Perlan II Project Aims To Fly a Glider To the Edge of Space

Zothecula writes: In an ambitious attempt to break every wing-borne sustained flight height record for a manned aircraft, the Perlan ll project intends to construct and fly a glider higher than any sailplane has gone before. Riding on the colossal stratospheric air waves generated over mountains, the team plans to fly their craft to more than 90,000 ft (27,000 m), which will shatter their own existing glider altitude record of 50,671 ft (15,400 m) set by Perlan l in 2008.

Comments

100km

[Anonymous Coward]

At 27km up, you're closer to ground than to the edge of space. Stop sensationalizing.

Re: 100km

[calidoscope]

Something on the order of 97% of the atmosphere's mass is below 90,000'. 100km is an arbitrary value for the start of space, as the air at 100km is too thick to orbit and too thin to fly in (except dynamic soaring?). In imperial units, 100,000' seems to be the upper limit for flying and 100 miles is about the lower limit for orbiting.

The Perlan II sounds like it will handle like an unpowered U2 - where the planes ceiling will be defined by the "coffin corner" were the low speed stall (classic stall) approaches the high speed stall (Mach tuck from transonic airflow). Perhaps they will be using a more refined airfoil than the U2 to increase the Mach number for high speed stall.

IIRC, the pre-Perlan I sailplane altitude record of approx 47,000 feet was set sometime in the 1960's, surprising it took that long for someone to break that.