Why aren there any LASCO data for the dates mm/dd/yy to mm/dd/yy ?
SOHO uses its thrusters every few months to maintain its orbit and pointing. The flight operations team has to prepare very carefully for these operations since there are many checks and much data analysis required to make sure the thrusters fired properly and the spacecraft attitude and systems are operating correctly before and after the thruster firing. It is not lightly rescheduled since the orbit and thruster calculations would need to be redone. During that time LASCO and other SOHO instruments close their doors to prevent exhaust from the thrusters reaching their optics. We do calibration images (dark images , calibration lamp images or calibration opal ) or no image taking at all when our doors are closed. Thruster firings (somtimes noted as momentum management) are noted in the daily status reports and typically will take several days as the flight operations team analyzes the ranging data and does other measurements to make sure everything is okay. EIT does not close its door
