→ L-355: Mass measurement

Some more Soyuz manual flying today and then a class dedicated to Russian medical equipment on Soyuz and on Station.

When we fly on the Soyuz we wear a medical telemetry belt with sensors that can measure our electrocardiogram and our frequency of breathing: it’s actually the same belt that I’ve worn several times during underwater Orlan training in the Hydrolab.

As for the Station, the one item in the Russian segment that I will be using regularly is the body mass measurement device. Since we can not use regular scales to measure our body mass in weightlessness, we had to get creative and dig into the physics books to find a physical relationship that is still valid in zero-G and allows us to measure mass.

Here’s where your oscillator formulas come in handy. It’s actually pretty straightforward: if you oscillate a mass attached at the end of a spring, the frequency of the oscillation is related to the mass via a well known equation. So if YOU are the mass that is oscillating, there you go: you measure the frequency of oscillation and you’ll know if you’ve been eating too many of those delicious space food pouches!

In the photo you can see Tom Marshburn using the mass measuring device (photo: NASA).
Here’s also a neat video demo with detailed explanation by Jeff Williams: