Return To Home from the Stratosphere

(Thumbnail by Darrin Vanselow for PME)
Regulations: The system is considered as a normal radiosonde/weather balloon in Switzerland and in the US already. Thus the same rules as for normal radiosondes applies. In Switzerland, no special permission is required to launch a balloon with a payload of less than 2kg, and a volume of less than 30m^3, from more than 5km away from any airport or restricted area. A special insurance is required for payloads of more than 500g. More than 800'000 radiosonde of similar weight and size are launched every year all around the world.
What is it? This is a 240g glider returning to home after releasing from a weather balloon at 30'000m altitude. The ascent time is 100min and the descent time between 35 and 45min depending on the day. The landing accuracy is roughly 30m. The glider is completely autonomous.
Project update: after 5 years of work. The technical challenge is solved. The reusable radiosonde is ready. After exploring guided parachutes for 4 years it that appears the added complexity of the parachute deployment is a bit too high.
I integrated all the software and electronics developed for the guided parachute in an ultralight glider: small and light enough to fit in the same category as standard radiosondes, yet smart enough to come back to launch site on most days.
More infos about the next step soon here: r2ho.me

[@4rs30ax]

Daft Punk's tribute was a great choice.

[@PrivateCapitalTrading]

"My name is Giovanni giorgio, but everybody calls me Giorgio..."😉

[@DS-xg9kf]

Tune!!

[@Part_121]

Awesome! I can't believe you were able to find the field from that altitude. I have a hard time finding my field when I'm just looking at a map of my town! 🤣

[@YohanHadji]

oh, it's all autonomous! I didn't have to do anything during the flight!

[@sebastienc8797]

Impressive, you can see the roundness of the earth when the glider is at ~30km. (And it's not only the wide angle cam that makes it, you see it's more round when in altitude than when it's lower) Great work !!!

[@DrewWithington]

I'm still sure the Earth is flat. And I always will be.

[@sebastienc8797]

@@DrewWithington I don't doubt it.

[@Sajuuk]

​@@DrewWithingtonYour IQ bell curve is flat 😂

[@Clickmaster5k]

Ya that's how we know this is fake news because the real earth as we all know is flat.

[@rvsamsung77]

​@@DrewWithington . You are sooo right, and now its time for your medicine and sleep.

[@danmartinrc]

Amazing job! I admire your dedication to making this work. It's an impressive accomplishment.

[@Del350K4]

Well done, mate. The four years weren't wasted, by any means!

[@r0cketplumber]

Two observations: At high altitude the control loop gain was a bit high and the damping low, you may want to adjust the PID gains vs altitude. If it can sense AGL you could add a flare to reduce landing speed.

[@YohanHadji]

yes! very good observations for both. These are actually the two main point we'll be working on this summer. For PIDs the best would probably be to do a system identification as function of altitude and then start from there. To "sense" AGL, doing a good sensor fusion between GPS and baro and knowing the precise GPS ground altitude should be enough (I hope). Currently the final landing approach is not at all optimized.

[@r0cketplumber]

@@YohanHadji In thinner air with high true airspeed the natural aerodynamic damping is reduced, so perhaps just increasing the D term would be enough to calm the loop down. You might be able to use a sim like X-plane to tune the gains. I agree that sensor fusion is the zero mass solution for landing but I know from bitter experience (crushed vertebra in a skydiving landing mishap) that the altitude precision needed is well under a meter. Perhaps an ultrasound rangefinder at just a few grams would be worthwhile.

[@leifvejby8023]

@@YohanHadji It could be Dutch-roll too at that altitude - they outfitted the Perlan2 with a yaw damper for that reason. You could just increase the size of the vertical fin/rudder. (Double the area - it would increase the drag slightly, but would help everywhere else).

[@jimcoughlin9932]

Excellent!

[@iatranger]

Shame you used a fisheye lense

[@aldoskyz8]

Wow big success! I am amazed by your work

[@FixTechStuff]

Fascinating. This reminds me of the Balloon project I used to follow many years ago, but without the searching part.

[@Roadtripexcursion]

look theres a curve flat earthers 0 curved earth1

[@haraldhechler3557]

Great Work! I appreciate the "70s tech documentation"-vibe the music adds to the video.

[@dpkgray]

Also, what is the velocity after the release and the plane accelerated in the low atmospheric pressure? I assume the drag to mass ratio is low compared to ground level. How many minutes return to home, from what altitude?

[@YohanHadji]

About 90~100m/s forward speed right after release at 29km altitude

[@YohanHadji]

Between 35 and 45min to come back home depending on the day, from 30km altitude

[@UKPete]

Great video and what a fantastic achievement!👍

[@owennowakowski7558]

I can't believe you got Werner Herzog to narrate. Amazing.

