Power Interruption Today

The SDO.gsfc.nasa.gov website will be unavailable today from 7:00 am - noon ET while work on the electrical supply to the building takes place.

Station Keeping Maneuver #17 is Today

SDO will perform Station Keeping (or Delta-V) Maneuver #17 today between 2200-2250 UTC (6:00-6:50 p.m. ET). This maneuver is used to keep SDO inside its box in the geosynchronous belt. SDO thrusters will expel 82 grams of propellant to complete the maneuver.

During the maneuver science data may be missing or blurry.

Comet Offpoint Test Looked Great!

The comet offpoint test SDO ran very smoothly yesterday. Here is an AIA 171 Å image from 1441 UTC (10:41 am ET). The image of the Sun has been shifted back to the middle of the frame so the offpoint doesn't look so jarring in the daily movies.

If this had been a real comet observation the scientists would want to examine the missing right-hand side for the comet tail. AIA 171 Å was our best channel for looking at the comets.

My thanks to the SDO Flight Operations Team for making the test look easy.

Comet Offpoint Test, August 8, 2018

Tomorrow morning, from 1430-1505 UTC (10:30-11:05 ET), SDO will perform a comet offprint test maneuver. This is only a test, there is no comet that will be visible. However, it has been almost 6 years since we performed such a maneuver and its good to keep in practice. We only get a day or two notice when a Kreutz sun-grazing comet might be visible. This test allows us to put the instructions in a easy to access location for the next comet.

The Sun will appear to shift to the left during the test. That means it is useful for Kreutz comets in July and August, when the comets appear to come from the right and pass across the face of the Sun. Some science data, such as magnetograms and Dopplergrams, will not be produced while the Sun is shifted from the center of the images.

When a sun-grazing comet arrives, we will be ready to go comet watching!