Cosmic Ray Balloon Flights at Snowmass-2001

1911-2001: 90th anniversary of discovery of cosmic rays

Organizers: Greg Snow (U. Nebraska), Jeff Wilkes (U. Washington)


As part of the outreach and education program at Snowmass-2001, a balloon flight re-enacting the 1911-12 flights by Victor Hess was conducted on Sunday, July 8, 2001.

Jeff Wilkes (University of Washington, Seattle), dressed in period costume and carrying a replica of the instrument used by Victor Hess, ascended to 12,500 ft (4000 ft above ground level at the launch site near Snowmass Village). Grad student Heather Zorn (University of Washington, Seattle) carried a 2-channel portable Geiger counter to make accurate measurements of radiation levels as a function of altitude. Her readings were relayed by 2-way radio to Greg Snow (University of Nebraska, Lincoln) who plotted the data and gave a blow-by-blow description of the experiment to the waiting public, represented by about 20 early-rising citizens. Hans Berns (UW, Seattle) provided technical expertise on the ground, and Fred Gorrall skillfully piloted the Unicorn Balloon Company's 240,000 cubic-foot hot-air balloon. The intrepid flyers were accompanied by roving reporter Dave Gordon of the Snowmass Sun.

The balloon was launched at 6:00 am, from the parking lot of the Snowmass Rodeo Grounds. A series of 5-minute counts were taken, at 9000, 10,000, 11,000, 12,000 and 12,500 feet above sea level (the launch site's altitude was 7900 feet ASL). The balloon ascended almost without movement, remaining directly above the Rodeo Grounds until reaching the highest altitude level, when light winds carried it slowly southeast. At 7:00 am, the balloon was brought down about 1 mile below the launch site, in a meadow along Owl Creek Road. 

The photos below, skillfully taken by Hans Berns on an Agfa e-Photo 1600 digital camera, include some from a test flight conducted on Saturday, July 7, 2001. Here's Hans enjoying the test flight on Saturday, 7/7/01 (with Greg Snow at left).

Data and discussion of the significance of the flight will be posted here in a day or two.

The photos below are arranged to illustrate the sequence of balloon flight operations, and include some photos taken during earlier flights:

1. Starting to fill the balloon with hot air (thanks to Beth Beiersdorf, Notre Dame University, who took this photo during a separate balloon flight on Friday, July 7).
2. Balloon inflated, preparing for launch: Wilkes (garbed as Hess - many thanks to Josie Gardner and the U. of Washington Drama School Costume shop!) gets instructions from pilot Fred Gorralls.
3. Wilkes takes a (simulated) reading on a beautiful replica of the Wulf Wire Electroscope used by Victor Hess, built by Larry Stark (UW Physics Instrument Shop ) from original drawings published by Theodore Wulf in 1911.
4. Just before launch: Heather Zorn and Jeff Wilkes (in basket) with Greg Snow (back to camera), talking to the enthusiastic audience watching preparations.
5. Launch! Up, up and...
6. Away!!
7a. Propane burner used to supply lift: passive and
7b. Propane burner active!
8. Telephoto view of balloon hovering 1000 feet above launch site, taking counts.
9. Greg Snow records the first data points relayed by Heather from the balloon.
10. View of Snowmass Village from 3000 feet relative altitude.
11. Anxious crowd watches the plot build as balloon ascends...
12. ...Good data being acquired... (Chris Quigg is highly visible in red shorts).
13. Telephoto view of balloon hovering at highest point (4000 feet above launch site), taking last set of counts.
14. Descending along Owl Creek Road toward landing...
15. Greg Snow happily explaining data to the crowd at the launch site. Red data points are from a test flight the previous day.
16. Approaching landing site...
17. Safely down! (This photo is from the test flight on Saturday, 7/7). Greg Snow (foreground) and Jeff Wilkes (background) helping secure the balloon.

Following are photos from the "Conversations with Scientists" session conducted by Greg Snow and Jeff Wilkes at Snowmass Village Mall on Saturday, July 7, 2001:

1. Greg Snow as 21st Century Scientist and Jeff Wilkes as 1911 Scientist, warming up the crowd.
2. Describing and explaining the Wulf electroscope.
3. Questions from the audience...
4. Explaining the dual Geiger counter used to take balloon flight data.
5. Final questions and closing out the session.

Note: This website will be enhanced with more photos, descriptions, and explanations - visit again!!