[@YohanHadji]

That's giorgio moroder! Not Werner haha!

[@CatchAUAP]

This song is thumping. Nicely done

[@TheTruthHz]

Incredible work, congratulations 👍👏👏👏

[@dawntreader7079]

very, very impressive.

[@KlingbergWingMkII]

What, no aerobatics? I would have been looping all the way down. Still, way cool and a great low cost solution. A friend of mine made a flight like this back in the 90s for NASA. They used one of those huge aerostat balloons. Total costs were in the hundreds of thousands. This is better.

[@jonas2097]

Love this one ! , thx for sharing !

[@kkuenzel56]

That was just Amazing!!!

[@TheBananaJoint]

Nice, perfect music selection as well ⭐

[@studiostarholden7364]

No more parachutes!

[@charleslongley7862]

Wow this is the best video I've ever seen on KZbin.

[@meprisesduciel]

Excellent ! Bravo

[@keithviolette5870]

Very impressive!

[@BenjaminKelm]

Great choice of Music ;)

[@engleharddinglefester4285]

Congratulations, that is quite a feat.

[@huskermike8096]

Great work!

[@Project-Air]

Incredible!

[@SpacemanFPV1]

Yes please do something like this our fog plane tutorials and teach how to make an ataunomouse plane

[@TerminusVox]

Awesome!

[@juhaeske]

Great achievement! 🎉

[@jean-marcgruninger9019]

awesome work.

[@gilbondfac]

Magnifique travail, félicitations...j'avais ce projet en tête après mon lancement de mon projet Apollo strato..en 2019....tu es un génie 😉

[@Damian-Church-NZ]

Well done dude 👏

[@ZephodBeeblebrox]

Well done!

[@Allan_aka_RocKITEman]

Great video...👍

[@bytesabre]

I remember RCExplorer/David Windestål doing something along these lines back in the day, but was using analogue FPV which was damaged when releasing from the balloon so wasn’t able to successfully land. I thought with the strict rules that came into force since then that we’d not see another attempt let alone a successful one :)

[@YohanHadji]

David has been an inspiration for a long time

[@bytesabre]

@@YohanHadji To us all. I still fly a V4 Tri, Old as hell, can’t get the configuration software to work any more, but still flies beautifully. I did get a LR kit before he stopped selling them, i really need to get around to building that up with a modern FC

[@keepyourairspeedup]

Pretty awesome!!

[@Hoopaball]

Amazing video! Let's see more!

[@RCFlyingDoc]

Ups... you crossed the International flight zone. did you get the aggreement of the flight Control Center. ? If Not It was a high risk for Airplanes and probably illegal. This is one of the reasons for ever stricter laws.

[@Hoopaball]

@@RCFlyingDoc 250 grams loser

[@YohanHadji]

This ultralight glider is considered as a standard radiosonde by aviation authorities at least in Switzerland and in the US. 800'000 radiosondes with similar weight and size are launched everywhere all around the world crossing air traffic all the time. This glider reduces the risk of an unguided radiosonde landing on an airport.

[@simontillson482]

@@YohanHadjiVery cool point, there. I know weather radiosondes are cheap(ish) but using gliders would make the electronics reusable for multiple flights. I don’t know the actual figures, but we must be sending dozens of those things up every single day. It does seem a waste. P.S. for anyone wondering if those weather radiosondes could fall on someone’s head or end up crashing into a car’s windscreen on the highway, yes they sure could! Luckily, they’re usually inside a block of styrofoam so don’t come down very quickly, and only weigh 100g or so, so not really dangerous.

[@cragbot1]

tarik in shambles rn

[@Adrian-jk4kx]

Fantastic

[@FormerlyKnownAsAndrew]

Incredible

[@chrismadge7292]

Nerdtastic ! 😊😊😊

[@feelincrispy7053]

Look at that beautiful CURVED horizon

[@dpkgray]

Great work. How did you determine that high altitude wind (jet stream) would make it difficult for a successful recovery?

[@amentma1778]

Amazing

[@slowvoltage]

🙏🏽 may i please have any of the following data from your work on this project? the average wind speed and temperature at 30km up, wing span, gps model, lipo or lion, 2s or 3s, amount of helium used for 240g to launch? 🙌🏽 wonderful project!

[@colzillafpv]

@scimandan here's a relatively low cost experiment :)

[@StabilisingGlobalTemperature]

I have a suggestion: if the glider could be attached with a suitable bridle (like the bridle of a kite) then it could steer on the ascent. So that on the descent it would not have such a distance to travel horizontally, for a given wind speed.

