Abstract As a critical part of the NEXT test validation process, a multiple -string integration test was performed on the NEXT propellant management system and ion thrusters. The objectives of this test were to verify that the PMS is capable of providing s table flow control to multiple thrusters operating over the NEXT system throttling range and to demonstrate to potential users that the NEXT PMS is ready for transition to flight. A test plan was developed for the sub-system integration test for verification of PMS and thruster system performance and functionality requirements. Propellant management system calibrations were checked during the single and multi-thruster testing. The low pressure assembly total flow rates to the thruster(s) were within 1.4 percent of the calibrated support equipment flow rates. The inlet pressures to the main, cathode, and neutralizer ports of Thruster PM1R were measured as the PMS operated in 1-thruster, 2-thruster, and 3-thruster configurations. It was found that the inlet pressures to Thruster PM1R for 2-thruster and 3 -thruster operation as well as single thruster operatio n with the PMS c ompare very favorably indicating that flow rates to Thruster PM1R were similar in all cases. Characterizations of discharge losses, accelerator grid current, and neutralizer performance were performed as more operating thrusters were added to the PMS. There were no variations in these parameters as thrusters were throttled and single and multiple thruster operations were conducted. The propellant management system power consumption was at a fixed voltage to the DCIU and a fixed thermal throttle temperature of 75 °C. The total power consumed by the PMS was 10.0, 17.9, and 25.2 W, respectively, for single, 2-thruster, and 3-thruster operation with the PMS. These sub-system integration tests of the PMS, the DCIU Simulator, and multiple thrusters addressed, in part, the NEXT PMS and propulsion system performance and functionality requirements.
[1]
Michael J. Patterson,et al.
Power console development for NASA's electric propulsion outreach program
,
1993
.
[2]
John Steven Snyder,et al.
Environmental Testing of the NEXT PM1 Ion Engine
,
2013
.
[3]
Michael J. Patterson,et al.
NEXT Ion Engine 2000 Hour Wear Test Results
,
2004
.
[4]
John R. Brophy,et al.
Dawn Ion Propulsion System - Initial Checkout After Launch
,
2008
.
[5]
Fred Wilson,et al.
Overview of the NEXT Ion Propulsion System Program at Aerojet
,
2005
.
[6]
Michael J. Patterson,et al.
NEXT Ion Thruster Performance Dispersion Analyses
,
2007
.
[7]
Michael J. Patterson,et al.
NEXT Ion Propulsion System Progress Towards Technology Readiness
,
2008
.
[8]
Michael J. Patterson,et al.
NEXT Multi-Thruster Array Test - Engineering Demonstration
,
2006
.
[9]
Andrew Hoskins,et al.
Development of a Prototype Model Ion Thruster for the NEXT System
,
2004
.
[10]
Michael J. Patterson,et al.
Performance Evaluation of the NEXT Ion Engine
,
2003
.
[11]
Michael J. Patterson,et al.
Demonstration of the NSTAR ion propulsion system on the Deep Space One mission
,
2001
.
[12]
Michael J. Patterson,et al.
Space Station Cathode Design, Performance, and Operating Specifications
,
1998
.
[13]
Michael J. Patterson,et al.
NEXT Ion Propulsion System Development Status and Performance
,
2007
.
[14]
Fred Wilson,et al.
Development Status of the NEXT Propellant Management System
,
2004
.
[15]
Nicole J. Meckel,et al.
NEXT Ion Propulsion System Production Readiness
,
2007
.
[16]
Michael J. Patterson,et al.
NEXT Single String Integration Test Results
,
2009
.
[17]
Michael J. Patterson,et al.
Performance Evaluation of the Prototype-Model NEXT Ion Thruster
,
2007
.