The NASA In-Space Propulsion Technology project's current products and future directions
Since its inception in 2001, the objective of the In-Space12 Propulsion Technology (ISPT) project has been developing and delivering in-space propulsion technologies that enable or enhance NASA robotic science missions. These in-space propulsion technologies are applicable, and potentially enabling for future NASA flagship and sample return missions currently under consideration, as well as having broad applicability to future Discovery and New Frontiers mission solicitations. This paper provides status of the technology development, applicability, and availability of in-space propulsion technologies that recently completed, or will be completing within the next year, their technology development and are ready for infusion into missions. The paper also describes the ISPT project's future focus on propulsion for sample return missions.
NEXT Ion Propulsion System Development Status and Performance
*† NASA’s Evolutionary Xenon Thruster (NEXT) project is developing next generation ion propulsion technologies to provide future NASA science missions with enhanced mission performance benefit at a low total development cost. The objective of the NEXT project is to advance next generation ion propulsion technology by producing engineering model and prototype model system components, validating these through qualification-level and integrated system testing, and ensuring preparedness for transitioning to flight system development. This paper describes the NEXT ion propulsion system development status, characteristics and performance. A review of mission analyses results conducted to date using the NEXT system is also provided.
Vibration Test of a Breadboard Gimbal for the NEXT Ion Engine
*† † ‡ § ** The NEXT propulsion system is an advanced ion propulsion system presently under development that is oriented towards robotic exploration of the solar system using solar electric power. The subsystem includes an ion engine, power processing unit, feed system components, and thruster gimbal. The breadboard gimbal that has been developed is a lightweight, two-axis design using a four-bar linkage mechanism that provides a positive captured configuration for launch while providing for up to twenty degrees of thrust angle articulation while in the operational configurat ion. In this paper, the results of dynamic environmental testing of the gimbal with a thruster mass model are presented. The gimbal/mass-model assembly was subjected to qualification-level random vibration loads and survived with no significant issues. Acceleration and force data were acquired at the interface between the gimbal and the thruster to facilitate structural modeling of the thruster in response to the loads transmitted through by the gimbal. Shock spectra at levels significantly less than the project requirements were applied to the gimbal/mass-model assembly using two different methods in order to characterize the transmission of shock loads from the base of the gimbal to the thruster location. Hammer blow impacts were more representative than vibration table shock approximations of actual pyrotechnic devices and the expected shock attenuation through the gimbal. Post-test analysis showed that the gimbal structure stresses are comfortably within design margins.