Space Elevator

[Duro Kotulic Bunta]

Takze o nieco vyse mesiaca sa uskutocni dalsia vedecka konferencia venovana vesmirnemu vytahu. Zaujimavou skutocnostou je napr. to, ze sponzorom konferencie je Microsoft .
Odznie tam viacero zaujimavych prednasok, napr. o najaktualnejsom statuse vyvoja lana (tether-u), ci ekonomickych aspektoch, atd...

Pre tych, ktori nevedia, co to vesmrny vytah presne je, odporucam ako uvod tento clanok v slovencine.

[Honza]

Bude k dispozici alespon audio zaznam?
Koukal jsem na program (vypada zajimave), je to Open to the Public, ale osobne se z pochopitelnych duvodu nezucastnim...

[Duro Kotulic Bunta]

Zatial neviem, Marc Boucher (ktory ma na starosti web www.spaceelevator.com) vacsinou poziada autorov prispevkov na tychto konfrenciach o povolenie dat to na web, takze verim, ze to bude aj tentokrat.
Viacero zaujimavych prispevkov z prechadzajucich konferencii uz na www.spaceelevator.com je.

Anyway, ak bude nieco zaujimave verejne pristupne, urcite sa na to pozriem z zreferujem, pripadne napisem Marcovi ze kedy (a ci) budu info k dispozicii.

[Duro Kotulic Bunta]

Popularizacny clanok o vytahu sa objavil teraz v oktobri na CNN - pekny pocin.
http://www.cnn.com/2008/WORLD/europe/10 ... pstoryview

Nie su v nom ale ziadne prevratne novinky, okrem tej, ze v Japonsku sa do toho zahryzla skupina asi 100 vedcov/inzinierov (koniec koncov, uhlikove nanotrubicky su japonsky vynalez).
Odhaduju, ze okolo roku 2030 by sa mohol zacat vytah stavat (ze budu vyriesene problemy ohladom vyroby dostatocne dlheho a pevneho vlakna z nanotrubic). Bohuzial - a to je pretrvavajuci problem - tito vedci nedostavaju za svoj vyskum/vyvoj vytahu plat, takze to robia popri svojej hlavnej vedeckej praci.
Takze neprekvapilo by ma, ak by rok 2030 bol pri takomto sposobe privelmi optimisticky.

V kazdom pripade, vyvoj ide dopredu, aj ked pomaly a s malo peniazmi.
Asponze NASA ma sutaz o 4 miliony $ na dizajn.

[Kiwi]

No zaujalo ma hlavne toto:
It is not enough that other fibers be able to take over the load of a failed strand — the system must also survive the immediate, dynamical effects of fiber failure, which generates projectiles aimed at the cable itself. For example, if the cable has a working stress of 50 GPa and a Young's modulus of 1000 GPa, its strain will be 0.05 and its stored elastic energy will be 1/2 × 0.05 × 50 GPa = 1.25×109 joules per cubic meter. Breaking a fiber will result in a pair of de-tensioning waves moving apart at the speed of sound in the fiber, with the fiber segments behind each wave moving at over 1,000 m/s (more than the muzzle velocity of a standard .223 caliber (5.56 mm) round fired from an M16 rifle). Unless these fast-moving projectiles can be stopped safely, they will break yet other fibers, initiating a failure cascade capable of severing the cable. The challenge of preventing fiber breakage from initiating a catastrophic failure cascade seems to be unaddressed in the current literature on terrestrial space elevators. Problems of this sort would be easier to solve in lower-tension applications (e.g., lunar elevators).

[Duro Kotulic Bunta]

No zaujalo ma hlavne toto:
It is not enough that other fibers be able to take over the load of a failed strand — the system must also survive the immediate, dynamical effects of fiber failure, which generates projectiles aimed at the cable itself. For example, if the cable has a working stress of 50 GPa and a Young's modulus of 1000 GPa, its strain will be 0.05 and its stored elastic energy will be 1/2 × 0.05 × 50 GPa = 1.25×109 joules per cubic meter. Breaking a fiber will result in a pair of de-tensioning waves moving apart at the speed of sound in the fiber, with the fiber segments behind each wave moving at over 1,000 m/s (more than the muzzle velocity of a standard .223 caliber (5.56 mm) round fired from an M16 rifle). Unless these fast-moving projectiles can be stopped safely, they will break yet other fibers, initiating a failure cascade capable of severing the cable. The challenge of preventing fiber breakage from initiating a catastrophic failure cascade seems to be unaddressed in the current literature on terrestrial space elevators. Problems of this sort would be easier to solve in lower-tension applications (e.g., lunar elevators).

