Preparing the Beetle Activity Monitor

We recently found out that we need to get the drawings released for the Beetle Activity Monitor (BAM). That basically means that we need to get the drawings sent around for certain signatures to verify that a certain design is acceptable. If any changes need to be made it becomes a big deal, so you want to make sure you get it right the first time.

One of the things I was worried about, just by looking at the design, is the positive ventilation system that air is pumped into it. A positive ventilation system is a manual pump system used to ventilate the beetle habitats. Another item that we design engineers have to be aware of is the lack of convection air currents in the shuttle or MIR.

Convection is the movement of a gas or liquid due to a difference of density and weight. For example, warm air, because of its lower density and corresponding weight, rises through colder air in a room or the Earth's atmosphere. As the warmer air cools, it falls, thereby creating air currents. In an environment that lacks the effects of gravity, warm air has a lower density but not a weight difference compared to colder air. Therefore, the air does not move on its own.

The point of this long explanation is that we here on Earth get a lot of natural ventilation due to convection. In the case of our beetle experiment, since we could not rely on convection to provide natural ventilation we needed to include a mechanical ventilation system.

I was wondering where the air was actually going. So I just wanted to make sure that if we pumped air into the BAM, the ventilation would continue to work. I had one of my coworkers, who smokes cigarettes, blow smoke into the BAM to do a smoke simulation to figure out where the air was going.

You find that a lot of times you run through these little tests. Although there will be formal tests, you want to do these little tests to verify that something is working correctly. If I come up with a theory that there might be a problem with the ventilation in BAM, even though it might be better than I thought, it still may not be good enough. You come up with ideas that there may be problems and they must be tested for. Blowing smoke into the BAM was my quick and dirty test that verified I would have to make some changes.

You have to come up with a plan that tells what testing will be done. We don't produce large amounts of any of our hardware. Each part is different from the one just made. We have to come up with tests that are specific to each piece of hardware to make sure that they will work.

In my mind, the worst possible scenario is that we design something and send it up on the shuttle and it doesn't work. It's very expensive to get equipment in space. We want to be able to visually inspect equipment and verify that it is going to work. Then we must set up tests to make sure the equipment will function correctly or that it qualifies for use. So we must be able to come up with ideas for what kinds of testing to use, and write reports that explain exactly how the testing will be done.

If certain equipment does not work, instructions are probably given to astronauts or cosmonauts to work with the equipment to the best of their ability. For example, if anything were to break in the case holding the BAMs, we would not want the astronauts to open it. We would not want any of the particulates within the case to fly out.

Particulates are any small bits of debris, which can include dirt, metal or plastic flakes, and in the case of the beetles, feces. Containment of both odor (generally with filters) and particulates (with filters or screens) is a big concern in our hardware design. We on Earth live in a gravity environment. The type of particulates I'm talking about fall to the ground, but the astronauts are in a microgravity environment. Any loose particulates can float around the cabins and possibly be inhaled by the crew. Particulates could also irritate or injure a crew member's eyes.

The worst thing would be if the experiment is life threatening. With everything that we do, we try to make sure that the experiment is as safe as possible. The second worst thing that could happen is if equipment still does not work. In that kind of a situation there is not much more that the astronauts can do, but the experiment fails.