[@lllaszlo78]

amazing. (amazeballs)

[@johnnygustafson1243]

Zohd Drift, good choice, speedy bee F7 FC? Great shots!

[@StabilisingGlobalTemperature]

That is great. Question: what is the weight of the glider airframe, compared to the weight of the steerable parachute?

[@c.j.1089]

good music choice!

[@Commander-McBragg]

My eyes applaud you. My ears punch you in face.

[@nic_RC]

30km? And here I can't legally fly over 400'

[@sirferr3870]

You should name it C.H.E.M. (Chem-trail High Elevation Marker), great flight too!

[@Jivaromodelsvideo]

Fantastique ! 🤩👏💪

[@kotnapromke]

Нужно выше, выше! Чтобы как у Маска воздух раскалил фюзеляж!)

[@philippelambrechts6494]

YES !!! Super ❤💫

[@peppi0304]

thats pretty wild

[@untraceableghost637]

Is that the ZOHD dart?

[@jonathanstowe5852]

very cool

[@lekerbal52]

C'est génial !!!

[@sandhills2344]

So many chemtrails!

[@carstenaltvater]

Amazing! Hilarious!!

[@dgw4150]

I apologise, all i can hear watching this video is "i need your boots, your jacket and your motorcycle" 😂 Great video though.

[@JudahCrowe-ej9yl]

Nice

[@techtinkerin]

Yeah man wicked

[@bikeforever2016]

Sweet, good job Parachute drop next?

[@GarageBandSuperheros]

This is Super Cool. Congratulations on successful flight! I just came across your post on Twitter. I'll definitely be watching for more videos on this. What was total flight time? Take off to touchdown. Or start of descent to touchdown?

[@YohanHadji]

About 1h40 minute for ascent to 30'000m and between 30min to 50min for the descent depending on the wind profile of the day!

[@johnmcvay2627]

Lets goooo!

[@marktalley2550]

What was the maximum TAS at altitude? Amazing

[@YohanHadji]

At 30km altitude the groundspeed is between 80 and 100m/s

[@lucadipaolo7824]

Great

[@avus-kw2f213]

What is the theoretical maximum range ?

[@YohanHadji]

depends on the weather of the day, can be about 80km upwind and 150+km downwind

[@avus-kw2f213]

@@YohanHadji that’s rocket range

[@iloveaviation-burgerclub-a8145]

Well, I have to admit that putting a fc on a glider, dropping it from a baloon using RTH is as good as an idea as the song Giorgio from Random Access Memories of Daft Punk is. The footage is damn cool and the drums in this song blast.

[@iloveaviation-burgerclub-a8145]

You can really see how thin the atmosphere is up ther by these aileron oszilations with full deflection and the whobbling of the plane. I really am inspired. Lidl Glider go space? 😂 How is the law for dropping something that flies down spiraling to the home destination through all flight levels? And lifting this up by a baloon in your backyard?

[@YohanHadji]

haha this is a bit more complexe than just putting a FC and using RTH, standard RTH won't work, I have a custom board in the glider doing all the guidance. I just updated the description with infos about the regulation :)

[@oli_flies_quads]

Amazing. You started somewhere north of Lausanne and the balloon drifted all the way to Valais... And all the way back with a fragile ZOHD Drift :-) How long was the ascent, time and altitude wise?

[@dilbert0815]

Great project But somehow I seemed to have missed the technical flight data. Max height? Flight duration? just about any interesting data ...

[@YohanHadji]

Yeah this is mostly just a video I did to celebrate for myself. Release altitude was 30'000m and flight time 100min ascent 45min descent

[@kjm-ch7jc]

Do you have to give warnings to commercial and military aircraft on launch day.

[@YohanHadji]

The system is considered as a normal radiosonde/weather balloon in Switzerland and in the US already. Thus the same rules as for normal radiosondes applies. In Switzerland, no special permission is required to launch a balloon with a payload of less than 2kg, and a volume of less than 30m^3, from more than 5km away from any airport or restricted area. A special insurance is required for payloads of more than 500g. More than 800'000 radiosonde of similar weight and size are launched every year all around the world.

[@Mephistopholies]

WAY cool!

[@kiazzamassaequipe199]

Qual receptor usou e em qual rádio?

[@YohanHadji]

it's completely autonomous, no RC control in flight!

[@kemfic]

banger

[@AngeloXification]

This could be a music video

[@canyonrunner331]

This is so damn cool! Whats the max distance it could glide back to home?

[@YohanHadji]

It depends on a lot of factors but returns from 80km distance (distance at release from the balloon at 30km altitude) have already been achieved.

