EVE Cruciform on July 17, Other Maneuvers this week

When you see the Sun zipping through the SDO movies you know its time for a calibration maneuver. Last Wednesday we did an EVE cruciform, nodding SDO up, down, back, and forth to allow EVE to look at how the instrument is behaving. The blurry frame on at left is an example of what happens when you take an AIA 171 image during one of the moves. This Wednesday we will do an EVE field of view and HMI/AIA flatfield. Although we can't maintain our 24/7 observing schedule during these maneuvers, they allow us to keep the instruments in excellent shape.

Which Way is North?

Compasses tell us which way is North on the Earth. It's easy, the needle with the big N points toward the North Pole of the Earth. Other directions can be read off the dial, like a primitive GPS!
Compasses work because the Earth has a simple magnetic field with the magnetic poles in almost the same place as the rotation poles. And the compass needle points along only the part of the magnetic field that is horizontal.
The Sun also rotates and has North and South poles. But compasses aren't very useful on the Sun. The solar magnetic field is very complicated and is usually vertical rather than horizontal. Now North and South refer to magnetic fields pointing out of and into the surface.
In an HMI magnetogram (such as one from July 15, 2013 on the left) we color the outward pointing fields as white and inward as black. The weak fields are grey.
So it is probably better to think of the solar field as outward (+) and inward (-) rather than North and South. That way you won't use the magnetic field to give directions on the surface of the Sun.
On the Sun it isn’t which way is North, but which way is up!

Space Weather on Brewster Rockit

Check out the July 7 Brewster Rockit, a comic at GoComics.com. A nice little illustration about space weather effects in the heliosphere. A bit of a preview is at left.

LMSAL JSOC Computers Shutting Down Today

Maintenance on the chillers in the building hosting the SDO JSOC computers at LMSAL means those computers have been turned off. The main JSOC archives at Stanford are unaffected and this temporary shutdown should not affect users.

So Long Camilla

Little SDO is looking a little sad today. His long time partner in EPO, Camilla Corona SDO has retired as the SDO mascot. Camilla had an great career as a mascot, traveling to the stratosphere and many other places to bring the excitement of science to audiences of all ages. She made young children understand that science starts when you ask questions.
Good luck in your new life as Camilla Corona the Space Chicken!

Where is SDO?

SDO is in a 28 degree inclined geosynchronous orbit, 36,000 km above Earth's surface. Unlike a satellite in geostationary orbit, which appears to just hover above Earth, SDO actually traces a figure-8 in the sky every day to have a direct line of sight to White Sands, New Mexico, where the two dedicated ground stations are located.

You can always check in and see where SDO currently is here: http://sdo.gsfc.nasa.gov/mission/moc.php

How long did it take to plan and design SDO?

It took a little over 10 years to plan and design SDO. More information the multi-phase process below.

SDO Mission Milestones

Pre-Phase A- 1997 - After the launch of the Solar & Heliospheric Observatory (SOHO) in 1995, solar scientists began thinking about what data they were still lacking that was necessary to do the science that they wanted to do. From this needs assessment and based on lessons-learned from the SOHO build, launch and data they began to develop the preliminary ideas for the next Heliophysics strategic mission. For the SDO, Lockheed Martin, Solar and Astrophysics Laboratory was selected to build and operate the Atmospheric Imaging Assembly (AIA), and to build the Helioseismic and Magnetic Imager (HMI). HMI would be operated and the huge data stream (~4 TB per day) managed at Stanford University, while the University of Colorado, Boulder would build and operate the Extreme Ultraviolet Variability Experiment (EVE).

Phase A- 2002- The deliverable at the end of Phase A is System Concept Study report which contains, more specific instrument requirements, a more complete budget. 

Phase B- 2003- During Phase B, the preliminary plan is converted into a baseline technical solution - requirements are further defined, schedules are determined, and specifications are prepared to initiate system design and development. The deliverable at the end of the phase is the Preliminary Design review document, which sets out very specific requirements for the build and testing of the instruments down to how many threads a bolt will have, and the exact pressure that will be used to attach said bolt.

Phase C and D- Build, Integration and Testing- 2004

Phase C represents the beginning of the implementation stage. The Phase C deliverable is the Critical Design Review

 There is a lot of activity in Phase C including:

·      Procurement of all aspects of the space craft

o   Announcements of opportunity go out in 2005 for technical aspects of the space craft.  These announcements unlike the instrument announcements contain of the design and technical specifications required.

o   Manpower profile peak- All manners of engineers are modeling, building and testing every aspect of the spacecraft for various factors, operations, ability to withstand space, integration with other spacecraft instruments and bus.

o   HMI, EVE and AIA are built onsite at the subcontract locations

·      The Testing of all of the parts of the spacecraft in the thermal vacuum chambers and on the vibration tables to ensure that they are space ready.

Phase D Deliverable is the pre-ship review, and the completed and launched spacecraft.

·      At this point there is a comprehensive audit in which all of the procurements are matched up with budget items and check lists

Launch an initial commissioning takes place during phase D.

Phase E- Science mission and Operations- 2010

During Phase E science data is collected and made available to the public for scientific investigations that take place around the world. The mission is monitored 24 hours a day 7 days a week by the mission operations team at Goddard Space Flight Center. The instruments are monitored and operated at their respective institutions. To date SDO has met minimum mission success, meaning it has fulfilled all of the mission goals. It has taken over 100 million images of the sun and served 4500 terabytes of data.