Electric propulsion thrusters are replacing small chemical thrusters used for spacecraft control and orbital maneuvers. These thrusters use a variety of mechanisms to convert electrical power into thrust and in general provide superior specific impulse in comparison to chemical systems. Electric propulsion has been under development for the last fifty years, and almost all thrusters are designe...

The safe, affordable and effective transfer of ever-larger payloads and eventually personnel beyond Low Earth Orbit (LEO) is a major challenge facing future commercial development and human exploration of space. Without reusable systems, sustained exploration or largescale development beyond LEO appears to be economically non-viable. However, reusable systems must be capable of both good fuel e...

(les Enjeux de la propulsion et de l'energetique a l'aube du 2P me siecle) (les Enjeux de la propulsion et de l'energetique a l'aube du 2P me siecle)

Performance expectations of closed-Brayton-cycle heat exchangers to be used in 100-kWe nuclear space power systems were forecast. Proposed cycle state points for a system supporting a mission to three of Jupiter’s moons required effectiveness values for the heat-source exchanger, recuperator and rejection exchanger (gas cooler) of 0.98, 0.95, and 0.97, respectively. Performance parameters such ...

the repetitious nature of propelling a wheelchair has been associated with the high incidence of injury among manual wheelchair users (mwus), mainly in the shoulder, elbow and wrist. recent literature has found a link between handrim biomechanics and risk of injury to the upper extremity. the valid measurement of three‑dimensional net joint forces and torques, however, can lead to a better unde...

Background/Objective: The high demand on the upper limbs during manual wheelchair (WC) use contributes to a high prevalence of shoulder pathology in people with spinal cord injury (SCI). Leveractivated (LEVER) WCs have been presented as a less demanding alternative mode of manual WC propulsion. The objective of this study was to evaluate the shoulder muscle electromyographic activity and propul...

Under Project Prometheus, the National Aeronautics and Space Administration (NASA) investigated deep space missions that would utilize space nuclear power systems (SNPSs) to provide energy for propulsion and spacecraft power. The initial study involved the Jupiter Icy Moons Orbiter (JIMO), which was proposed to conduct in-depth studies of three Jovian moons. Current radioisotope thermoelectric ...

This paper is a discussion of how the many long-lead development elements required for the realization of a future nuclear thermal propulsion (NTP) system can be effectively leveraged from the ongoing work being conducted on the J-2X engine program for the Constellation Program. Development studies conducted to date for NTP forward planning have identified a number of technical areas that will ...

John R. Brophy , Jet Propulsion Laboratory, Caltech Louis Friedman ,Executive Director Emeritus, The Planetary Society Nathan J. Strange, Jet Propulsion Laboratory, Caltech Thomas A. Prince . Director, Keck Institute for Space Studies, Caltech Damon Landau, Jet Propulsion Laboratory, Caltech Thomas Jones . Florida Institute for Human and Machine Cognition Russell Schweickart , B612 Foundation C...

The naval industry has integrated the generation of energy through nuclear processes, due to large amount that is produced in these for example, ship NS OTTO HAHN, which used a propulsion plant with generated by reactor pressurized water (PWR), operated under fission process. Also, other examples are military ships and icebreakers. In order know contribution this type plants, work carries out m...