Venus Climate Orbiter "AKATSUKI"(PLANET-C,"Акацуки"), IKAROS, UNITEC-1, WASEDA-SAT2, Negai-Star, KSAT – H-2A – 21.05.2010 01:58 ЛМВ

[Salo]

Ждем релиз, мля... Все как-то хочется верить в лучшее...

http://www.jaxa.jp/countdown/f17/index_e.html
http://www.jaxa.jp/press/2010/12/20101208_akatsuki_e.html

Какой ещё мля... пресс релиз Вы ждёте?

[Tiger]

http://www.jaxa.jp/countdown/f17/index_e.html
http://www.jaxa.jp/press/2010/12/20101208_akatsuki_e.html

Какой ещё мля... пресс релиз Вы ждёте?

По всей видимости такой, где они подтвердят возможность дальнейшей работы с АМС.

[Salo]

http://mdn.mainichi.jp/mdnnews/news/20101208p2a00m0na010000c.html

Akatsuki probe overshoots Venus, attempt to be remade in 6 years [/size]

JAXA officials Junjiro Onoda, left, and Masato Nakamura announce the mission failure in a news conference on Dec. 8. (Mainichi)

"Akatsuki," a probe launched by the Japan Aerospace Exploration Agency (JAXA), failed to enter orbit around Venus, JAXA officials announced on Dec. 8.

Officials said that they believe that when Akatsuki was approaching its orbital entry point and engaged its reverse thruster, the thruster cut off before the probe could sufficiently reduce its speed, and the probe is now heading away from the planet.

Another attempt will be made to put Akatsuki into orbit around Venus when the probe comes close to the planet again in six years' time.

In the meantime, officials have set up an investigation team led by Junjiro Onoda, head of JAXA's Institute of Space and Aeronautical Science (ISAS), to more closely examine the cause of the failure.

The Akatsuki mission marks the second failure in a row for Japan to put a probe into orbit around another planet: Japan earlier failed to put its "Nozomi" probe, launched in 1998, into orbit around Mars.

Onoda and project manager Masato Nakamura gave the news of Akatsuki's failure at a conference at the ISAS.

"We decided to give up on injecting the probe into orbit this time," Onoda said. "For now we want our task team to examine the best measures for us to take in the future."

Nakamura added: "We apologize for being unable to meet everyone's expectations. The probe will come close to Venus again in six years. We want to try injecting it into orbit again at that time."

Akatsuki was launched in May. After coming within 550 kilometers of Venus on Dec. 7, it initiated its reverse thruster and started to change course. Soon afterwards, the probe began flying on the side of Venus opposite from Earth, and communications were cut off. A connection was later established via a low-gain antenna on the probe that is automatically activated in emergencies, but even then, for some time the probe's status remained largely unknown.

Officials suspect that soon after firing its thruster, the probe went into safe hold mode and turned off the thruster, preventing the probe from entering orbit and instead leaving it in orbit around the sun. After it was determined that Akatsuki could not make it back to Venus even if it used all its fuel, officials decided to abandon making any further orbit attempts this time.

The probe's reverse thruster needed to be fired for at least 9 minutes and 20 seconds, but appear to have stopped after only two to three minutes.

Akatsuki will again approach Venus in December 2016 and January 2017. Ordinarily it would end up about 3.7 million kilometers away from the planet, but its trajectory can be modified to bring it closer.

Akatsuki was designed to have a life of two years, but its batteries can last longer, and since 80 percent of its fuel remains, officials judged that another attempt is possible. However, since the probe will travel closer to the sun than Venus, officials fear it may suffer damage from heat or radiation.

[Salo]

http://forum.nasaspaceflight.com/index.php?topic=18950.msg669062#msg669062

Two minutes and 23 seconds after OME injection, X-axis was suddenly rotating 360 deg.

http://translate.google.com/translate?u=http%3A%2F%2Fjournal.mycom.co.jp%2Farticles%2F2010%2F12%2F09%2Fplanet-c_detail%2F&sl=ja&tl=en&hl=&ie=UTF-8

[Имxотеп]

http://forum.nasaspaceflight.com/index.php?topic=18950.msg669062#msg669062

Two minutes and 23 seconds after OME injection, X-axis was suddenly rotating 360 deg.

Плохой знак.
Возможно прогорело или лопнуло знаменитое керамическое сопло, тяга ДУ пошла куда-то вбок и закрутила аппарат.

