Latest flight news - links to Blogspot site

Links to news about my recent Solar-Thermal Aerostatic Tetroon (STAT) flights:

• Mike Wendland's article in the Free Press about my solar tetroons
• ARRL article about a solar tetroon flight
  

Other links:

• Short web article about the SoP flight (in French)
• Don Piccard's XAP site
• Steve Griffin's Tetroon page

For further technical details about STATs, please email me.

[The content below is historical in nature and profiles one of my first successful solar Montgolfieres... This design is now obsolete.]

The "Spirit of Piccard" Solar Montgolfiere

FLIGHT UPDATE!

The "Spirit of Piccard" made a successful flight on 22 June 2003. Launch was at approximately 9:00 AM local time in Sterling Heights, Michigan, and the balloon and payload landed outside of Bellefontaine, Ohio, a few minutes after 5:00 PM that afternoon. From the post-flight data analysis we believe that the balloon ultimately reached a maximum altitude of approximately 49,000 feet.

Radio contact with the payload was lost about two hours into the flight, just south of metropolitan Detroit at an altitude of 26,000 feet. While a failure of the onboard LiSO2 battery was originally suspected, it was later determined that the terminal node controller was misconfigured (it was set to listen on the national APRS frequency, 144.39 Mhz, and was *not* set for full-duplex operation) and thus it refused to transmit once the channel reached saturation at altitude.

Pilot reports filed that day show that the balloon was spotted at 32,000 feet over southern Michigan around 11:10 AM and later, around 3:45 PM, at 24,500 feet about 20 miles south of Findlay, Ohio (thanks to Mark Conner for those reports). Finally, a few minutes before 5:00 PM, a little girl spotted the balloon and payload approaching her family's home in rural Ohio.

At first the family thought that it was a manned hot air balloon, but as it came closer they could see that it was something else. The girl's mother was particularly concerned when she heard the audio beacon (a simple piezo buzzer) on the outside of the payload box as it flew overhead -- but the fearless father nevertheless decided to chase the balloon until it landed in a field about 400 yards away. He retrieved the payload and called us that evening.

Initial inspection of the envelope revealed a number of large holes just above the equator of the balloon. While there were numerous tears from the recovery operation, these appeared to be due to melting. Later analysis of the data from the temperature logger (which flew inside of the envelope) showed a sudden drop in internal temperature about five hours into the flight. This apparently marks the time when the structural integrity of the envelope was compromised. Several theories exist about this incident and will be discussed in detail at a later time.

Below are pictures from the launch, as well as data charts and a map of the recorded track. Clicking on the pics will open them at full size. Additional pictures, files and detailed analysis are forthcoming. Note that all pictures on this page are presently loaded at full size -- only the display size has been reduced. This means that the page will be slower to initially load, but clicking on a thumbnail will very quickly open the full-size image.

Please feel free to use the email link at the bottom of this page if you have any questions or comments.

(Note: The date on the camera was wrong - the flight was on 22 June 03!)

Background

"Spirit of Piccard" is the name of both this 4300 cubic foot solar hot air balloon (or "Montgolfiere") and the first mission which will be flown using this class of experimental balloon (the "P-1" class). The name is in honour of Don Piccard, one of the founding-fathers of the modern sport of hot air ballooning and an integral part of the Academy's new "Ballooning for Education" programme. The solar balloon project in particular was inspired by the work of Jack Jones at JPL.

The balloon envelope itself is a "natural shape" design and is constructed entirely of 25 micron black polyethylene film. A crown line attachment point at the top of the envelope also contains a Tyvek reinforcement and the integral load ring is made from rigid vinyl tubing. Payloads are attached with twisted Dacron line.

All flights with this balloon will qualify as exempt under FAR-101 due to the lightweight, low-density payloads. The payload for the "Spirit of Piccard" mission will consist of an APRS tracker, Amateur Radio digipeater, temperature logger and downward-looking digital camera. This mission is primarily a proof-of-concept flight for the overall balloon system and will provide our students with an initial experience with moderate-size balloon technology.

Photographs

Cold inflation tests, 29-30 May 2003 (click for full-size images)... Note that the envelope was actually inside-out during these tests to allow for seam inspections.

Earlier solar Montgolfiere experiments by Mr. Rochte:

Robert Rochte
rrochte@gpacademy.org