Space Wombats and Penguin Poop: Spying on Animals from Orbit

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Penguin Spotting, and Other Cool Satellite Tricks

You’d be surprised what you can see from 300 miles up

For Smithsonian Air & Space Magazine:

At first glance the picture might be an abstract oil painting or, less artistically, poppy seeds scattered on cream cheese. The “cheese” in this case is a field of ice off the coast of Antarctica, and the black seeds are emperor penguins. The photo was taken from space, and is a good example of how satellite imagery is helping biologists study wildlife populations in new ways. No scientist needed to set foot near the penguin colony or fly an airplane overhead: High-resolution images from an orbiting QuickBird satellite were good enough to monitor the colony’s health over time.

“The advent of remote sensing allows us basically to see some of these areas that you physically cannot get to, no matter how hard you try,” says Michelle LaRue of the University of Minnesota. She and her colleagues use high-resolution images purchased from DigitalGlobe, Inc., one of a few private companies that license satellite imagery to governments and academic researchers. Other scientists use free satellite images from Landsat and other government-run programs. Although those tend to be lower in resolution, they demonstrate how remote sensing is important for the literal big picture: The huge areas of land surveyed by satellite make possible research that couldn’t be done otherwise. That’s true whether the location is (like Antarctica) hard to get to, in a conflict zone, heavily populated, or just too darn big.

[Read the rest at Smithsonian Air & Space Magazine…]

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In a certain sense, it’s easy to keep things in orbit around Earth. However, it’s hard to keep satellites in a specific orbit, which is what matters most for communicating with them and they with us, whatever task they’re designed to perform. Thanks to the work of rocket engineer Yvonne Brill in the early 1970s, the process is remarkably automatic.

Brill’s design eliminated this redundancy and lightened the spacecraft in the process. She also used a type of fuel called hydrazine, which is so reactive you don’t need oxygen or another chemical injection to ignite it. (On Earth, we’ve got lots of oxygen available for making things burn, but in space, you need to carry your own fuel for fire.) Brill’s system pumped liquid hydrazine through an aluminum nozzle. The chemical composition of the nozzle reacted with it, splitting it into smaller molecules and releasing a lot of energy. [Read more…]

I’m no rocket scientist, but I can appreciate the challenges of engineering something that needs to stay in the same orbit for years or decades. Yet the New York Times obituary for Brill mentioned her remarkable achievements as a sort of afterthought, as though they weren’t very important, really, in the scheme of things. My piece isn’t an obituary—I mostly write explanatory pieces about science, after all—but Brill’s contribution to spaceflight in general and the communications satellite revolution of the 1980s is astounding.

Yvonne Brill and the technology keeping satellites in orbit