Wave Rider | Perlan 2 Sailplane Soars to the Stratosphere

[@scottmanley]

Excited to see this push the limits!

[@noelwade]

Jim Payne, the lead pilot, gave a great presentation about Perlan (and some other incredible flight-test projects) at our Soaring Society of America convention last week in Reno. You would've loved the details he was giving about how the systems work, how the wave transitions from the Troposphere to the Stratosphere, the logistics of even pulling this off, and the Perlan envelope at these altitudes. For example, their "coffin corner" (where Vne and stall speed converge) is somewhere around 96,000'. At their target of 90k MSL they have about a 10 knot envelope, with IAS around 55 knots translating into a True Airspeed of ~350 knots! [For reference, most modern sailplanes have a Vne of around 160 knots TAS] As someone who's set a few modest sailplane records (and who got married with the Perlan 1 hanging from the ceiling above me), the stuff they're doing is damned impressive!

[@Allan_aka_RocKITEman]

*_"FLY SAFE!"_* 😉

[@jonslg240]

Me too, I believe I first heard you mention it, Mr. Manley =p I didn't know how far along it was until seeing this video.. Supposedly a glider like this can theoretically stay up for weeks at a time, is that true? (Not this exact one, just theory)

[@alleycatsphinx]

This is like dejavu of the time I learned the fastest RC planes are unpowered (via dynamic soaring.)

[@jonathanm9436]

@@noelwade Thanks for contributing - very interesting.

[@geoffery777]

I've followed The Perlan Project for about 7 years now. It is, hands down, my single favorite thing happening in aviation at this point in time. It's truly a remarkable aircraft and an absolutely incredible group of individuals making things happen, on the ground and in the air.

[@iplanes1]

I have been teaching science for 40 years and I long ago realised that the most important ability that a science teacher can have is boundless enthusiasm for science. It is this that inspires students even if and sometimes because the teachers ideas a wrong. The enthusiasm to find out how everything works is what is important. These guys had and are enthusiastic teachers.

[@TheYxxy]

Would it be at all possible to have more flight footage, maybe even inside the cabin, to show the remarkable lack of noises during the flight? I think that would be really amazing!

[@babboon5764]

I suspect it will be quieter as a combination of : Superbly efficient design making for exceptionally good airflow around the sailplane + Thinner air means less 'grip' or resistance? But footage from inside the cabin whilst interesting perhaps won't mean much on that count so much as the setting on the microphone. Its a nice idea 'though.

[@nidgem7171]

@@babboon5764 And therefore less turbulence which is what makes the noise (As implied with the good airflow point)

[@Chris_at_Home]

What made me find this video was one I watched that just showed about three minutes from inside at 66,000 feet. It was quiet and you could see all the flat screen displays.

[@johannesgaida3137]

Just knowing how quiet a regular glider is in wave, I can't image how quiet this must be!

[@TheYxxy]

@@Chris_at_Home I found that after I wrote the comment too. The Perlan Project channel seems generally really cool and in-depth!

[@lecutter9382]

Beautiful. What a glider! All sweetness and light. If you've never been gliding before I can't recommend it enough. I'm not a pilot but I've been up a dozen or so times and it's the closest mankind can ever get to being a bird. Probably the best money you'll ever spend on anything if you love flying. And to see these people doing this simply for the love of it. Amazing. Humanity can be such a dark dismal species, but once in a while we really doing something good.

[@twiggy27111976]

Things like this are why we progress. Well done to all involved.

[@jimdennis2451]

All we see in the news is how we are regressing as a whole. This is definitely a breath of fresh air... sorry for the pun.

[@EngiRedbeard]

Wow, being on tow for an hour and half. That is some stick and rudder endurance. Seems like the glider doesn't have very good forward visibility as well so staying on tow would be even more of a challenge.

[@jimmygadd]

towed for 6 min in thermals is hard enough and make you sweat

[@OrangeDurito]

Mr. Warnock’s enthusiasm about his project is almost palpable. What a fascinating project! All the best to everyone involved. Excited to see it pushing boundaries.

[@orangelion03]

I am in true awe of their accomplishment. Magnificent.

[@AlexanderStraub1]

I love this mission, Ulf Mehrbold a German Astronaut told me once in Berlin how exciting it is use gliders to fly Andes long distance flight paths

[@efoxxok7478]

We were privileged to own a previous world record holder from the early 1970’s to the mid 80’s. From Wikipedia “A single 1-23E model was constructed for Paul MacCready to compete in the 1954 World Gliding Championships held in Great Hucklow, United Kingdom. He flew the "E" to a fourth place finish. The aircraft was originally constructed without a wheel and used a skid for takeoff and landing. After the Worlds a wheel was retrofitted.[2][3] The aircraft was subsequently sold to Paul Bikle and he used it to set two world altitude records on 25 February 1961.[1] In the mid-1980s it was owned by the Rochester Soaring Club.[2] The 1-23E was not certified.[4]” The maximum altitude was lower than t(e starting altitude for this current generation I would note. Due to ailing health from my father we sold it to the mentioned glider club the new owners traveled NY to San Diego to buy it from us. Last I heard the Bikle family had repurchased it, restored it to 1961 condition and put it in a museum in Chino Ca.

[@jeffreycalder8185]

Paul was pretty cool. Project admin at Edwards AFB. I remember meeting him when I was a teenager. I met Paul MacCready when I was 5-6. My uncle did a great deal of the drafting work for Paul on the Gossamer Condor.

[@William_Bryant]

This is the truest form of flight.

[@Reynard_11]

I disagree. And I know many avians & insects that will back me up!

[@randomguyinanglider4090]

@@Reynard_11 well turn your engine on and put it in full throtle until you run out of fuel while we fly further ,higher and faster 😜

[@senatorjosephmccarthy2720]

The real purest flying is standing on the skid of a Loach 5/8 mile high.

[@Aengus42]

Beautiful! She looks like she belongs up there! Such elegant wings!

[@NiCadHeliPilot]

KZbin Reccommendations are on point, this morning.

[@NetVoyagerOne]

I'm just as interested in the Egret!

[@sheerluckholmes5468]

Google Grob G 520 it's a very interesting aircraft

[@LeWi100]

The Egrett is an absolute beast of a turboprop

[@benjamin.DWG1]

This plane is absolutely gorgeous

[@gregqualtieri609]

I used to fly sailplanes in the 1970 in southern CA. WE were limited to 15000. no O2 on board. Great pilots and sailplane give credit where credited is due.

[@scottkleyla7752]

Give us a lift mate?

[@scotthealey1887]

Holy shit! More footage of high altitude soaring would have been good.

[@senatorjosephmccarthy2720]

Holy What?

[@geoffery777]

There's a lot of awesome high altitude footage on The Perlan Project's KZbin channel, including a video of their world record flight to 76000ft.

[@ronprince1478]

Thank you people, it’s only the people that push the limits that advance mankind. It seems like it’s up to the private sector to do this,, and thankfully we do.

[@chrisoakey9841]

I would love to see a strut version of this sort of aircraft. The top sail wing projecting backward from the top of the fuselage, meeting a rear wing coming forward to meet at a winglet. This allows huge wings to start in tension. And you could have electric impellers powered by solar to propel yourself all that way.

[@vitale6633]

Awesome. Glider technology and application continues to evolve in amazing ways.

[@ronkirk5099]

There is nothing like soaring flight. Back in the day, I took a couple hours of dual in a sailplane after I got my private pilot's license and was hooked on un-powered flight. Later I started hang gliding and that was the ultimate for me. The second and third generation gliders really made high altitude, long duration flights possible.

[@scottkleyla7752]

A dream to fly for sure,go NAVY

[@loginvidea]

What a project. Wish You guys good weather and lot of air time. For science!

[@DaveBuildsThings]

This is new to me! Never thought a glider could get that high into the atmosphere to see the curvature of the earth. I am truly amazed! Congratulations and great work to all involved. 👍

[@hugonora2083]

Beautiful airplane! Amazing project! Congratulations to the team!!!

[@lrowlands53]

"... there's nothing that I could do that would be more exciting, more interesting than this." A spectacular statement.

[@KyleCowden]

About the closest to soaring like a bird in aviation... a space bird.

[@johnl5525]

Steve's soul is down there with you guys at SAWC. Fly high!

[@HandFromCoffin]

1. I have no idea a glider could get that high 2. I had no idea any prop civilian looking plane could go to 55k

[@HandFromCoffin]

I retract #2 after watching more and seeing it's wings. It's not just a normal looking civilian plane.

[@oldtimer2192]

It’s a turboprop aircraft, very powerful.

[@MatthijsvanDuin]

@@HandFromCoffin Hehe yeah, it's not your average single-engine turboprop..... "It was intended to fill a joint German Air Force - US Air Force requirement for a high-altitude, long-duration surveillance platform" [..] "the program initially attempted to acquire the Lockheed TR-1 (U-2) for this role, but when this did not succeed, a new aircraft was sought"

[@LCdrDerrick]

This or the Singer DLS? Well, the Singer, but as a former hobby glider, I am amazed! Mankind is not only mad! There are a few sparks of dignity and beauty here and there.

[@old_guard2431]

Old men pushing the limits. This old man sitting in a recliner applauds you.

[@juanlapuente833]

Congratulations, vamos Argentina!

[@CascadiaAviation]

The Egret tow plane is an absolute beast, what the hell? 47,000 foot tow??

[@LeWi100]

I also didn't know the Egrett is this powerful, and it is already 35 years old

[@robertlafnear7034]

COOL🤗👍👍👍 wish I could have seen it at Oshkosh.

[@thatsworrisome]

How majestic! Y’all must feel like an Angel flying upon the shoulder of God surveying His creations silently with more than a wing and a prayer. Godspeed! 💫

[@michaeldow2955]

That is remarkable

[@yikes1]

It was amazing to see this at oshkosh!

[@kennethperian4370]

Great job showing and telling, things about gliding up 100.000 feed. I live a few miles from a glider airport,but did not know you can go that high. Thanks for showing telling and well hope to see ya next time see ya bye.

[@teeanahera8949]

Mate, use a comma, not a decimal point for distances, example 100,000 feet. You also put “feed”.

[@kennethperian4370]

@@teeanahera8949 okay T I no good at thinking while spelling,bad at it . Thanks for letting me know , have a good one well see ya next time see ya bye.

[@svennoren9047]

@@teeanahera8949 Both points and commas are accepted as decimal separators by the International Standards Organization. Points are mostly used in english speaking countries and commas by most of the rest. Those who use decimal points use commas as thousands separators, and vice versa. ISO recommends using a no-break space as thousands separator. Like so: 1 234,5 or 1 234.5

[@stejer211]

@@teeanahera8949 Also, distances in football fields and weights in city buses. Because 'murica.

[@lohikarhu734]

welllll....superb! beautiful aircraft, both...the 'Egret' is a "pretty strange bird", no? kind of a turboprop U2? Did it have a specific mission, other than this?

[@atomicsmith]

Beautiful. Really looks like Burt rutan was a big inspiration to the team.

[@scottcates]

This is the best in aerodynamics.

[@Sm00k]

Going to space on wings of silence, instead of roar of rockets. Now. That's cool.

[@simonhogan2379]

If you happen to see Balleka while you’re up there, give him a wave and a nod from us.

[@billindurham]

Amazing in all aspects! I’m curious about where they have been operating out of in SA and where they have been catching the highest wave conditions. Can anyone comment? (Former sailplane racer and frequent visitor to Patagonia here)

[@sanfranciscobay]

Did they say Argentina?

[@noelwade]

They fly out of El Calafate, Argentina. Their next attempts will be in August & Sept of this year.

[@babboon5764]

I MAY be wrong (I do it so well, having had practice) but I think the wave is mostly ridden around Northern Chile & mostly Peru. Not sure where they launch from 'though.

[@kirkglundal4289]

Excellent! Wait a minute... you mean you don't want a tow to 3000’ AGL with that beauty? LOL

[@richard0crewe]

It's peculiar that it has a fixed undercarriage when it's common for modern sailplanes to have a retractable wheel. Guessing it's something to do with pressurisation and bulkhead position (or lack of bulkheads.)

[@jagtan13]

Was thinking that to but, low speed high altitude flight requires lightness to be paramount. If they're flying around 80 knots the retract would just add weight and complexity, decreasing altitude.

[@1967250s]

Probably very little extra drag at those altitudes where the air is so thin.

[@timoadler6356]

@@1967250s well, the low density has the same impact on lift then it has on drag. In order to compensate for that they need to fly faster at altitude, resulting in an identical lift to drag ratio no matter if they fly low or high. The drag penalty of the undercarriage isn't mitigated by the altitude. If I were asked to design it, I'd have the gear fixed as well just because it can't freeze and fail to extract or be forgotten plus it's a lighter design when fixed.

[@vertigo2893]

pressurization, maybe, but I guess its more about saving weight. A retractable undercarriage is heavy, and they are flying right up to "coffin corner" where never-exceed /flutter speed and stall speed come together. Reduced weight means lower stall speed, which is probably more important than a little less drag (especially at those low indicated airspeeds). For regular gliders, its the opposite, we usually carry extra water ballast, as that gives us higher cross country speeds. We just dump it before landing to regain lower stall speeds.

