Wednesday, June 19, 2013

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.
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.