Download or read book Radiometric Analysis from the 26 kW Electric Propulsion Space Experiment ESEX Flight written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Air Force Research Laboratory's Electric Propulsion Space Experiment (ESEX) was launched and operated in early 1999 in order to demonstrate the compatibility and readiness of a 30 kW class ammonia arcjet for satellite propulsion applications. As part of this flight, an array of on-board contamination sensors was used to assess the effect of the arcjet and other environments on the spacecraft. The sensors consisted of microbalances to measure material deposition, radiometers to assess material degradation due to thermal radiation, and solar cell segments to investigate solar array degradation. Over eight firings of the ESEX arcjet, (3 minutes, 26 seconds operating time) the radiometer near the thruster, viewing the arcjet plume and body, experienced a change in the thermal properties of its coating (repetitive) Radiometers with no view of the arcjet, or a view of only the plume, show no change. In general, contamination effects are observed only on sensors near the thruster exhaust nozzle, a location unlikely to be used in an operational high-power electric propulsion system. No contamination effects are observed in the backplane of the thruster. For future programs, while engineering measures may be needed for spacecraft equipment in the immediate vicinity of the thruster body, the arcjet environment is generally benign.

Download or read book Electric Propulsion Space Experiment ESEX Program written by Roger Metcalf Myers and published by . This book was released on 2002 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transcranielle Dopplersonographie nach aneurysmatisch bedingter Subarachnoidalblutung written by Thomas Vogtmann and published by . This book was released on 2002 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Contamination Electromagnetic and Optical Flight Measurement Development for the Electric Propulsion Space Experiment written by J. LeDuc and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Battery Failure on the Electric Propulsion Space Experiment ESEX written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The anomaly experienced on the USAF Electric Propulsion Space Experiment (ESEX) mission related to the silver-zinc battery is described. The on-orbit observations of the battery behavior in relationship to the thruster firings are summarized, as well as a description of the catastrophic failure which ended the ESEX mission. Although a final cause of the battery failure was not definitized, the data collected on-orbit, from ground tests, and from previous programs suggest a combination of effects that ultimately led to electrolyte leakage, and a subsequent short circuit between the battery cells and the case. The contributing effects likely include degradation of the mechanical interconnections between the cells, inadequate charge current, and excessive discharge current requirements. Lessons learned from the ESEX experience focus on the need for more realistic simulations of the on-orbit operations during ground test including the use of actual flight hardware and the associated timelines as much as possible.