doar rusii "stiu" aerospatiale? se pare ca nu...

articol preluat de pe: http://www.esa.int/e...IE_index_0.html

Today experts from across the world meet at ESA to discuss how to best calculate spacecraft orbits. Even though the space age is now 49 years old, determining the optimal trajectories for spacecraft is a far from easy task.

People often have trouble deciding which is the best route to take on a car journey. In space the problems are much worse. Space missions are constrained by certain factors such as the thrust of the rocket used to launch the spacecraft, the celestial object you want to reach and the time at which you want to get there. When working out the best trajectories within such constraints, engineers all have different strategies.
"Ask ten engineers for the best orbit for a particular spacecraft and you'll get ten different ideas," says Dr Dario Izzo, a researcher on mission analysis in the Advanced Concepts Team at ESA's European Space and Technology Research Centre (ESTEC) in the Netherlands. Each one of these missions will be the best for a certain reason, so the question becomes: what's the best of the best? One of the proposed trajectories or another that no-one has thought of?  

In other words, orbits are like needles in a haystack. Search hard enough and you?ll find one, but is it the best one in the haystack? That?s where the new technique of global optimisation comes in. It is a method of handling complex problems with many variables that has lots of solutions. But there are many techniques for global optimisation and they are difficult to compare since they seldom use the same constraints when applied.

To compare and contrast different techniques, ESA's Advanced Concepts Team, supported by the European Space Operations Centre (ESOC), launched a competition. They issued a challenge to space engineers across the world to find an intercept trajectory that delivered as much energy as possible to the asteroid 2001 TW229.

Twelve teams, from the US, China, Russia and Europe submitted their respective best solution. Izzo's job was to rank the proposals according to how much energy each mission could impart to the asteroid. "The inspiration for this competition was asteroid deflection, a problem we have been working on quite thoroughly" says Izzo. Whilst asteroid 2001 TW229 presents no danger to Earth, issuing a call for trajectories simulated a step that would be taken in the event that a potentially dangerous asteroid were to be discovered. The key to the mission would be to deliver the largest push possible, in time for it to do the most good.




The winning trajectory from JPL
The top ranked trajectory went to a team from the United States? Jet Propulsion Laboratory (closely followed by two Spanish teams). Their amazing trajectory involved seven planetary flybys, mostly of the Earth but including Venus, Jupiter and Saturn that literally smashed the spacecraft into a head-on collision with the asteroid.

The teams will now meet in the Netherlands to discuss their individual approaches to the problem. "The response to the competition was excellent. At the meeting we will discuss the different methods used and identify the ones that have proven the most promising," says Izzo.

In fact, the response to the competition was so good that the Advanced Concepts Team also hope to run future competitions, to further stimulate research in the exciting field of mission analysis.

completez deoarece s-ar putea intelege ceva gresit...
nicidecum nu implicam ca uite rusii ce fraieri sunt :)
dupa cum se vede daca studiati si site-ul:    http://www.esa.int/g...s/goresults.htm

o echipa rusa a avut chiar o solutie interesanta. Si exista una plasata chiar pe locul 4 destul de aproape de castigatori. In asemenea probleme de optimizare e nevoie si de noroc. In plus sa nu uitam ca americanii au avut echipa destul de numeroasa comparativ cu cele rusesti. Rusii au specialisti de mare clasa pe portiunea de calcul de orbite/dinamica spatiala (si nu numai in acest domeniu).

Cu asta sper sa-mi fi spalat pacatele vizavi de o eventuala neintelegere a semnificatiei frazei mele. :)

Numeric

<<In fact, the response to the competition>>
De fapt, rusii nu stiu engleza !
Daca scrii in engleza deja ai pus o eticheta superioritate.

Imi place f. mult tehnica rusesca.
Mai bine vb. despre asta.

Edited by Gurban_Dan, 06 February 2006 - 18:08.

Eu as deschide un topic pentru pasionatii de aerospatziale, dar nu stiu unde.

cativa "americani" din echipa castigatoare :
Dr. Anastassios E. Petropoulos
Dr. Seungwon Lee
Dr. Chen-Wan L. Yen
si mai sunt cativa cu nume "suspecte".
Acum vreo doi ani, la facultate, un profesor ne-a aratat revista inginerilor motoristi americani(cam asa suna titlu) si peste 50% din articolele si studiile publicate aveau autori chinezi, japonezi, rusi..

Rusii fac lucruri de calitate. Atit ca cint cam puturosi. Ma rog, poate faci threadul si duscutam si despre Kliper ca Buran e deja istorie.

Asa cum am mentionat si intr-unul din primele mesaje, nu vroiam nicidecum sa zic "uite fraierii de rusi"... doream doar sa trag de limba populatia de pe forum sa-si exprime parerile. Sper ca nu am deranjat pe nimeni.

Tehnologia aerospatiala ruseasca a fost de inalta calitate, dar sa nu uitam ca si astazi se folosesc metode si tehnici din anii 1960-1970. Acest lucru a fost sesizat chiar de directorul companiei Energhia si de aceea doresc un upgrade al flotei spatiale prin introducerea noilor capsule spatiale Kliper. Ramane de vazut daca aceasta strategie le va aduce si succes. Sa nu uitam ca in domeniul spatial rusii inca au mari gauri financiare. Lucrurile din punctul asta de vedere nu sunt chiar roze desi companiile aerospatiale au fost privatizate si unele dintre ele au inceput sa returneze bani sub forma de "profit"...

In plus in general industria aerospatiala returneaza bani in decurs de 10-15 ani... nu este chiar o industrie usoara de genul celei metalurgice sau a celei de imbracaminte, incaltaminte... nu vreau sa generalizez si sa zic ca alte industrii sunt simple dar exista o proprietate deosebita a celei aerospatiale care o face sa nu fie neaparat atractiva tuturor investitorilor... tocmai aici rusii lucreaza de zor cautand sa atraga proiecte internationale si sa faca industria aerospatiala o adevarata industrie ce produce bani si nu doar absoarbe bani ca o gaura neagra.

Numeric

Ninja, on Feb 8 2006, 21:54, said: