Nuts and Volts - September 2007

■ FIGURE 13. My highest altitude photog (near 87,000 feet).

It was a hazy morning over Nebraska, as you can see. at end of this month’s column); and the last, a cube covered in MLI and a black jacket of construction paper. As you can see, they cooled close to the same rate initially. But as they neared the stratosphere after 35 minutes of flight, their temperatures deviated widely from one another. At balloon burst ( 83 minutes into the mission), they chilled to nearly the same temperature after 10 minutes.

THE GREAT PLAINS SUPER LAUNCH OF 2007

The largest amateur radio, high altitude balloon (ARHAB) event is the Great Plains Super Launch (GPSL). Eleven weather balloons were launched on July 7th in Grand Island, NE, the location of GPSL 2007. The Central Nebraska Near Space Project (CNNSP) hosted the two-day conference this year in their home town. Friday was spent in discussions, with several near space groups giving presentations on the art and science of their near space programs. There were discussions on air density and its effect on a balloon’s coefficient of drag, flight computers, balloon release mechanisms, and meteorology.

Along with the presentations there was lots of socializing, especially over lunch and dinner. The new attendees were presented with a ton of information. One of this year’s sponsors was Nuts & Volts Magazine (thanks guys). But the best was Saturday morning. That’s when we filled and launched our near spacecraft.

DePauw and Taylor Universities were there along with amateur groups from Kansas, Nebraska, Idaho, Colorado, Oklahoma, and Maine. The balloon filling took place early in the morning so the balloons could be launched before the surface winds picked up.

For additional insurance though, we filled the balloons behind a row of organic wind blockers (otherwise known as tall trees in Nebraska). I really have to hand it to Roger and CNNSP for the great job they did finding a conference center and launch site. Figure 13 shows a photograph from GPSL 2007.

Every near spacecraft was recovered after they landed except for one. We lost contact with its tracking capsule shortly after lift off. I had to leave for Idaho just after lunch

BRIEF NOTE ABOUT MULTILAYER

INSULATION (MLI)

One of the best insulators is the Dewar flask (which is the same thing as a thermos bottle). Usually though, spacecraft cannot carry a glass thermos to insulate themselves. So they’re covered in a fabric version of this called MLI. I make my MLI with three alternating layers of space blanket (aluminized Mylar) and scrim (plastic wedding veil material). In a good hard vacuum, this stuff will work great. But in near space with its near vacuum, it’s not nearly as effective. But it still beats launching a glass thermos bottle on a balloon.

NEAR SPACE

on Saturday, but most of the groups stayed around for an informal dinner on Saturday evening. I hear this dinner was very successful and will be included in GPSLs in the future.

There’s one more super launch planned for this year and several for 2008. The next GPSL will be held by Near Space Ventures in Kansas City, MO. You can find the date and other information at the Super Launch website at http://superlaunch.org. I hope to see you next year at one of the super launches.