In orbit, the Leonardo module is for me a special place. It is cool, quiet, soothing—a good place to reflect and recharge. But like most closets on Earth, the PMM is a total mess. The crew is so busy maintaining and utilizing space station that no one has time to properly arrange things, despite our good intentions. A typical clutter-creating scenario might go like this: Say you are in the middle of working on the station’s control system. Swapping out motherboards is a delicate task, akin to doing computer brain surgery. If you bend a pin while inserting a card, you can fry the whole works, and there are precious few spare parts. In the midst of this intensity your stomach starts rumbling, with the associated low blood sugar shakes. Your watch shows that you have been at this for hours without a break. So you fly over to Node 1 and dive into the module where the primary stocks are located, only to find that the pantry is down to vegetables and tofudibeast. You need meat and potatoes to keep going, so you float over to the PMM and pull out a new “meats in pouches” package. At the galley, you cut open a meat pouch, only to have a big bloop of gravy squirt out and make a mess. Reaching for the wipes, you discover that the last one had been dispensed to clean up the previous gravy squirt. Flying to PMA 1 (the connecting tunnel between the U.S. and Russian segments), where the hygiene supplies are kept, you find that the staging bag for dry wipes is empty. Once again you dive into the PMM, searching for the mother lode of dry wipes. You refill the PMA 1 staging bag, and clean up your mess.

All of these packages have a nine-digit bar code. We are required to log these in our inventory management system, but often the bar code reader does not work. For this case of 20 dry wipe packages and a meats-in-pouches package, you have to write down 189 alpha-numeric characters (without a mistake). These numbers must later be typed up in a crew note or called down to mission control. So you think, “I will do all this inventory paperwork later.”

That’s how the PMM gets to be a mess.

When spare moments present themselves, I will go into the PMM and straighten up the clutter. Floating among the bags undulating on their anchor chords, I have the sensation of scuba diving in a kelp bed thicket. Then I catch up on the inventory paperwork. With luck, I’m able to scribble down all those nine-digit bar code numbers correctly.

Don's blog also appears at airspacemag.com.