> Getting a balloon to 90km altitude is straightforward No, it is not. The altitude record for a high-altitude balloon is 53 km, set in 2002. Most high-altitud

> Getting a balloon to 90km altitude is straightforward No, it is not. The altitude record for a high-altitude balloon is 53 km, set in 2002. Most high-altitude balloons are limited to 37 km or so. 90km is nearly at the Karman Line.