Gliding in the Stratosphere

"ttyymmnn" (ttyymmnn) 08/30/2018 at 12:35 • Filed to: wingspan, Planelopnik

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(Perlan Project)

On August 26, the Perlan Project successfully flew a glider at 62,000 feet to set a new world altitude record. The pressurized glider is towed aloft by a specially modified !!!error: Indecipherable SUB-paragraph formatting!!! turboprop and then released at 42,000 feet. The glider then climbs higher still by using seasonal !!!error: Indecipherable SUB-paragraph formatting!!! from the Andes Mountains. Glider pilots know all about winds that are pushed aloft by the face of a mountain chain, but NASA discovered in the 1990s that these winds can extend all the way into the stratosphere at certain times of the year.

From the !!!error: Indecipherable SUB-paragraph formatting!!! :

The Perlan 2 will fly to 90,000 feet at the edge of space to explore the science of giant mountain waves that help create the ozone hole and change global climate models. This will require the engineering of a spacecraft with glider wings that can fly in less than 3% of normal air density and at temperatures of minus 70 degrees C, conditions approximating the surface of Mars. These missions will provide education and inspiration for young people seeking careers of exploration and adventure in engineering and science. (Perlan Project)

Project engineers predict that when the glider reaches 90,000 feet it will be traveling at 350 knots, or about 403 mph. To put that into some context, the highest the mighty SR-71 Blackbird has ever flown is 85,069 feet, albeit at a significantly higher speed.

But why a glider when we already have aircraft that can fly this high? Because aircraft engines produce heat, and that changes the atmospheric conditions immediately around the aircraft.

The project, sponsored by Airbus, is currently in Phase 2. Phase 3 will see the glider soaring as high as 100,000 feet and reaching transonic speeds which will require a new wing design. Research flights will then be conducted in the !!!error: Indecipherable SUB-paragraph formatting!!! to investigate !!!error: Indecipherable SUB-paragraph formatting!!! and other signs of climate change.

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For more stories about aviation, aviation history, aviators and airplane oddities, visit !!!error: Indecipherable SUB-paragraph formatting!!! .

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Duck Duck Grey Duck FTMFW! > ttyymmnn 08/30/2018 at 12:40

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This is so cool!!!

ttyymmnn > Duck Duck Grey Duck FTMFW! 08/30/2018 at 12:42

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It really is. We’re talking gliding higher than an A380, higher than the U-2. If they make 90k feet, they’ll break the record set by the SR-71. It’s crazy.

For Sweden > ttyymmnn 08/30/2018 at 13:49

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Cool, but please add some H2O2 thrusters or something for attitude control in low density.

TheRealBicycleBuck > ttyymmnn 08/30/2018 at 15:45

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Our ground school instructor shared a glider story the other day. A pilot failed to get pay attention to his sectional charts   and mistakenly flew over the Bush ranch which is restricted airspace . He was greeted by a couple of Blackhawks. They flanked him on either side and signaled for him to land. He wasn’t carrying a radio, so all communication was done via hand signals.

The pilot waggled his wings and turned to follow , then dumped his ballast in preparation for landing.

As you can imagine, the Blackhawk pilots didn’t take kindly to someone dumping unknown substances onto the ranch, so they dropped back and prepared to blow a glider out of the sky.

Fortunately, another military pilot in the area was also a glider pilot and he recognized what was happening by the radio chatter. That guy saved the glider pilot’s life that afternoon.

ttyymmnn > TheRealBicycleBuck 08/30/2018 at 16:08

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then dumped his ballast in preparation for landing.

I had no idea this was a thing. Yeah, best to pay attention to those pesky No Fly Zones.

TheRealBicycleBuck > ttyymmnn 08/30/2018 at 16:10

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It was a new thing for me, too. So, I looked into it. The ballast is there to increase the glide speed, making it easier to fly fast. Dumping the ballast reduces the overall weight, increasing the lift, and lets the glider fly slower - things you want when landing.

ttyymmnn > TheRealBicycleBuck 08/30/2018 at 16:17

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Or, just put a jet engine on your glider. Of course, that defeats the purpose, but it makes for a great air show demo .

TheRealBicycleBuck > ttyymmnn 08/30/2018 at 16:21

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That’s a retractable jet engine on that self-launching glider!

ttyymmnn > TheRealBicycleBuck 08/30/2018 at 16:50

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Yup. Not sure if this one was retractable or not. I saw this at the Temple air show back in 2013. A beautiful Demo. Very graceful, and pretty quiet in spite of the engine.

TheRealBicycleBuck > ttyymmnn 08/30/2018 at 17:01

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It’s fixed, not retractable.

https://www.desertaerospace.com/other-sailplane-jet-conversions

https://minijets.org/fr/100-150/pbs-tj100/super-salto-tj100/