Sunday 5 September 1999 9.00pm EST
|During the last 48 hours a series of HRC-S focus measurements were completed successfuly. Measurements included a series of shutter scans that provided focus centroid data. The CXC science team completed analysis of the data and provided the new SIM position for HRC-S in focus in preparation for the deployment of the Low Energy Transmission Grating (LETG).
The LETG deployment procedure was conducted between 6PM and 9PM on 9/5 and the team successfully released both launch locks and inserted the LETG with HRC-S in the focus position. The science team confirmed that data from Capella looks good and that initial assessment indicates that the LETG is functioning as expected. Great news that the final mechanism has been deployed on Chandra! The LETG will be left inserted for 11 hours and then retracted via hardware command.
A telecon was held to discuss the observed B-side voltage during HETG insertion and retractions. The decision was made to continue with the LETG deployment and set a relay to allow monitoring of B-side telemetry during insertion and retraction. Expectations were that simlar voltage (probably caused by back-EMF) would be seen with LETG. This was confirmed during the procedure with a value of 6.9 volts compared with 6.0 volts seen with HETG. Further analysis will continue to confirm that the voltage is due to back-EMF.
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