The Power of the Solar Arrays Recently, one of our fans on the
NASAJPL Facebook page asked a good question about the efficiency
of solar arrays on the Dawn and Rosetta spacecraft. “A question
about Dr. Marc D. Rayman’s comment in his Dawn journal, saying
that ‘its tremendous solar arrays [are] the most powerful ever
used on an interplanetary mission.’ Is that really true?
According to JPL’s Dawn website, the solar arrays have a total
span of 19.7 meters. By comparison, each of Rosetta’s two arrays
is 14 meters in length (28m total). Are Dawn’s arrays so much
more efficient? Thanks.” Here’s an answer from Dawn Chief
Engineer Marc Rayman: Yes, this is really true. Dawn’s solar
arrays, although smaller than Rosetta’s, could indeed produce
more power because they are more efficient. Fortunately, it is
not a competition! Both missions seek fascinating new insights
into the complex history and character of the solar system as
they take all of us on adventures to exotic destinations. To
overcome some of the daunting