[@Felix-bj9et]

I was wondering the same. If it was about the weight only, I would wonder if it wouldn't be lighter then to make the cabin not pressurized (and add pressure suits instead). But I guess they thought it all through ;) My guess would be that there is maybe simply not enough space since it's a duo glider (look at the position of the rear windows vs the position of the main landing gear). I imagine that as the main gear has to be somewhat close to the position of the COG, it might be simply not possible to put it further back where there might be enough space (?). Maybe they could make a retractable gear that swings back as it retracts but that again adds weight. Seeing the size of the gear and its fairings compared to the body though, I would think that it might make a noticable difference. But maybe that's just something yet to be developed for a later version. After all, they gotta start somewhere and if they wanted to make everything perfect by version 1, they probably wouldn't be flying at all.

[@wesleycardinal8869]

That shot at the end of the video!

[@ronkiser5236]

Been following since the beginning ☑️

[@gerryhouska2859]

Pure magic! Wish they would take me as a passenger...

[@dr.gudmundssonaircraftdesign]

Fascinating and inspirational!

[@yzScott]

Egret = Porter and a Grob 103 had a baby. Pretty cool.

[@LostCylon]

One of the comments at the last was interesting, testing to see if wings could work on Mars. The air pressure on Earth at 90,000 feet is 0.255lb per square inch. On Mars at ground level it is 0.095 psi, however Martian gravity is only about 38% of Earth. That's kind of close to doable, and the recent mini helicopter drone, although limited due to recharging capabilities, worked well. With the greatly lessened air pressure, a sail plane needn't be made to survive high gusts and stresses, it's possible that a similar sized robotic blow up one would work fine, and only be 1/20th the weight. *WOW*

[@stuartvorster4911]

What a beautiful Bird...

[@christopherbrett]

Wow! Can Iraise my hand as a volunteer. I live in Australia….but anything I can assist in…I’ll endeavour to do it! This is so exciting….

[@RizHassan]

How do you track and follow these waves while flying the air plane? How long can u sustain 70k ft altitude? Amazing!

[@tkorte101]

This is awesome!

[@chrissky2639]

Put Sebastian Kawa in that glider. The first man to fly a glider over the Himalayas

[@st3v3nk3]

If i would have the knowledge, and i would be capable of these thing i would never retire..

[@RobouVideos]

so when you tow a sailplane very high, it can sail very high!

[@bvnj123]

80 IAS is almost 200 TAS at 70K. Would be interesting to test the electric propulsion at that altitude. For a possibility of long distance travel.

[@TrevorDennis100]

He already had my full attention, and I could absolutely feel his excitement, but when he mentioned wanting to 'test if wings were any good on the planet Mars', well that just about blew my mind. I am not sure how seriously we can take that as the glider apparently likes to fly below 80 knots, and I have a feeling wind speeds on Mars can greatly exede that, but the data this project generates can only be helpful.

[@edmoore]

I believe 80kts refers to the indicated air speed, the true airspeed over the ground being much higher because of the much lower air density when they’re flying. It’s a slightly confusing aviation convention to call it ‘indicated airspeed’ when it is really ‘dynamic pressure’ - the pressure caused by your body accelerating molecules of fluid as you move through it - but for a given IAS or dynamic pressure, the velocity must increase as the density decreases. All of which is to say that 80kts IAS on mars would be pretty speedy as a ground speed!

[@WhiksyKilo]

@Trevor - Mars atmosphere, though predominately CO2, has very similar characteristics to that of Earth. The sun's energy heat's the surface warming the closest layer generating rising columns of warm air which climb through the lower atmosphere in an exact analogy of thermals used by soaring sailplanes on earth. Doppler radar confirm the presen of both verttcal & horizontal air mass movement (wind & thermal) sufficiently strong to offer soaring flight given Mars surface gravity is around 0.4G.The sailplanes would look a little different (wing area/loading & aspect ratio) but soaring is one sport that could be shared between both planets.

[@MrSimonw58]

Wave rider towed to the stratosphere

[@christopherlent7895]

I'm impressed.

[@bagoistvan3182]

....no wonder that AIRBUS is taking an interest in this project.... I bet fifty bucks that somewhere in an obscure design office their engineers are busey collecting and analyzing telemetry data from this flights ....and perhaps thinking about the airliners of the future. Some sort combination between a high performance glider and a jet liner able to utilize the dinamic energies of the atmosphere to his advantage , soaring hundreds of miles at minimum fuel costs ....😏😏😏

[@GoldenEDM_2018]

That's how competitions in capitalism work, you fund research and design to create better products than what your competitor could offer.

