Science |
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Znanost |
How high can a glider fly?
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Koliko visoko može letjeti jedrilica?
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Pushing back the limits of aeronautical exploration
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Pomicanje granica zrakoplovnih istraživanja
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World's tallest waves
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Najviši valovi na svijetu
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The first attempt
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Prvi pokušaj
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To the edge of space
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Put do ruba svemira
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Perlan 2
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Perlan 2
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A unique wing design
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Jedinstveni dizajn krila
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Atmospheric waves
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Atmosferski valovi
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How high can a glider fly?
Inside the glider high above the snow-capped Andes of Patagonia, air started to leak from a canister.
Einar Enevoldson immediately knew he faced a tough decision.
He was attempting to fly a glider to a record-breaking altitude of 15,000 metres and beyond - a feat that most pilots considered impossible.
With him in the plane was billionaire Steve Fossett, who was bankrolling the attempt.
High-pressure air from the canister surged through soft pipes and into Fossett's orange space suit.
It ballooned and stiffened.
This wasn't supposed to happen at their altitude.
If the suit inflated further, Fossett would be immobilised for hours...
Inside the glider high above the snow-capped Andes of Patagonia, air started to leak from a canister.
Einar Enevoldson immediately knew he faced a tough decision.
He was attempting to fly a glider to a record-breaking altitude of 15,000 metres and beyond - a feat that most pilots considered impossible.
With him in the plane was billionaire Steve Fossett, who was bankrolling the attempt.
High-pressure air from the canister surged through soft pipes and into Fossett's orange space suit.
It ballooned and stiffened.
This wasn't supposed to happen at their altitude.
If the suit inflated further, Fossett would be immobilised for hours.
Worse, his suit could block the controls, making it impossible to land the aircraft safely.
And yet, with the southern winter drawing to a close, this could be their last chance to fly.
Enevoldson, who was 74 years old at the time, had spent 15 years working towards this flight, and decades dreaming of it.
If they could only get high enough, it would prove his theory that a glider could ride high into the stratosphere.
Turning back would mean a huge disappointment, but carrying on was risky.
That was 2006.
This flight was part of a bold plan called the "Perlan Project".
Enevoldson reckons he has found a way to soar higher than anyone in a winged craft, by hitching a ride on stratospheric waves powered by the polar vortex.
His goal is to fly without engine to 27,500 metres.
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Koliko visoko može letjeti jedrilica?
Unutar jedrilice visoko iznad snijegom prekrivenih vrhova Anda u Patagoniji, spremnik je počeo ispuštati zrak.
Einar Enevoldson odmah je znao da se nalazi pred teškom odlukom.
Pokušavao je letjeti jedrilicom na rekordnoj visini od 15.000 metara i iznad nje - podvig koji je većina pilota smatrala nemogućim.
S njim u zrakoplovu bio je i milijarder Steve Fossett, koji je financirao pokušaj.
Zrak pod visokim pritiskom iz spremnika prolazio je kroz meke cijevi i ulazio u Fossettovo narančasto zaštitno odijelo.
Odijelo se napuhnulo i ukrutilo.
To se nije trebalo dogoditi na njihovoj visini.
Da se odijelo nastavilo i dalje puniti zrakom, Fossett bi bio imobiliziran satima...
Unutar jedrilice visoko iznad snijegom prekrivenih vrhova Anda u Patagoniji, spremnik je počeo ispuštati zrak.
Einar Enevoldson odmah je znao da se nalazi pred teškom odlukom.
Pokušavao je letjeti jedrilicom na rekordnoj visini od 15.000 metara i iznad nje - podvig koji je većina pilota smatrala nemogućim.
S njim u zrakoplovu bio je i milijarder Steve Fossett, koji je financirao pokušaj.
Zrak pod visokim pritiskom iz spremnika prolazio je kroz meke cijevi i ulazio u Fossettovo narančasto zaštitno odijelo.