Zaujimave, konecne rozumny nazor ktory nespochybuje fyzikalne principy vytahu, ale hlada racionalne nedostatky.
Kde si nasiel tento text? V clanku ani v prvych par stovkach komentarov som ho nevidel...

Anyway, nie je pravda, ze sa tymto problemom nikto nezaoberal, pamatam si jeden prispevok z niektorej z konferencii venovanyvh vytahu, kde sa zaoberali aj tymto. Mam dojem, ze tento problem sa da vyriesit mikrodizajnom lana - ze vlakna nebudu rovnobezne ale roznym sposobom prepletene, a "zaistene".
Detaily si vsak nepamatam a ani konkretnu referenciu na danu prednasku.
V kazdom pripade, nie je to vec, ktorou sa vedci nezaoberaju a na ktory by zabudli, naopak, myslim, ze na toto uz upozornoval Bred Edwards hned v pociatkoch, pretoze kazdemu bolo jasne, ze potencialna energia ulozena v napnutom lane je obrovska...

[Hefto99]

Postavia výťah do kozmu?

[Duro Kotulic Bunta]

Pekny pocin, aj ked pohon vytahu je len sekundarny problem - najskor treba vyriesit material lana, inak sa vozitka nebudu mat po com splhat.
Skoda, ze financovanie vyvoja pokrivkava.. (ale nie je to nic prekvapujuce, je to prilis riskantna a velka investicia)

[slavko.sk]

Pekny pocin, aj ked pohon vytahu je len sekundarny problem - najskor treba vyriesit material lana, inak sa vozitka nebudu mat po com splhat.
Skoda, ze financovanie vyvoja pokrivkava.. (ale nie je to nic prekvapujuce, je to prilis riskantna a velka investicia)

Konecne som objavil zaujimavy BLOG, skoda ze autor asi nema moc casu na nove clanky a dakujeme mu ze sa venuje aspon nam - http://bunta.blog.sme.sk/c/41881/Vesmir ... topia.html !!!

[Kiwi]

Duro pise zaujimovo, keby z tych 50 000 ludi, co si precitalo jeho clanky aspon 10 % spustilo boinc,
to by bola parada.

[slavko.sk]

Duro pise zaujimovo, keby z tych 50 000 ludi, co si precitalo jeho clanky aspon 10 % spustilo boinc,
to by bola parada.

Akiste.

[Duro Kotulic Bunta]

Konecne som objavil zaujimavy BLOG, skoda ze autor asi nema moc casu na nove clanky a dakujeme mu ze sa venuje aspon nam - http://bunta.blog.sme.sk/c/41881/Vesmir ... topia.html !!!

Ja dakujem.
To boli este casy, ked som sa mohol venovat a vydavat energiu aj na nieco ine ako len na zabezpecovanie zivobytia pre rodinku

[Duro Kotulic Bunta]

Takze maly update co sa tyka situacie okolo vesmirneho vytahu - teraz v decembri 2009 bola zorganizovana dalsia konferencia (Carbon NanoTube Tether Design and Lunar Industrialization Challenges LUXEMBOURG Dec 5-6, 2009) s velmi zaujimavymi temami tykajucimi sa (okrem ineho) vytahu a vyvoja technologii potrebnych na jeho skonstruovanie.
Su k dispozicii abstrakty prispevkov:

Download Book of Abstracts part1 (.pdf)
Download Book of Abstracts part2 (.pdf)
Download Book of Abstracts part3 (.pdf)
Summary Report on EuroSpaceward's 3rd International Conference (.pdf)

Urcite si to prestudujem v blizkej dobe a ak nemate cas/chut citat, ak budu naozaj zaujimave zavery, tak napisem/zosumarizujem v tomto threade..

[Honza]

No je fakt, ze se to i po 40 letech cele toci kolem cenove dostupne moznosti vynaset [minimalne] na obeznou drahu co je potreba.

Docela jsem zvedav na kveten 2010, kdyz bude dalsi kolo souteze. Rychlost 5m/s v 1 km se nezda moc, ale je treba zvysovat latku postupne.

Vyroba natotrubicek zatim 5cm dlouha? No kdyz umeji spojit 1mm rychlosti rustu 50km/den, to uz zni lepe.
Je tam dost dalsich zajimavych cisel.

Souteze vypadaji vtipne - vyhrabat behem 30 minut 150 kg hmoty a to robotem, ktery nebude vazit vic jak 80kg a bude mit vsechnu energii na sobe. Jo, jak skladovat energii...

[Kiwi]

Zaujimave ze kazdeho zaujima len cena. Ale vraky B52 a ineho podobneho haraburdia nikoho nezaujima ?
Energiu vedel uz aj Tesla posielat, len nemal laser.