[hecata]

http://forum.nasaspaceflight.com/index.php?topic=18950.msg669062#msg669062

Two minutes and 23 seconds after OME injection, X-axis was suddenly rotating 360 deg.

Плохой знак.
Возможно прогорело или лопнуло знаменитое керамическое сопло, тяга ДУ пошла куда-то вбок и закрутила аппарат.

Да и любые другие варианты - не лучше (в т.ч. совсем уж невероятное попадание частицы).

[hecata]

А можно поподробнее, что входит в PI и в fully burdened cost?

PI cost - разработка, изготовление КА и ПН, управление полетом, обработка научной информации и пр. Не входит - стандартный носитель и предполетное обслуживание, РИТЭГ(и). Впрочем существуют нюансы. Подробно здесь: http://nspires.nasaprs.com/external/viewrepositorydocument/cmdocumentid=214565/Discovery%2010%20DRAFT%20RELEASE.pdf

Спасибо!

[Tiger]

http://mdn.mainichi.jp/mdnnews/news/20101209p2a00m0na006000c.html

В JAXA не знают, что и думать. Пробные включения по пути на Венеру были нормальными. Они даже готовы столкновение с метеоритом в область этого самого сопла допустить.

[byran]

Ну так те коррекции были в пределах десятка секунд, а тут он через 2.5 минуты работы перегорел. Явно это дело "не имеющего аналогов керамического двигателя". Во общем экспериментаторы, решили двигатель проверить на своей АМС.  

[byran]

Хотя возможно даже выход главного двигателя это не смертельно. Пишут, что есть несколько микродвигателей ориентации.

http://en.wikipedia.org/wiki/Akatsuki_(probe)

Propulsion is provided by a 500 newton (N) bi-propellant, hydrazine / nitrogen tetroxide orbital maneuvering engine and 12 mono-propellant hydrazine reaction control thrusters, eight with 23 N thrust and four with 3 N.

Может их возможно задействовать для повторной попытки выхода на орбиту? Хотя похоже топливо разное.

[Salo]

http://www.yomiuri.co.jp/dy/features/science/T101209005839.htm

JAXA scratching head over Akatsuki failure[/size]

The Yomiuri Shimbun

The Akatsuki space probe suffered a sudden, dramatic loss of balance two minutes 23 seconds after commencing an unsuccessful attempt to enter orbit around Venus on Tuesday for an observation mission, the Japan Aerospace Exploration Agency said Wednesday night.

Although the cause of the sudden change in attitude has not yet been identified, experts suspect there was trouble with the probe's orbit maneuvering engine (OME), which produces the thrust that was intended to help the craft enter Venus' orbit.

The problem occurred while the OME was firing.

Akatsuki's OME thruster was equipped with a ceramic nozzle, the first ever use of such technology.

JAXA intends to try once more to inject Akatsuki into the orbit around Venus six years from now, when the probe will next come close enough to the planet.

However, many experts are concerned about a recurrence of Tuesday's mishap.

Retrofiring of the OME was intended to reduce the probe's velocity, such that it would be drawn by Venus' gravitational pull into the orbit of the planet.

The OME began firing at 8:49 a.m. Tuesday, according to JAXA. Although the probe's attitude "wobbled" a little at first, it soon stabilized, the agency said.

However, two minutes 23 seconds after beginning the maneuver, Akatsuki suddenly lost stability, turning in a forward somersault at a pace of one revolution per five seconds.

The probe automatically entered "safe-hold mode," stabilizing itself by rotating slowly to prevent damage.

JAXA suspects that during this time of recovery, operation of the OME was suspended.

"It's thought that a strong force acted on the body of the probe, causing it to lose attitude stability," Prof. Masato Nakamura, the Akatsuki project manager at JAXA, told a press conference Wednesday.
(Dec. 10, 2010)

[Salo]

http://www.yomiuri.co.jp/dy/features/science/T101209005121.htm

Suspected engine trouble casts shadow[/size]

Koichi Yasuda / Yomiuri Shimbun Staff Writer

Suspected engine trouble with the space probe Akatsuki has cast a shadow on the Venus explorer's fate.

At a press conference Wednesday night, scientists at the Japan Aerospace Exploration Agency suggested Akatsuki's orbital maneuvering engine (OME), or thruster, might have had problems with a ceramic nozzle, a factor that could endanger the probe's successful entry into orbit around Venus six years from now.

