The Edge of Sunshine |Tweet|The Edge of Sunshine Solar energy is
an abundant source of power for spacecraft navigating the inner
solar system. But how far away from our star can photovoltaics
work? January 8, 2002: Â Try this: Close your eyes for a moment
and imagine the International Space Station (ISS), sunlit and
gleaming as it circles our planet. What did it look like? The
lingering image in your mind is probably dominated by broad,
beautiful wings -- the station's awesome solar arrays. It's no
accident that solar panels dominate the station's profile. On
the ISS (as on the earth below) solar energy ultimately powers
everything that happens. Our Sun, a star named Sol, radiates
enormous power: a constant output of 4 x 1023 kilowatts (kW),
which is a 4 followed by 23 zeros! Photovoltaic cells, which
convert sunlight to electricity, need only intercept a tiny
fraction of that total to energize the station. Above: The
International Space Station in December, 2001. Credit: the crew
of STS-108. But not all spac