How Long Must I Listen?
All
our spacecraft are fairly bursting with data most of the
time about how they are doing and what they have discovered
around them. So the faster they can "talk" to us, the more
information we will be able to find out. One of the new
technologies we are testing on Deep Space 1 is a way to pack
more information into the signal that future spacecraft send
back to Earth. It
can take a long time or a short time to receive exactly the
same data. Click on this small picture of Jupiter's moon Io
to see how different the times can be:
We
use very large dish-like antennas to listen for signals from
our far-away spacecraft. Like a teacher with too many
students, we have quite a few spacecraft to keep track of,
and not very many antennas. So we can't expect one antenna
to spend all day or all night listening to just one
spacecraft.
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