Stephen Hawking celebrated his 75th birthday on January 8th, 2017. In celebration, we launched a near space mission and would like to share video link.
At the altitude the balloon bursts, the air pressure is 98% vacuum. Also, the distance to the horizon is 372 miles. The launch took place on the border of Idaho and Oregon, so the video is showing parts of Nevada, California, Washington, and Utah along with most of Idaho and Oregon.
During the video, you'll see that the party balloons expand because of the reduced air pressure at altitude. As chemistry and physics students will recall, this is a result of Boyle's Law (1660). Robert Boyle's work influenced Isaac Newton and it turns out, Stephen Hawking and Isaac Newton held the same chair at Trinity College (the Lucasian Professor of Mathematics).
The following article from Outside Magazine reported on one of the design considerations for a record player in near space. To test the concern that a black sheet of vinyl will melt in near space, the following BalloonSat was built. The results of the test demonstrated that a phonograph record does not melt when exposed to the sun in near space.