I would think that a project like this would be improved by an order of magnitude by eliminating the Stone-Age whitestickytapewithyarnattached first attempt.

If the technologically optimized Mk IV Yawstring had been utilized from the outset of the program, I have no doubt that the target altitude of 90k would have already been achieved. And the Perlan Project probably would not have found it necessary to tow to 42,000 feet behind the Grob Egrett.

In fact, they might not have needed a towplane at all! (Or even PILOTS!)

Such is the magic of the Mk IV Yawstring, but it is not OLC or IGC approved..

I am not affiliated with the manufacturer or distributor of the Mk IV Yawstring in any way, except for the fact that I sent them money, they sent me a Mk IV Yawstring and I will get around to installing it someday, providing I can wade through the 400 page installation and use manual, which is not available in electronic format and must be downloaded from a dump truck full of clay tablets with embossed cuneiform symbols. I am up to Tablet 18, and have hopes of getting through the disclaimers and warnings later this week..

Stay tuned for helpful hints.