Friday, August 7, 2009

Shout, Shake, and Bake: SDO Finishes Endurance Testing

"With a successful functional test, SDO has successfully completed the critical 'shout, shake, and bake' tests," said Solar Dynamics Observatory (SDO) Project Scientist Dr. Dean Pesnell.

Testing began in February and included a one-minute acoustical test (shout), a vibration test (shake), and an extreme temperature test (bake).

"We want to test all the conditions that SDO will see during its launch and operations," said SDO Observatory Manager Dr. Brent Robertson. "During launch, SDO must withstand enormous vibrations, jarring shocks, and blasts of noise. In orbit SDO will be exposed to extremes of hot and cold."

SDO began the final tests of intense heat and circuit-chilling cold in July and finished them on August 17, 2008.

"SDO spent about 12 days in thermal balance," said SDO Integration and Test Manager David Amason.

This test subjects SDO first to intense heat and then to extreme cold to see how it affects the spacecraft's temperature. Once SDO settles into geosynchronous orbit around Earth, the observatory will most often be in direct sunlight but occasionally will be in the cold environment of the Earth's shadow. After testing the sun-focused spacecraft at these temperature extremes to see how hot or cold it gets, "we then ran thermal vacuum," said Amason. "We ran SDO through three cycles of hot and cold to see how the spacecraft performs," Amason added.

The 19 days of thermal-vac testing were the last major step for SDO before it ships to Florida for launch. There, SDO will undergo another Comprehensive Performance Testing (CPT), have its flight batteries installed, get fueled up for launch, and meet up with the launch vehicle. So far, it looks like a go for SDO.