Solar Panels and a Battery for Providing Power Supply
Electrical power is provided by the spacecraft's solar panels, which are
folded against its body during launch and deploy shortly after the launch
vehicle housing has been jettisoned. The panels are mounted on a drive
mechanism that tilts them forward and backward to catch most
sunlight. Their surface area is 11 square meters (118 square feet), which is
larger than those used on near-Earth orbiting satellites to compensate
for the drop in sunlight intensity at Mars.
When the spacecraft's view of the Sun is obscured during a solar
eclipse, an innovative lithium-ion battery, previously charged up by the solar
panels, will take over the power supply. They are important as some
1,400 eclipses, lasting up to 90 minutes, are expected during the primary
mission's lifetime. Eclipses occur when the spacecraft is in polar orbit
around Mars and its view of the Sun is obscured. When Mars is at its
maximum distance from the Sun, the solar panels will be capable of
delivering 650 Watts which is more than enough to meet the mission's
maximum requirement of 500 Watts.