[@bagoistvan3182]

@@GoldenEDM_2018 yeahh.. Capitalism - a love story. I saw that movie too...😁😁😁

[@KidsBooksClub]

AWESOME! Is the a/c trackable in flightradar?

[@OLDMANTEA]

Incredible

[@LuciFeric137]

Looks like a Scaled Composites design.

[@scottkleyla7752]

Safety first,go NAVY

[@therealgaragegirls]

Very cool!

[@KidsBooksClub]

Why stop at 90k feet? Is the air too thin to support flight any higher? Or is the stall speed/flight envelop to narrow etc.?

[@KidsBooksClub]

Found it in the comment below "(where Vne and stall speed converge) is somewhere around 96,000'. At their target of 90k MSL they have about a 10 knot envelope, with IAS around 55 knots translating into a True Airspeed of ~350 knots!"

[@russbentley7677]

Easily as beautiful as the finest sailboat. Able to sail in three dimensions. and into the fourth in its ability to remain aloft indefinitely.

[@brucepickess8097]

"Remain aloft indefinately" ?, not with flat batteries, and depleted oxygen supplies etc.🤔

[@pauljs75]

Dynamic soaring on the edge of the jet stream would offer near unlimited endurance, but that's a different set of challenges. For one, the best conditions don't specifically rely on uplift from mountains so you'd have to have some means of analyzing where that constantly shifting and flowing boundary is. You could just loop around the planet wherever it goes for a given hemisphere. It's documented as possible, and there's been a few studies that have considered it. But I haven't heard much about anyone trying it yet or significantly doing anything in that regard.

[@thewayfaringanarchists8157]

Sick!

[@royksk]

Quite amazing

[@theoldman8877]

I am curious about the landing gear configuration. Most high-performance gliders use retractable gear. This appears to be fixed gear in a pod, which adds a great deal of drag to an otherwise extremely slippery aircraft. Was the landing gear configuration determined by the need to make it a pressurized fuselage ? Or was it a need for more space inside the cockpit for LOX bottles & and equipment ?

[@budyeddi5814]

Here for the answer

[@jimmygadd]

I'm no scientist, but the cold might have an impact here, if it's too cold something can freeze, but after a record flight a belly landing is the least you have to worry about

[@glike2]

Cool project, but John Powell's supersonic balloon to orbit is much more interesting

[@Fubarpapa]

Amazing

[@lord_scrubington]

this is very epic

[@queeny5613]

Awesome

[@RANDOM24h]

The wheel does not look very aerodynamic? Is there so much energy?

[@thomasmackey6760]

This has the look of a Rutan aircraft. Did he have any involvement in terms of concept or engineering?

[@tomellis487]

Convergent evolution.

[@stejer211]

Round windows have been used for ages because they distribute air or water pressure more evenly, with less chance of material failure. If Burt Rutan was involved this glider probably had wings of unequal length, or at least it was a canard ;)

[@vertigo2893]

@@stejer211 and he would have tossed a scale model from a tall building to eye ball its flight characteristics. i think Im happy Rutan wasnt involved :)

[@gordonyork6638]

Wasn't this built in Bend Oregon by Windward Performance?

[@transistor754]

Is there any danger that the plane would go divergent at that altitude I.e. 100 000 feet and above? Why did some high flying aircraft need reaction thrusters? Awesome! Thanks.

[@vertigo2893]

No. Compare the wings of that Perlan with those of an X-15, and spot the difference. The X-15 flew at 200-300K feet, it basically flew a rocket powered ballistic trajectory in to space, aerodynamic control surfaces on those tiny wings would have almost no effect at those altitudes. The Perlan can only fly as high as its wings provide enough lift, that means you can have enough differential to provide control authority. The real danger is flutter and stall speed converging, to the point where Vne and stall speed become the same.

[@MisterIvyMike]

Not the sort of plane and flight I want to fly! Why? After maybe 45 minutes I have to pee, than my feets get cold and after that my back hurts... 😆 But I admire people who are able to do that! So the only thing that makes me a little envious is the fact that I will never see the curvature of the earth with my own eyes. 😔

[@mikebengyak199]

I have been awaiting things like this for 65 years. Just like going over the Niagara Falls in a barrel - Time for MARS, just sayin. President Kennedy said " Lets Go " kinda

[@footsy420]

keep climbing! My heart is with this project not that its going to help.

