Dave Voit, WB6TOU, a fellow CARS club member, is involved with ebarc and has sent us the following opportunity to contact a repeater on a near-space balloon.
Info on the launch:
Date: October 27thTime: Either 11:00 or noon
Radio: Wouxon KG-UV8D with input on 145.56 MHz (162.2 Hz tone) and an output on 445.525 MHz.  Last time it transmitted at 0.5 W.  A handheld should work fine.

The call sign will be W6MRR-11 (this was changed from KJ6DZB-11)
The altitude reached should be 100,000 feet or higher.  The line of sight range is 1.23*sqrt(altitude in feet), answer in miles.  At 100,000 feet the range is 389 miles.  At 50,000 feet the range is about 275 miles.

The balloon will be tracked on APRS.fi and will show the balloon icon.  The sponsoring group is East Bay Amateur Radio Club at http://ebarc.org/index.html.  The total flight time is likely to be 2:45 or so.  The beacon should appear when the balloon reaches a couple hundred feet.   The APRS  display will show altitude and you should be able to estimate when you can hit the repeater.
Since launch time is not certain, watch APRS.fi for the icon to expect to worky the repeater. If you are far away, do the math for line of sight.

Contact Dave for more info at: dvoit1944@gmail.com

Good luck to Dave, the balloon, and everyone involved. Should prove fun and or challenging. 73. Mark, n6iv