Odijelo se napuhnulo i ukrutilo.
To se nije trebalo dogoditi na njihovoj visini.
Da se odijelo nastavilo i dalje puniti zrakom, Fossett bi bio imobiliziran satima.
Što je još gore, njegovo je odijelo moglo blokirati kontrole pa bi bilo nemoguće sigurno prizemljiti zrakoplov.
Pa ipak, dok se zima na jugu približavala kraju, ovo je mogla biti njihova posljednja prilika za let.
Enevoldson, koji je u to vrijeme imao 74 godine, proveo je 15 godina u pripremama za ovaj let, a desetljećima je sanjao o tome.
Kada bi samo mogli doći dovoljno visoko to bi dokazalo njegovu teoriju da i jedrilica može dospjeti visoko u stratosferu.
Povratak bi značio veliko razočaranje ali je bilo rizično nastaviti.
To je bilo 2006. godine.
Ovaj je let bio dio odvažnog plana po nazivu "Projekt Perlan".
Enevoldson procjenjuje da je pronašao način za put u veće visine od bilo koga u letjelici s krilima, hvatanjem stratosferskih valova kojima snagu daje polarni vrtlog.
Njegov je cilj letjeti bez motora do visine od 27.500 metara.
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Pushing back the limits of aeronautical exploration
Up there, the air pressure is less than 1 per cent of the pressure at sea level.
That's equivalent to the surface of Mars, and too thin to support the mass of almost any crewed plane.
So the team is building a winged craft unlike any before - a cross between a glider and a space capsule that will be light and fast enough to fly at this extreme altitude.
After years of planning, setbacks and tragedy, this project is poised to push back the limits of aeronautical exploration.
The official altitude record for a sustained horizontal flight in a piloted aircraft is 22,500 metres, set in a Lockheed U-2 aircraft 23 years ago.
Other craft have gone even higher into the stratosphere, but they had no wings...
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Pomicanje granica zrakoplovnih istraživanja
Gore u visinama tlak zraka iznosi manje od 1 posto tlaka na razini mora.
To je ekvivalentno tlaku na površini Marsa, a zrak je previše rijedak kako bi podržavao masu praktički bilo kojeg zrakoplova s posadom.
Stoga tim gradi zrakoplov s krilima koji se razlikuje od svih dosad viđenih - kombinacija je jedrilice i svemirske kapsule, a bit će lagan i dovoljno brz kako bi letio na ovoj ekstremnoj visini.
Nakon nekoliko godina planiranja, odgoda i tragedije, ovaj je projekt spreman za pomicanje granica zrakoplovnih istraživanja.
Službeni visinski rekord za kontinuiran vodoravan let zrakoplova s pilotom je 22.500 metara, postavljen u zrakoplovu Lockheed U-2 prije 23 godine.
Druge su letjelice išle čak i više u stratosferu, ali nisu imale krila...
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World's tallest waves
Enevoldson was convinced that this was wrong.
And in the early 1990s he found a crucial evidence to support his theory.
He was in his 50s at the time, with 13 world records to his name accrued during decades as a pilot for the US air force, RAF and NASA.
While visiting the Institute for Atmospheric Physics in Germany, a picture pinned to the wall caught his eye.
The lab director explained that it was taken by lidar, a radar mounted on a research plane and pointed upwards at the sky above Sweden's far north...
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Najviši valovi na svijetu
Enevoldson je bio uvjeren da je to pogrešno.
A početkom 1990-ih godina pronašao je ključni dokaz koji je podržavao njegovu teoriju.
U to je vrijeme bio u svojim 50-tim godinama, a priznato mu je 13 svjetskih rekorda tijekom nekoliko desetljeća koje je proveo kao pilot američkog ratnog zrakoplovstva, RAF-a i NASA-e.
Prilikom posjete Institutu za atmosfersku fiziku u Njemačkoj, za oko mu je zapela slika obješena na zid.
