BBC Focus

SPACE

ILLUSTRATION: MAGIC TORCH

The spacecraft
deploys dozens of
20km-long wires,
completing one
rotation an hour to
keep them taut through
centrifugal force

The wires are

positively charged

to 20,000V, and this

creates a ‘virtual sail’,

nearly the size of

Greater London

The positively

charged particles

in the solar wind are

repelled by the sail, and

their momentum is

transferred to the craft

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