All you ever wanted to know about waste trays and more

Somebody in Payloads is watching out for you! Last week I was sitting at my desk answering email when the phone rang. It was Chris Barreras (our in-house expert on the Great Habitat Debate) and his comment was, "We're assembling the RAHF waste trays right now in the HiBay and it seems like a NeurOn-type activity. Would you like to come watch?" Would I! I dropped everything, grabbed the digital camera and followed Chris' instructions to find the HiBay.

My first clue that I was entering something special was the super-sticky floor mat I had to step on to clean my shoes at the pass-protected door. What I entered was a room that was, for all the activities taking place in it, remarkably clean and organized. It's called HiBay due to the hangar-like high ceilings and looks a lot like one of those warehouses you see on TV, but those are usually dark and you can expect something awful to be lurking somewhere. Hibay, on the other hand is brightly lit and everyone in there is dressed in white. I felt like I had been invited into the inner sanctum!

That, of course, was one of the first things I had to do. Chris instructed me to put down all my tourist-like paraphernalia (don't worry I got to take pictures and will share them with you below) and don a white smock. Chris had gloves on, but since I had no intention of touching anything those weren't necessary for me. I was then introduced to Lorenzo Salcedo, the wizard of waste trays.

Now those of you who designed habitats for the Great Habitat Debate and participated in the chats with Mary Williams and Chris Barreras probably have some ideas about the make-up of an RAHF waste tray, but I know I had no idea how complex they really are! For those of you who are new to this dialog, here's a question that was raised in the chat with Mary: How do you keep the animals for the microgravity experiments clean? I imagine that floating excrement would not be good for them. Mary's answer was: The cage systems have fans that gently blow from the top of the cage into a waste tray at the bottom. This keeps most of the excrement from floating around in the cage.

These chats led people to redesign their waste handling systems, but none really included ALL the elements of the RAHF waste tray. So here goes: I'll try to duplicate what Lorenzo demonstrated with pictures!

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	The waste tray itself consists of two light colored plastic frames that corresponds in size to the length of the RAHF habitats. The lower housing or frame is filled with a wire screen upon which Lorenzo had already placed a "filtrete" which looks a lot like a thin sheet of cotton secured in place with red RTV sealant.
	By the time I arrived, these had been drying for 12 hours lined up on a table.
	The first step I observed was the placing of a thin charcoal filter across the surface of the filtrete (again secured in place with sealant.
	Into the other "frame," which had a plastic, more open mesh, Lorenzo placed Bondina, a thicker, white cushion.
	The two frames (or sides of the "sandwich", as Lorenzo called it) were then put together, indeed much like a sandwich and screwed in place.
	The next step was the "horseshoe." Again I didn't touch it, so the best I can tell you was that it looked like stiff white plastic sheeting in the shape of a horseshoe.
	Lorenzo coated a side with Tepelon, and then screwed it in place around the waste tray. My understanding is that this horseshoe helps to guide the tray into place in the habitat.
	Then Ta-dah! Lorenzo held up the final product and smiled. As he worked, he had told me that he was awaiting hopefully the day when this whole unit will be made disposable. You see, not only does he get to put these together, but upon return from flight, he gets to pull them apart for cleaning! Ughhhh!