

In defining a space vehicle architecture, the propulsion system and related subsystem choices will have a major influence on achieving the goals and objectives desired. There are many alternatives and the choices made must produce a system that meets the performance requirements, but at the same time also provide the greatest opportunity of reachin...