From the Stratosphere

The team arrived at the launch location before dawn so they could photograph the Earth in beautiful morning light. The lower layer of the stratosphere, at an altitude of 10–20 km (6.2–12.4 miles) above Earth’s surface, can reach temperatures as low as -55° C (-67° F).

That can damage camera batteries, and lenses can get misted over or covered with ice crystals, so these cameras had to be specially prepared to operate in extremely cold temperatures.

Assembling the cameras required a lot of attention. They needed to have several GPS beacons attached to them so they could be found after they returned to Earth. Also, the balloon had to be inflated, and the cameras securely attached.

With the sun just below the horizon, the crew launched the balloon. A team member filmed it from a radio-controlled model airplane as it sailed slowly into the troposphere above the rolling fog.

Almost everything we think of as “weather”—wind, storms and violent events like hurricanes and cyclones—takes place in the troposphere. And the troposphere is where clouds gather. The good news was that, on this morning, the air was calm, and just a few thin clouds wafted above.

The balloon’s rising into a blue sky. Why not green? Sunlight has a full spectrum of colors, each traveling at different wavelengths. The atmosphere is filled with gases, mainly nitrogen and oxygen, which the light passes through.

Since the gas molecules are closer in size to the shorter wavelengths of light at the blue-indigo-violet end of the spectrum, they scatter and reflect that light most effectively. And, human eyes are more sensitive to blue and indigo light than violet.

The balloon has reached an altitude of 37 km (23 miles). Look down through the clouds and see forests, fields and Pleshcheyevo Lake. Look around and see stars, including the one at the center of our solar system.

Why don’t the bright sun and stars fill the blackness of space with light? In space, there are so few molecules that the scattering of light doesn’t occur. Light passes through in a straight line, and all we see is a void.

Our sun is slowly collapsing inward. The pressure at the core is so great, nuclear fusion occurs, converting hydrogen to helium, generating enormous energy. Some of that energy travels through space to us via photons—light—in a trip taking 8 minutes.

What happens as something rises through the atmosphere? The higher you go, the less atmosphere there is pressing down, and the atmosphere itself is “thinner”—it has less and less matter in it and therefore less weight.

The balloon is made of a flexible material filled with helium. As the air pressure on the balloon decreases the helium molecules spread out. This balloon has been expanding throughout its entire ascent, finally reaching the size of a 3-story house. And then?

The balloon was meant to pop. The cameras it carried descended to Earth on parachutes. The GPS devices on the cameras sent coordinates from several kilometers above the ground and transmitted coordinates from their landing positions, where they were retrieved.