Ed Lu’s Journal: Entry #12: Which Way is Up?

Last
week we had another Progress freighter arrive here (carrying
fresh food!), so this week has been occupied with unloading
and stowing away (or sometimes eating) the food, supplies,
and equipment. The freight compartment of the Progress is
roughly spherical and about 8 feet across, and is filled to
the gills with equipment in aluminum containers or bolted
to a metal framework. So to unload it we start near the hatch
and begin burrowing in, unbolting things and pulling them
out. The interesting part about working inside the Progress
is that there is no “up” or “down” direction
inside. There really isn’t an up or down anywhere else here,
but there is a direction we think of as the floor and a direction
we think of as the ceiling in each module. Most of the labeling
on panels and equipment is written so that it is right side
up assuming this orientation, and also most of the lights
are on the “ceiling” so they cast light “downwards.”
To add to the effect, there is a simulator back on Earth we
spent a lot of time in where we got used to one direction
as the floor and the opposite direction as the ceiling. So
up here, when Yuri and I say downwards or upwards, we mean
the equivalent directions as in the training module on Earth.

This
isn’t true for the Progress. Since it is just a cargo container,
we don’t have a simulator that we have trained in on the ground,
and since it is spherical there really isn’t a flat surface
to call the floor. So that means that work inside Progress
can be kind of disorienting. This is especially true if doing
close-up work on something (say unbolting a piece of equipment).
In weightlessness your body may shift position without you
realizing it while you are intently working, so that when
you pop your head back up after finishing you may find yourself
in a totally different orientation than when you started.
I recall looking out the hatch and being momentarily surprised
to see Yuri in the Service Module running on the treadmill
on the ceiling! Actually, it was me that had flipped upside
down. I’ve had the same feeling before while scuba diving
after looking down at something, then picking my head back
up to find that everything had moved!

It is
interesting how the same module can look like a completely
different place when viewed upside down. Every once in a while
here, I spend a few hours upside down just for fun, treating
the ceiling like the floor. The familiar modules don’t look
so familiar anymore. This is true even though I am completely
used to flipping my body around to whatever orientation needed
to work on things. In space you need to remember that you
aren’t limited like you are on the ground to having your feet
on the floor – they can just as easily be on the wall or on
the ceiling. I find that when I am working in a tight space,
I don’t really think about any particular direction as up
or down, but when out in an open space like in the middle
of a module I do. If for instance I am up on the ceiling,
by concentrating I can make myself think of the ceiling as
the floor. I really think it is a matter of just familiarity
what you call up or down. An example is the area around our
weightlifting exercise equipment, which is located on the
ceiling of the Node module. I’ve gotten so used to spending
time there in that orientation that I am more comfortable
there upside down. I’ve also gotten used to looking towards
the Service Module while I am working out and seeing Yuri
upside down – or at least the opposite way since from his
viewpoint – it is me that is upside down.

When
flying around, I’ve found that it is sometimes easiest to
think of which way to maneuver with respect to yourself, rather
than with respect to the module. This is the same trick you
have to learn when flying aerobatic maneuvers in airplanes;
you have to stop thinking about which way is up with respect
to the ground, and start thinking about which way to turn
the control stick so that you (and your airplane) turn the
direction you want. The reason, of course, for this is that
when upside down, the direction that was left now becomes
right. But if you think of it as turning towards your right
hand or left hand, then it doesn’t matter which way you are
oriented. Sometimes the whole world really does revolve around
you!

Which
way is up all depends on which way you look at it.

This picture
has nothing to do with the topic, I just thought it was a
neat picture. Last week the moon passed right by the planet
Mars (the red dot to the right of the moon). If you zoom in
on the picture you can see the polar ice caps of Mars. The
interesting thing about watching this was that I could watch
the moon appear to fly by Mars over the course of about 20
minutes. The reason, of course, was that the space station
was moving. The moon and Mars are also moving, but their motion
against the sky is fairly slow as seen from the Earth. So
that was a sight only visible from orbit!