[@hadleymanmusic]

Look maaa top of the earth

[@repalmore]

Cool.

[@ConradSpoke]

The things that men do, just because they feel like it, never cease to amaze me. This is where civilization happens: a machine of men.

[@kevinflick61]

I just want one ride 👍

[@Allan_aka_RocKITEman]

*WOW!*

[@Karl-cg9cv]

This could become a cost effective and efficient way to space

[@AquarianNomadic]

No it can't.

[@MatthijsvanDuin]

It can't carry any significant amount of payload, but far more importantly it can't even remotely get enough speed. The hard part of getting stuff "into space" without falling right back down (i.e. into orbit) is accelerating to orbital velocity, around 34000 km/h (21000 mph / 15000 knots / mach 23 (*)) for low earth orbit. Only a small portion of a rocket's fuel is spent on going up, most of it is for accelerating horizontally. The main reason for going up is to clear (most of) the atmosphere, which is needed because if you'd attempt to accelerate to orbital velocity inside the atmosphere you'd burn up. (* mach number assuming speed of sound at normal atmospheric conditions, not really meaningful for a spacecraft except as a way to phrase such high speeds that's perhaps easier to grasp than just some big number.)

[@unguidedone]

wow and i thought those altitudes were limited to the u-2 and sr-71

[@bowser515]

And the English Electric Lightning a hair off.... But straight up.

[@brucepickess8097]

​@@bowser515 I believe the Lightning maxed out around 50kfeet, however some say greater than 60K feet.

[@bowser515]

@@brucepickess8097 That was its more standard service ceiling for sure, but it was recorded going much higher. There's a fun old story about a lightning upsetting the usaf during an exercise in 1984. I'll let you look it up as it's a good read. But the jist of it was that a U2 sitting "safely" at 80k plus had a little surprise that day.

[@diraziz396]

Biggest waves on the Planet.

[@robwilde855]

What puzzles me is why the design included that fixed wheel.

[@thearmouredpenguin7148]

My guess would be that the added complexity of a retractable main wheel, _that was fully pressure sealed,_ would lead to a weight penalty that would outweigh any gain in performance, especially bearing in mind that this was probably not designed for max L/D at high speed..

[@hattrick2219]

No pressure suit.....tickling the tail of the dragon.

[@npsit1]

Flerfs: FaKe NeWs! But seriously, nice aircraft.

[@JESUSCHRYSLER5512]

BLEFERFUL SCHURFUL

[@sidb9540]

so this thing went to where only the U2 spy plane goes... and that too without an engine?? :O

[@alistairclark6814]

Has this glider been able to climb up from lower altitudes independently using lift, or has it only been towed up to altitude? And can it maintain altitude when released up there?

[@ulrichkalber9039]

it can raise up there, towed to 47000 is the record tow, the record flight was 76000, that means they had to raise 29000 feet or more after release.

[@MatthijsvanDuin]

My understanding is that the main reason to tow it up to the start of the stratosphere is because the right stratospheric conditions are pretty rare so you don't want to take any chances on the tropospheric part of the climb.

[@ulrichkalber9039]

@@MatthijsvanDuin interesting. could it be that the time taken to climb might see an end to the ideal conditions before the attempt would be over? i.o.W: could it be that the time with ideal conditions is limited, and is needed for the climb from tow height to record height?

[@MatthijsvanDuin]

@@ulrichkalber9039 I think more that the conditions in the troposphere may just not be great for gliding, but I'm not sure. Plus the time it would take no doubt. The stratospheric climb is the part they're interested in, so it makes sense to just "skip" the troposphere by towing through it.

[@WhiksyKilo]

The answer to your questions are yes and yes. Perlan is specifically designed to be efficient at very high altitude, it's efficiency is therefore not comparable with conventional sailplanes at lower altidues. Conventional sailplanes have reached 50kft+, pilots cannot survive above that height without a pressure suit or cabin. The transition from tropospheric to stratospheric wave requires very rare atmospheric conditions, it has been done by Perlan but just a handfull of times and never reliably. The purpose of Perlan is to explore flight in the stratosphere, it makes sense to short cut the transition. Once established in stratospheric wave, Perlan could stay there forever, dependant only upon the continued existence of the wave system and the onboard life support systems (e.g. Oxygen).

[@petergreis]

Would love to ride back seat in this….

[@jmpcrx]

Need a big winch to get that high