Akatsuki will next come close enough to Venus to have a chance of entering orbit between December 2016 and January 2017. Scientists reportedly plan to modify Akatsuki's path little by little for this to work. But even if a second attempt is possible, the probe must continue traveling in space for the next six years. During this period, the probe will be exposed to heat and radiation from the sun, which may result in device deterioration and the malfunction of electronic parts.

This also means the probe will have no problem securing electricity from the sun's rays, but the probe's batteries, essential for operating its cameras and communication tools, were only expected to last about 4-1/2 years after the explorer began orbiting Venus because it will alternate between sun and shade.

Furthermore, the batteries may deteriorate if they have to be used before entering orbit. In that case, even if the probe enters orbit around Venus at the earliest opportunity in December 2016, it may not function properly during the two-year exploration period.

Even if delayed, the mission will have some significance. Akatsuki is equipped with five cameras enabling it to observe clouds over Venus on an ongoing basis.

The mission's biggest goal is to explain the workings of Venus' atmosphere, which is known for storms blowing at the speed of 100 meters per second.

It is also aims to find out why Venus, despite displaying a similar size, mass and density to Earth, has turned into a scorched planet with extremely high surface temperatures.
(Dec. 10, 2010)

[Salo]

http://www.yomiuri.co.jp/dy/features/science/T101209004800.htm

Hopes dashed during 20-minute silence
[/size]
Masae Honma and Makoto Mitsui / Yomiuri Shimbun Staff Writers

The space probe Akatsuki's failure to go into orbit around Venus, the result of unexpected problems that occurred when the probe was out of communication with its handlers, shows that Japan still has a long way to go to achieve planetary exploration.

Akatsuki project leader Prof. Masato Nakamura of the Japan Aerospace Exploration Agency seemed completely confident in the middle of November, as the critical moment approached.

"We've done everything we can," Nakamura said.

Since its launch in May, Akatsuki had cleared all the scheduled tests of its equipment, including a 13-second test-firing of its main engine in June. The maneuvers to enter into orbit around Venus on Tuesday were carried out after all necessary preparations had been taken.

Everyone at JAXA was confident of success, but the attempt ended in failure.

The trouble occurred while Akatsuki was unable to communicate with its control room for about 20 minutes because it was on the far side of Venus.

The Venus climate orbiter's thruster was scheduled to retrofire for 12 minutes from 8:49 a.m. Tuesday, but it actually did so only for two to three minutes. JAXA is analyzing data sent from the probe to determine why.

"Each failed exploration attempt has a completely different cause. It highlights the difficulty of space exploration," said Prof. Hajime Hayakawa of JAXA, who is leading the project for a Mercury explorer scheduled to be launched in 2014.

Putting a probe into orbit around a planet while under the influence of that planet's gravity is a technically difficult feat. The former Soviet Union, which made significant achievements in exploring Venus, failed a number of times to put space probes into orbit around Mars during the 1960s and '70s.

There are two ways to approach a planet exerting a strong gravitational pull:

-- Strongly fire jets on the orbital maneuvering engine to enter orbit immediately.

-- Gradually adjust speed over a long period of time.

Though the first option allows an explorer to go into orbit around the planet quickly, the powerful firing of the engine tends to cause problems with the probe's equipment and position.

It also is impossible to make a second try.

The second option places less of a burden on the engine, but the longer time required means more risks, such as malfunctions resulting from solar flares.

"Both methods have merits and demerits," Hayakawa said. "There will always be unexpected problems no matter how much preparation is done on the ground. That's the difficulty of planetary exploration."

Failure a blow to space goals

The United States and the Soviet Union once were the only nations exploring other planets, but today an increasing number of countries are undertaking such projects.

Japan intends to become one of them, and Akatsuki's failure has dealt a serious blow to this goal.

Earlier this year, the Hayabusa space probe brought back samples of material from an asteroid, a first in the history of space exploration and proving to the rest of the world Japan's high level of technological achievement.

The Education, Culture, Sports, Science and Technology Ministry wants to promote this country's space industry overseas by boosting Japan's brand power through such successful missions. Akatsuki's failure may hinder these efforts.

To maintain its technological brand, this country must promptly determine why the attempt to go into orbit around Venus failed, so the explorer will be able to try again six years from now.

If JAXA can swiftly discover the cause and take the necessary measures to rectify the problem, it should help promote Japan's technology.

Satoshi Tsuzukibashi, head of the Industrial Technology Bureau of the Japan Business Federation (Nippon Keidanren), was positive about the future prospects of Japan's space industry.

"We can't always expect success when we explore a frontier," Tsuzukibashi said.

