Space Forum / Space Science / September 2005

No, they went back to Earth time quite a while back (I think it was at the
end of the 90-day primary mission).  Living on Mars time was convenient
for getting the most out of the rovers, but it was hard on the people to
be out of sync with the world they live in.  When the rovers' lives were
expected to be short, it made sense, but when it became clear that rover
operations might go on for quite a while, they had to change to more
sustainable working practices.

It's not as big a problem as you might think.  The bulk data transmission
goes via the various Mars orbiters, and there are only a few orbiter
passes per day.  They're more or less running the rovers by email:  they
send up some orders, and some hours later, maybe even the next day if the
timing doesn't work out right, pictures (and other data) come back showing
the results.  People aren't sitting around watching the results roll in
minute by minute; the pace is more relaxed.  So being on Earth time means
occasional delays when the schedules don't line up well -- e.g., the next
batch of pictures comes in after people have gone to bed -- but that just
means the rover sits and waits for orders a bit longer than usual.