Aperture Cover Closing

Problem

At end of observation, while putting equipment in stowed positions …

Aperture was closed while Shutter was at 90°. Aperture closed properly and seal inflated.

Shutter was brought down to park at 7°. Change in gravity vector caused the Aperture Cover to move slightly off the closed switch.

Secondary problem: Only one switch changed position. This caused a Safety Logic Fault.

Aperture Cover was physically in closed position. Interlock controls did not report Aperture Cover in closed position and prevented closing or opening Aperture Cover.

Recovery

Drive the Shutter back to high elevation. Gravity vector returned to normal condition when closing.

This allowed the Aperture Cover to shift slightly so that both closed switches can operate.

With Aperture Cover switches in correct position the Safety Logic Fault could be reset and Aperture opened.

Drive Shutter down to 7° with Aperture Cover open.

Close the Aperture Cover when shutter at bottom position.