‘Lost’ Camera Records Stunning Footage From Edge Of Space

SCIENCE

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit.

Discussion Ideas

The footage from the edge of space was taken with a camera attached to a helium-filled weather balloon. How did the balloon rise so high in the atmosphere without any engine or mechanical liftoff device?
- Helium is lighter than air.
  - This just means that the helium gas molecules in the balloon have a lower density than the gas molecules that make up our atmosphere (dry air). Helium’s volume ratio compared to dry air is just 0.000005.

Watch the slow-motion replay of events starting at about 3:00 in the video. What is the substance that the New York Times describes as “white confetti against the darkness” of space?
- The confetti is remnants of the popped weather balloon.

So, why did the weather balloon pop?
- As altitude increases, atmospheric pressure drops. This is why, as you climb a mountain, you are literally climbing “into thin air.” Here’s a nice graph showing the relationship between atmospheric pressure and altitude.
- At an elevation of about 30 kilometers (98,660 feet), the pressure inside the weather balloon was so much greater than the pressure outside, it forced the elastic “skin” of the balloon to pop into white confetti.

The balloon climbed to nearly 100,000 feet in the atmosphere before popping. Take a look at this diagram of Earth’s atmospheric layers, or read our encyclopedic entry on the subject. What layers of the atmosphere did the camera document?
- First, you have to convert feet to miles (or kilometers). Luckily, the good folks at Google will do it for you! 100,000 feet is about 19 miles or 30 kilometers.
- The camera glides through the troposphere and the stratosphere. The troposphere is the lowest layer of the Earth’s atmosphere, extending from the surface to about 16 kilometers (10 miles) above. The stratosphere is above the troposphere, extending from 10 kilometers (6 miles) to 50 kilometers (31 miles) above the surface of the Earth.

How did the Stanford students lose their fancy weather balloon camera?
- The students were tracking the camera’s location using GPS, but their Earthbound smartphone (the GPS receiver) lost the signal. “The problem was that the coverage map we were relying on (looking at you, AT&T) was not accurate, so the phone never got signal as it came back to Earth, and we never heard from it,” said one student.
- Luckily, AT&T redeemed itself. “Two years later, in a twist of ironic fate, a woman who works at AT&T was on a hike one day and spotted our phone in the barren desert. She brings it to an AT&T store, and they identify my friend’s SIM card. We got the footage and data a few weeks later!”

Watch our introductory video on kiteography, in which a simple kite—not a helium weather balloon—is launched over the landscape. Why is kiteography a little safer and easier than balloon-ography?
- Conducting an experiment with high-flying weather balloons is potentially more dangerous and requires a little more prep work.
  - Watch the beginning of the video to see the Stanford students conduct flight preparations including a parachute drop test, trajectory planning, engineering a structure to safely and efficiently hold the camera, and use a 3-D printer to make the chassis.
  - To avoid endangering the skies and your legal record, balloon-ography also requires clearing your project with the Feds. In the United States, there are two sets of regulations governing launching and tracking high-altitude weather balloons. One is from the Federal Communications Commission (FCC) and the other is from the Federal Aviation Administration (FAA). Says one of the students who did the Grand Canyon experiment: “(I)t could be potentially dangerous for pilots and other aircraft. We registered with the FAA and let them know our desired time, location of launch, and the balloon’s predicted trajectory ahead of time. They responded back with a location and time window in which we could launch our balloon.”