JAXA is aiming to launch a Mercury explorer and a follow-up to the Hayabusa probe in 2014. It also is considering launching explorers to Mars and Jupiter.

Despite the latest failure, the science and technology ministry is still seeking government funding for future space projects.

"Some countries respond to failure by boosting [their space development projects]," Senior Vice Minister Ryuzo Sasaki said at a press conference Wednesday.
(Dec. 10, 2010)

[Salo]

http://mdn.mainichi.jp/mdnnews/news/20101209p2a00m0na006000c.html

Akatsuki probe began unexpectedly spinning after firing thruster[/size]


The Akatsuki probe is thought to have spun in the direction indicated by the white arrows. The cone on the right side is part of the ceramic thruster. Image courtesy of JAXA, with modifications.

Japan's first attempt at a Venus probe, Akatsuki, fell into an unexpected rapid spin soon after beginning the reverse-firing of its thruster, which is thought to have caused it to enter into the "safe-hold mode" that stopped the thruster from reversing and prevented the probe from entering orbit, officials from the Japan Aerospace Exploration Agency (JAXA) announced on Dec. 8.

The unexpected spinning could have been the result of damage to the probe's thruster, a newly-developed "ceramic thruster."

On the morning of Dec. 7, as Akatsuki approached Venus, it began reverse-firing its thruster and adjusting its course to enter orbit, just as planned. Soon afterwards communication with Akatsuki was interrupted as it flew on the side of Venus opposite from Earth. Communications were restored about an hour and a half later, but in the meantime, the probe had entered safe-hold mode, which had shut off its reverse thruster before the probe's velocity had been reduced enough to enter Venus's orbit. Akatsuki ended up passing the planet.

Analysis of data sent by the probe has revealed that 2 minutes and 23 seconds after beginning the reverse-firing of its thruster, Akatsuki began relatively rapid spinning, at a rate of one turn every five seconds. JAXA scientists suspect that this is what caused the probe to enter its safe-hold mode.

"It seems to have been affected by a fairly strong force," surmised JAXA professor Masato Nakamura.

Akatsuki's ceramic thruster is a newly developed piece of equipment, but it showed no problems during tests at the end of June as the probe was on its way to Venus.

"During durability tests here on Earth, we determined that the thruster was tough, but because it is ceramic (not made of metal), it could have been damaged if something ran into it. The engine's thrust is very powerful, and if it blew sideways (because of damage) then that could have caused the probe to begin spinning," said Nakamura.

If the thruster was damaged, a second attempt to enter orbit when the probe approaches Venus in six years will be difficult.

"Right now we still don't know for sure what happened. We still want to reattempt an orbital entry," said Nakamura.

[Pavel]

Чтож. Вариантов, похоже, действительно нет. Двигатель треснул и аппарат закрутило. Так, что, думаю, нужно отбросить надежду на выход на орбиту и через 6 лет..  

Кстати, не было информации о плоскости поворота относительно Венеры? Она случаем, не ей не параллельна? В смысле, может во всем виноват перегрев от Венеры "снизу", и  охлаждение от космического пространства "сверху"? Напряжения накопились и вот результат..

[Pavel]

Венера камерой Акацуки...




http://www.isas.jaxa.jp/j/topics/topics/2010/1210.shtml

http://planetary.org/blog

[Leroy]

Венера камерой Акацуки...

Грустное фото!  :cry:

[dee34rt]

Венера камерой Акацуки...




http://www.isas.jaxa.jp/j/topics/topics/2010/1210.shtml

http://planetary.org/blog

Называется "здравствуй и прощай"

[sol]

2 Сало

Я жду релиз не на тему - что и почему случилось, а на тему - что делать дальше будем?

Это напишут очень нескоро - месяц минимум самураи мозговать будут. И что-то придумают - стопудово выжмут из аппарата что-нибудь.
Вплоть до смены пакета задач!

Как насчет пролета Меркурия за счет гравманевра у Венеры через 6 лет?

[Pavel]

2 Сало

Я жду релиз не на тему - что и почему случилось, а на тему - что делать дальше будем?

Это напишут очень нескоро - месяц минимум самураи мозговать будут. И что-то придумают - стопудово выжмут из аппарата что-нибудь.
Вплоть до смены пакета задач!

Как насчет пролета Меркурия за счет гравманевра у Венеры через 6 лет?

 Боюсь шансы минимальные. При любом раскладе для таких финтов ушами нужны коррекции, а с движком проблемы..