May 17 1970
From The Space Library
Sert II (Space Electric Rocket Test), launched Feb. 3, had reached halfway point of six-month endurance test in space with ion engine operating satisfactorily for more than 2000 hrs, NASA announced. Experiment to determine whether electric rocket operation would interfere with radio communications between spacecraft, electric propulsion system, and nearby space indicated there would be no problem. Experiment to measure effects of ion thruster efflux on silicon-cell solar array showed solar cells were being adversely affected. As ions were emitted through molybdenum grid, small particles of grid broke off (sputtered) and were deposited on nearby surfaces, reducing ability of test patches to convert solar energy into electric power. Controllers had turned off electric bombardment engine for several hours March 7 to avoid damage during solar eclipse when Sert II intersected eclipse path on two orbits with sharp loss in electric power from solar cells. After engine was restarted it continued to function satisfactorily. Only problem had been Feb. 7 failure of miniature electrostatic accelerometer, one of four methods of measuring engine's thrust. (NASA Release 70-69)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