[@LowSetSun]

So cool, gets my brain thinking! How about sucking the helium/hydrogen from the balloon into an onboard canister and reeling the balloon back into the plane? And run the electronics on solar and capacitors. Then it wouldn't have any operating costs other than maintenance right?

[@BelaJuTe]

How far would the glider be able to glide? I assume at higher altitudes the distance to descent would be much lower do to the much lower air density

[@YohanHadji]

From 30km altitude, we can "shift" the initial drift point (where a normal radiosonde would have landed with a normal parachute) on about 150-180km in any direction. Ideally, against the wing. The glide ratio without considering the wind is actually the same (or almost the same) at all altitudes because lift and drag are modified the exact same way with density. Flying a glider at 30km altitude is extremely cool because you can fly super fast and go against the wind almost no matter the wind speed. The optimal glide forward speed at 30km altitude is about 100m/s (360km/h).

[@AerialWaviator]

Making best use of extreme density altitude for optimum aerodynamics. This definitely outside to operational flight envelope of a typical RC flight controller software should anyone be wondering. ;)

[@hannesaltenfelder4302]

This looks like it will soon be used in war...

[@fiatbandit]

How did you controlled it

[@YohanHadji]

it's completely autonomous, no control from the ground!

[@bokusimondesu]

At what altitude did it release and how long did the flight/glide take?

[@YohanHadji]

30'000m, about 45min descent time

[@bokusimondesu]

@@YohanHadji Wauw. That is high...well, more like far away. And, a speedy decent! Thank you for your answer! 👍

[@IanCthrwd]

Give it about 10 years time then to do a few orbits and land at the same spot.

[@mark6302]

holy crap

[@abrahamzuniga606]

How spherical our flat earth looks!

[@kchastain3]

I didn’t know you could connect a transmitter to a plane from that distance. Was the flight back to the ground controlled the whole way down?

[@YohanHadji]

It's all autonomous

[@cougarten]

Why are there so many skewed spiral traces in the final path? I expected it going straight to you and only when it reached the destination starting to spiral around you.

[@YohanHadji]

haha this is the secret sauce, sometime you don't want to spiral above the landing site! you want to spiral somewhere else to end up landing at the landing site

[@joedirtpig814]

Impressive. What is the theoretical distance this glider could fly from that altitude?

[@YohanHadji]

Without wind, on about 150~180km from 30km altitude. Going back against wind it already came back from 80km distance from the same altitude.

[@dre1z3hn]

everywhere chemtrails..😮

[@blooskyy7]

Telemetry would have been interesting to view

[@kyleeames8229]

Fun fact: a U2 spy plane has such a shallow glide slope that were one to suffer an engine failure over the UK, it could glide all the way to Florida and land safely… so suppose one were to build a glider whose wings were endowed with the largest aspect ratio structurally feasible, equip it with photovoltaics and a chonky battery as well as arduPilot. Could it say, fly a waypoint mission that brings tens of thousands of kilometers from where it was launched?

[@MISTERLeSkid]

Who cares about data / facts, right? The U2 has a glide ratio of 23:1 and a service ceiling 90000' (17 miles), giving it a best possible glide range of 380-390 miles, or around 9% of the 4200 miles from UK to Florida. You were pretty close lol.

[@AerialWaviator]

Such a powered fixed-wing drone has been flown with photovoltaics. Flight(s) lasting over 2 months in duration have been accomplished. It climbs and charges battery during day, which extends flight into overnight hours of darkness while slowly descending on reduced power. With both chemical and potential energy storage reduced, as sun raises, it repeats the cycle. To learn more look up "Zephyr solar-powered drone".

[@littlehills739]

guided drive with tungsten rod next time :)

[@laurentducerf5575]

Excellent ! Le réflecteur radar n'est pas obligatoire ?

[@YohanHadji]

Non, si je ne me trompe pas aucune radiosonde en suisse n'est lancée avec un réflecteur radar. Je ne crois pas que ce soit le cas aux USA non plus.

[@AerialWaviator]

I believe most 1940-60's style radars have been retired. Modern ATC (air traffic control) mostly relies on aircraft sending a data pack when they receive a radio ping. The data packet contain airspeed, altitude, and other aircraft performance data. For more detail, look up ADS-B (Automatic Dependent Surveillance-Broadcast). This is the same source of data flight tracking services use to acquire real-time position and status.

[@richspillman4191]

Do you think you might be able to work into one of your next videos the line "GET TO THE CHOPPAH, NOW!" or "Who is your daddy and what does he do?" It would be much appreciated.

[@YohanHadji]

lol, will try