As time goes by and mankind's semi-permanent residency in microgravity
enters its second decade, thoughts turn to the logistics of permanent
residency in space habitats. Once cannot be self-sufficient anywhere
without producing one's own food. Currently the ISS is totally supplied
from the ground, and a great deal of effort has gone into selecting
foodstuffs which are resistant to spoilage, easy to eat and need minimal
preparation given the still rather primitive facilities aboard the
station. Chris Hadfield's recent extremely popular videos show that space
food is roughly equivalent to camping food:
<
http://www.youtube.com/watch?v=AZx0RIV0wss"> bagged,
<
http://www.youtube.com/watch?v=P5FuPC6nsH0"> dehydrated,
<
http://www.youtube.com/watch?v=7ZnUSoa5p6s"> pouched,
<"
http://www.youtube.com/watch?v=EtaWWCXbtbY"> tinned,
<
http://www.youtube.com/watch?v=W1lkeM6YoqU"> tubed and boxed.
All of these items must be produced on Earth and flown up to the station.
But how is a permanent, self-sufficient facility going to cope with the
tasks of preparing food from raw ingredients? How do you crack an egg into
a bowl of water and add flour to make your tortillas? How do you peel and
chop an onion without little flecks of onion skin and juice getting all
over everywhere? How do you fry your pancakes? How do you roast your meat?
Steaming vegetables is fairly easy. Using solar heat to boil water is
trivial. Pumping the steam into an enclosed cooking vessel is equally
trivial, so steamed vegetables will likely become a staple of our
habitat's inhabitants' diet. Perhaps even steamed dumplings with meat or
bean fillings such as are extremely popular in China could be done with
little difficulty (assuming the problem of mixing up the dough is solved).
I imagine that steaming will replace boiling as the best and most
efficient cooking method.
Roasting is not terribly difficult. Assuming the availability of an
enclosed toaster-oven like structure, one could impale their piece of meat
on a skewer which would then anchor in place inside the oven, and probably
turn to revolve the meat past the heat source(s). The drips would be dealt
with through a small convection fan equipped with a grease trap. Problems
arise with the prospect of cutting the roast after it's cooked and dealing
with the inevitable juices which accompany roast beast. It may be likely
that roasted meats will be extremely rare. A more manageable meal would be
shish-kabab, alternating meats, mushrooms and vegetable chunks threaded on
the skewers and roasted. The skewer would be anchored to the eating
surface and each chunk taken off individually to be eaten. Even if you
can't use a traditional dry heat oven, microwave ovens have been around
for long enough that everyone knows how to use them. They're compact,
simple to use and put much less of a burden on the station's electrical
power.
Barbecue is likely impossible. For one thing, there's no back yard in a
space station, open flames behave very strangely in microgravity and that
doesn't get near the problem of keeping the charcoal contained and the
food on the grille. An important component of barbecuing is the drips of
fat and sauces which fall onto the coals and burn, flavouring the food. In
microgravity that won't happen. Barbecue is a pleasure reserved for
gravity.
Frying presents huge challenges. How do you get your pork chop to stay on
the frying pan? Once your egg is cracked, how do you put it on the pan?
Indeed, how do you get it out of its shell in the first place? How do you
keep yourself from floating into contact with the pan and burning
yourself? One possible method to solve the adherence and safety problems
is to enclose your frying pan in a centrifuge so that it may spin to mimic
gravity. The pan would have to tilt as the spin accelerates, to prevent
whatever is frying from sliding off the outside edge. It may even be a
good idea to put a rim and lid on the pan to keep everything within.
Ideally there would be two pans rotating in opposite directions to counter
the effects of torque. The speed of rotation would depend on the viscosity
of whatever is being cooked. Pancake batter is fairly thick, and so would
only need a relatively slow spin. The pork chop would need something
approaching one g in order to cook properly. You'd have to stop the spin
halfway through cooking so you can flip the food over and cook the other
side.
And how do you get your pancake mixed in the first place? Flour is exactly
the wrong thing to have floating loose about your pantry and getting into
literally everywhere so it would need to be contained at all times. And
how do you persuade it to sit in the measuring cup so you know that you've
scooped out enough for your recipe? Mixing solids and liquids in
microgravity is an entirely different prospect than it is here on Earth.
Open bowls are completely unsatisfactory, as are electric mixers which
would only serve to spread partially-mixed blobs of dough over every
available surface in the galley, including the cooks. Currently, dry
powders are mixed with water in plastic pouches. The water is injected
(hot or cold as necessary) into the pouch and the contents kneaded
together until the mixing is complete. This works well in the short term,
but plastic does not last forever and it won't be long until our kneading
bags are wrinkled, worn and ready to tear at the worst possible moment.
And how do you get the previous mixture out of the bag when you want to
mix up something else? Supplies of washing water are limited and in any
case what do you use for a sink? Another bag? A watertight glove box?
Ultrasonics? Exposure to vacuum and then flaking off the dried bits
remaining?
And that brings up doing the cleanup after the cooking is finished. Doing
the dishes in space is yet another chore which will have to be re-
invented. It's a bonus that you're unlikely to drop a plate on your toes,
but washing things in batches by hand as it is done here on Earth will be
prohibitive given the need to constantly keep everything tethered or
controlled. Washing one piece at a time is a great way to spend far more
time than there is in a day. Dishwashers would work in a similar manner as
they do in a gravity field, except for the need to vacuum out the washing
water when the cycle is finished but once again that presumes that there
will be sufficient water available to use for such tasks. You must take
care in loading and unloading. A glass won't drop on your foot if you let
it go, but it may fly away and smash against the far bulkhead instead.
Speaking of pork chops and roast beasts, they're actually pretty unlikely
foods to be produced in space. Animal husbandry is yet another field of
endeavour which will need to be re-invented. Farming in microgravity would
be difficult. Keeping the animals healthy so they grow properly would be a
more than full-time task, and that presumes that they'll adapt and learn
to feed themselves. It's much more likely that meat produced in space
would be from smaller animals such as rabbits, fish, guinea pigs and the
like. Birds may adapt well to microgravity, so chicken could likely be a
large part of the menu or the current experiments in growing tissue in
vitro may pay off and avoid the necessity of dealing with animals at all,
except in the abstract.
There, that ought to be enough to spark off a good discussion. Thoughts
anyone?