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quarta-feira, 26 de Novembro de 2008 | 15:16 Imprimir Enviar por Email

Irão testa «com sucesso» foguete espacial «Kavosh 2»


O Centro Espacial iraniano lançou hoje "«om sucesso» um foguete espacial baptizado de «Kavosh 2» como parte de um programa estratégico nesta área, noticiou a agência de notícias Fars.
O foguete, classificado como «de pesquisa», realizou um vôo de poucos minutos e regressou a Terra, onde aterrou com a ajuda de um pára-quedas.

Segundo a Fars, o teste realizado hoje tinha como objectivo testar o registo e transmissão de informações, bem como os mecanismos de carga e desprendimento do aparelho, cujos resultados foram «satisfatórios».

O «Kavosh 2» é composto por um bloco de carga, um laboratório espacial e um sistema de recuperação.

Em Fevereiro, o Irão lançou o primeiro foguete de fabrico nacional e em Agosto colocou em órbita o seu primeiro satélite, que Teerão afirma ter apenas fins civis, perante a desconfiança dos EUA pela corrida espacial iraniana.

Did launcher's history foreshadow satellite crash?

Jeff Hecht, contributor

After NASA's $273 million Orbiting Carbon Observatory failed to reach orbit on Tuesday, some of us at New Scientist started to wonder if the choice of launch vehicle was the problem. After all, the Taurus launcher hasn't flown in nearly five years, and one of its previous seven launches failed in 2001.
Early versions of the launcher used Cold War-era Peacekeeper missiles as the first stage of the rocket. But that was not the case this time. In four of the last five launches - including the launch failure in 2001, the first stages used modern Castor 120 engines from ATK Thiokol.

In any case, the first stage does not seem to be the culprit in this case. NASA and Orbital Sciences, which built both the launcher and the satellite, are convening inquiry boards to figure out exactly what went wrong and how to fix it. But they say the immediate cause of the failure was the fairing that covered the satellite during launch.

The first and second stages of the Taurus XL rocket fired flawlessly, and the third ignited as planned after the second stage separated.

Seven seconds after the third stage ignition, the clamshell-shaped fairing was supposed to split apart and drop towards the ground. "But . . . we started getting indications the fairing did not separate," John Brunschwyler, Taurus program manager at Orbital Sciences, said in a post-launch news briefing. They knew for sure when the booster failed to accelerate after it was supposed to have shed the fairing.

Fairings are standard in spacecraft launches; they cover the payload at the top of a rocket to improve aerodynamics and prevent wind damage as the rocket rises through the lower atmosphere. Once the rocket rises into the upper atmosphere, the fairing becomes dead weight and is jettisoned. Dropping the fairing reduces payload weight significantly, so the third stage should then have accelerated faster. But with the fairing still on board, the final stages of the booster lacked the power to reach orbit and fell back to Earth.

Rocket engineers have tried and true ways to jettison spent boosters and unneeded fairings. Two pairs of electrical pulses were supposed to fire explosive bolts that opened the top of the clamshell covering OCO. Then two more pairs of pulses should have fired other bolts to split apart its base joint 80 seconds later. "We have confirmation that the correct sequence was sent by the software," and onboard electronics seemed to be working, Brunschwyler said. He reported no previous problems with the fairing design.

Indeed, even though the Taurus launch that failed in 2001 used the same 63-inch fairing as the OCO launch, the fairing was not implicated in that case. At that time, a Taurus rocket - configured differently than the one that launched OCO - veered off course after the separation of its first stage. That prevented NASA's Quick Total Ozone Mapping Spectrometer and a private imaging satellite called OrbView-4 from reaching orbit.

So this failure may simply serve as a reminder that launching things into space is no easy feat - it is, after all, rocket science. Something can always go wrong, and sometimes it's a component that has given no problem before.

Noticia de: http://www.newscientist.com

cabeça de martelo escreveu:Afinal o que é que vai substituir os vaivem espacial?

cabeça de martelo escreveu:Afinal o que é que vai substituir os vaivem espacial?

cabeça de martelo escreveu:Obrigadão pelas infos.

Eu estava à espera de algo mais na linha do Vaivém Espacial e não foguetões espaciais. Já fiquei foi com algumas coisas para ler:

http://www.nasa.gov/pdf/211102main_eelv_faq.pdf

http://www.nasa.gov/pdf/256922main_Dire ... _62508.pdf

Iran plans satellite launches next year



Tehran, Iran (CNN) -- Iran plans to launch satellites into orbit early in the new year, its defense minister told the semi-official Fars news agency Wednesday.
"This satellite, which was built by Iranian scientists, is a big step for the continued presence of Iran in space and for taking advantage of the opportunities offered in this field," Gen. Ahmad Vahidi said.
The launches of the Tolou satellites -- which means "sunrise" in Farsi -- are scheduled to take place in February and March, according to Fars.
Iran launched its first satellite, Omid, in February, an event that President Mahmoud Ahmadinejad hailed at the time as a "source of pride" for the Islamic republic.
The U.S. State Department expressed "grave concern" over the launch.
"Developing a space launch vehicle that could ... put a satellite into orbit could possibly lead to development of a ballistic missile system," State Department deputy spokesman Robert Wood told reporters. "So that's of grave concern to us."
The Pentagon called the February launch "clearly a concern of ours."
"Although this appears to be satellite, there are dual-use capabilities that could be applied to missiles, and that's a concern to us and everybody in region," Defense Department spokesman Geoff Morrell said at the time.
For Iran, the planned launches are an important step for its military.
"Using these modern technologies, Iran's armed forces are capable of catching the enemies off guard, identifying their software and hardware potential and depriving the enemy of movement and maneuverability," Vahidi told Fars.
The development comes as the international community considers additional sanctions against Iran should Tehran not answer questions about its nuclear program. Western powers fear Iran is intent on developing nuclear weapons, an allegation Tehran denies.

http://www.militaryphotos.net/forums/sh ... p?t=171186