Direktor laboratorija mu je objasnio da je slika proizvedena uz pomoć lidara, radara ugrađenog na istraživački zrakoplov i usmjerenog gore prema nebu iznad Švedske na dalekom sjeveru..
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The first attempt
And so a decade later, Enevoldson and Fossett found themselves high above Argentina.
Their glider was named Perlan 1, after the picture of clouds in Germany.
To avoid having to build an expensive pressurised cabin, they had borrowed spacesuits from Enevoldson's old buddies at NASA.
It was the second day in a row that Fossett's suit had malfunctioned.
Enevoldson opened the air brakes and tipped the glider's nose toward Earth.
Mission was almost aborted, but they decided to try once more.
Suddenly, there it was.
The magnificent wave carried them upwards.
Later, GPS and meteorological models would show that Enevoldson and Fossett were travelling from the crest of one wave to the bottom of a taller adjacent one.
The crucial manoeuvre allowed them to burst into the stratosphere and set the world record for glider altitude...
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Prvi pokušaj
I tako su se deset godina kasnije Enevoldson i Fossett našli visoko iznad Argentine.
Njihova je jedrilica nazvana Perlan 1, prema fotografiji oblaka u Njemačkoj.
Kako bi izbjegli potrebu za izradom skupe kabine pod tlakom, posudili su svemirska odijela od Enevoldsonovih starih prijatelja iz NASA-e.
To je bio već drugi dan za redom da je Fossettovo odijelo bilo neispravno.
Enevoldson je otvorio zračne kočnice i usmjerio vrh nosa jedrilice prema Zemlji.
Misija je zamalo prekinuta, ali su odlučili pokušati još jednom.
Odjednom, bio je tu.
Veličanstveni val nosio ih je prema gore.
Kasnije su GPS i meteorološki modeli pokazali kako su Enevoldson i Fossett putovali od vrha jednog vala do dna višeg susjednog vala.
Taj im je ključni manevar omogućio uzlet u stratosferu i postavljanje svjetskog visinskog rekorda za jedrilice...
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To the edge of space
Today, once a month, Enevoldson makes a 9-hour drive north from his home near Berkeley, California, to a small town called Bend, Oregon.
His destination is a small, private airfield with five unmarked hangars.
Inside, sparks fly, you can hear drills as they pierce through metal and workers lay tacky carbon-fibre sheets into moulds.
This is "Windward Performance".
Greg Cole, the company's owner, is an aeronautical engineer, designer, craftsman and above all a perfectionist.
That's why Enevoldson chose him and his team to build the plane that will take him to 27,500 metres, named Perlan 2.
Cole's team is building almost every component, from the fuselage to the 13-metre-long wings...
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Put do ruba svemira
Danas, jednom mjesečno, Enevoldson vozi 9 sati u smjeru sjevera od svoje kuće u blizini grada Berkeley u Kaliforniji do malog grada po nazivu Bend u Oregonu.
Njegovo je odredište mala privatna zračna luka s pet neobilježenih hangara.
Unutra lete iskre, čuju se svrdla kako buše kroz metal, a radnici polažu ljepljive listove ugljičnih vlakana u kalupe.
To je tvrtka "Windward Performance".
Greg Cole, vlasnik tvrtke, zrakoplovni je inženjer, projektant, obrtnik i iznad svega perfekcionist.
To je razlog zbog kojeg je Enevoldson izabrao njega i njegov tim za izgradnju zrakoplova koji će ga dovesti na 27.500 metara visine, nazvanog Perlan 2.
Coleov tim izrađuje gotovo sve komponente, od trupa do 13 metara dugih krila...
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Perlan 2
Perlan 2 is a cross between a glider and a space capsule.
Its cabin is not only pressurised, it is completely sealed.
For safe crewed flight at high altitudes, jet planes pressurise their cabins by constantly sucking in outside air, but that is not an option for Perlan 2 since it has no engine.
Instead, it will use compacted air stored in its tail to adjust the pressure in the cabin.
The pilots will breathe from a separate tank.
Wings and fuselage are designed to make Perlan 2 go fast at high altitudes.
The higher you climb, the faster you have to go.
Fly too slow and not enough air molecules flow around the wings to keep you aloft.
But as you fly faster, two factors can create drag on the wings, slowing you down...
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Perlan 2
Perlan 2 je kombinacija jedrilice i svemirske kapsule.
Njegova je kabina ne samo pod pritiskom već i potpuno hermetički zatvorena.
Kako bi let s posadom na velikim visinama bio siguran, mlazni zrakoplovi svoje kabine drže pod pritiskom stalnim usisavanjem vanjskog zraka, ali za Perlan 2 to nije opcija budući da nema motor.
Umjesto toga će koristiti komprimirani zrak pohranjen u svom repu za prilagodbu tlaka u kabini.
Piloti će udisati zrak iz odvojenog spremnika.
Krila i trup projektirani su kako bi Perlan 2 na velikim visinama putovao brzo.
Što se više penjete, brže morate ići.
Ako letite presporo ne postoji dovoljan protok molekula zraka oko krila koji bi vas održao u zraku.
Ali ako letite brže, dva faktora mogu stvoriti otpor na krilima i usporiti vas...
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A unique wing design
To avoid these problems, Cole came up with a unique wing design.
It looks like every other glider wing to most people, but is very different.
Its leading edge, for instance, is fatter than a normal glider wing and the tail end of the wing turns down slightly.
"It's very subtle but it's actually a significant difference", says Drela.
"The Perlan airfoil is similar to something that you would find on a small radio-controlled glider".
Cole's wing could fly on Mars, so it's not out of the question that the design will find its way onto other planes, and even spacecraft...
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Jedinstveni dizajn krila
Kako bi izbjegao ove probleme, Cole je osmislio jedinstveni dizajn krila.
Većini ljudi ono izgleda kao i svako drugo krilo jedrilice, ali je vrlo različito.
Na primjer, njegov je prednji rub deblji od normalnog krila jedrilice, a stražnji kraj krila skreće malo prema dolje.
"Ovo je vrlo suptilno, ali je u stvari značajna razlika", kaže Drela.
"Perlanov je aerodinamički profil sličan nečemu što možete naći na malim jedrilicama na daljinsko upravljanje".
Coleovo bi krilo moglo letjeti i na Mars, pa nije nemoguće da će ovaj dizajn dospjeti i u druge zrakoplove, pa čak i svemirske letjelice...
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Atmospheric waves
The hope is that the research plane will fly in the same airspace, at the same time, providing the latest, most accurate data.
In return, the meteorologists are keen for Perlan 2 to collect "in situ" data at altitudes they cannot reach on their own.
They are particularly interested in what happens when atmospheric waves "break", and why it happens.
Breaking waves are the principal driver of air movement in the stratosphere, and if weather models do not represent them properly, air flows can start moving in entirely the wrong direction in computer simulations.
The researchers also want to find out why more stratospheric waves are being generated in this region than anywhere else in the world...
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Atmosferski valovi
Nadaju se da će istraživački zrakoplov letjeti u istom zračnom prostoru, istovremeno pružajući najnovije i najtočnije podatke.
Zauzvrat, meteorolozi žele da Perlan 2 prikupi podatke "in situ" na visinama koje su njima nedostižne.
Posebno su zainteresirani da otkriju što se događa kada se atmosferski valovi "slome" i zašto se to događa.
Valovi koji se slamaju glavni su pokretač strujanja zraka u stratosferi, a ukoliko ih vremenski modeli ne predstavljaju pravilno, struje zraka se mogu početi kretati u sasvim pogrešnom smjeru u računalnim simulacijama.
Istraživači također žele saznati zbog čega se u ovom području stvara više stratosferskih valova od bilo koje druge lokacije na svijetu...
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