SpaceX Falcon 9

Автор ATN, 08.09.2005 20:24:10

« назад - далее »

0 Пользователи и 2 гостей просматривают эту тему.

Astro Cat

#15840
ЦитироватьЗловредный пишет:
SLC-40 наверно не только отремонтируют, но и заодно проапгрейдят  :)  
Покроют все жаропрочными материалами? )))

Зловредный

Ну должны же были они чему-то научиться за эти годы!
Гробос-Фунт

Max Andriyahov

МакГрегор сегодня:
@ about 20:00 last evening we had the longest burn in McGregor. I didn't measure it but I'm pretty sure it was in the 5-6 minute range & very loud & shook the house. We are literally getting our house shook apart. We did have perfect weather to hear it. Clear dry air with no overcast, ie. temperature inversion. Anybody know what's going on?

Прожиг 5 минут? Но зачем?

Apollo13

На 5 минут в баках ступени топлива не хватит. Это наверно отдельный двигатель какой-то.

LRV_75

#15844
ЦитироватьApollo13 пишет:
На 5 минут в баках ступени топлива не хватит. Это наверно отдельный двигатель какой-то.

Falcon 9 Full Thrust

Тяга второй ступени в вакууме возросла до 934 кН, удельный импульс в вакууме — 348 с, время работы двигателя увеличилось до 397 секунд
Главное не наличие проблем, главное способность их решать.
У каждой ошибки есть Имя и Фамилия

Зловредный

ЦитироватьGeorgea пишет:
ЦитироватьSalo пишет:
There are ample rumors in the spaceflight community about how SpaceX has struggled to make its existing, returned rockets ready for flight.
Кто-нибудь знает подробности? Что за слухи о проблемах с повторным запуском?
Появилось вот это:
https://forum.nasaspaceflight.com/index.php?topic=42218.msg1637935#msg1637935
ЦитироватьWow. Quite a clickbait title. I'm pretty sure the turbopump cracks have been reported here some time ago. If I remember right, they were able to identify the problem after examining the landed boosters. I expect SpaceX is already working on a solution.
И ещё:
https://forum.nasaspaceflight.com/index.php?topic=42218.msg1637941#msg1637941
ЦитироватьWSJ - Congressional Investigators Warn of SpaceX Rocket Defects
Government Accountability Office's preliminary findings show persistent cracking of vital propulsion-system components

"Congressional investigators are raising new safety concerns about Space Exploration Technologies Corp.'s plans for future manned launches, citing persistent cracking of vital propulsion-system components, according to government and industry officials familiar with the details. The Government Accountability Office's preliminary findings reveal a pattern of problems with turbine blades that pump fuel into rocket engines, these officials said. The final GAO report, scheduled to be released in coming weeks, is slated to be the first public identification of one of the most serious defects affecting Falcon 9 rockets.

The crack-prone parts are considered a potentially major threat to rocket safety, the industry officials said, and may require redesign of what are commonly called the Falcon 9's turbopumps. The National Aeronautics and Space Administration, they said, has warned SpaceX that such cracks pose an unacceptable risk for manned flights.
A SpaceX spokesman didn't have any comment.

The red flags are appearing as entrepreneur Elon Musk's closely held company has delayed for at least two weeks its first unmanned launch from a newly renovated Cape Canaveral, Fla., pad, pending further tests of ground facilities. SpaceX's initial blastoff from the Kennedy Space Center's pad 39A—a historic site used to launch NASA's Apollo missions to the moon—is now scheduled no earlier than mid-February.

Taken together, the moves underscore technical and schedule challenges facing Southern California-based SpaceX as it seeks to accelerate its launch tempo. This year, the company aims to launch more than double the eight rockets it launched last year to meet commitments to NASA, and whittle away at a bulging backlog of delayed commercial missions. SpaceX's internal projections envision ramping up total launches to roughly one a week past the end of the decade, including at least a handful of its most-powerful Falcon Heavy boosters annually. Development of the Falcon Heavy is years behind schedule, but SpaceX hopes to conduct its maiden flight later this year.

Industry officials have known about problems with cracked blades on Falcon 9 versions for many months or even years. But cracks continued to be found during tests as recently as September 2016, Robert Lightfoot, NASA's acting administrator, confirmed in an interview with The Wall Street Journal earlier this week. NASA officials have been briefed on the focus of the GAO's preliminary findings. Mr. Lightfoot said "we're talking to [SpaceX] about turbo machinery," adding that he thinks "we know how to fix them." In the interview, Mr. Lightfoot said he didn't know if the solution would require a potentially time-consuming switch to bigger turbopumps.

[Remainder snipped]
Гробос-Фунт

Зловредный

https://forum.nasaspaceflight.com/index.php?topic=42218.msg1637997#msg1637997
Цитироватьhttp://www.theverge.com/2017/2/2/14490946/spacex-rocket-engine-safety-defect-congressional-investigation-wsj-report

Quote
ЦитироватьHowever, SpaceX argues that it has designed its engines so that they can withstand cracking in the turbines, but it's also working on ways to get rid of the problem. "We have qualified our engines to be robust to turbine wheel cracks," John Taylor, a SpaceX representative, tells The Verge. "However, we are modifying the design to avoid them altogether. This will be part of the final design iteration on Falcon 9. SpaceX has established a plan in partnership with NASA to qualify engines for [crewed] spaceflight."
Гробос-Фунт

LRV_75

#15847
Перенес в тему SpaceX
Главное не наличие проблем, главное способность их решать.
У каждой ошибки есть Имя и Фамилия

Salo

#15848
http://www.spacepolicyonline.com/news/wall-street-journal-draft-gao-report-finds-problems-with-spacex-turbine-blades#.WJQRrMpg8MA.twitter
ЦитироватьWall Street Journal: Draft GAO Report Finds Problems with SpaceX Turbine Blades
Marcia S. Smith
Posted: 02-Feb-2017
 Updated: 03-Feb-2017 12:15 AM
 
The Wall Street Journal (WSJ) reported today that a draft study from the Government Accountability Office (GAO) reveals problems with the turbine blades on SpaceX rockets that could impact safety and therefore the schedule for commercial crew launches.  A GAO spokesman told SpacePolicyOnline.com that he could not confirm the contents of the report because it is only in draft form.
WSJ's Andy Pasztor cites unnamed "government and industry officials familiar with the details of the report" as the sources of the story that GAO found "persistent cracking" of  turbine blades in SpaceX Falcon 9 rocket engines.  Pasztor goes on to say that NASA "has warned SpaceX that such cracks pose an unacceptable risk for manned flights."
SpaceX did not respond to a request from SpacePolicyOnline.com for comment on the WSJ story by press time. Pasztor quotes an unnamed SpaceX spokesman as saying that the company is modifying its design to avoid the cracks.
GAO Public Affairs Managing Director Chuck Young could confirm to SpacePolicyOnline.com only that GAO has work underway in response to language in the House Appropriations Committee's report to accompany the FY2016 Commerce-Justice-Science appropriations bill (H.R. 2578 ). He said he could not comment on the contents of a draft report and GAO had not provided copies to reporters.  The final report is expected to be released by the end of the month.
Спойлер
GAO is the investigative arm of Congress.  It typically allows the agency it is reviewing to comment on drafts and incorporates the comments into its final report as appropriate.  It also publishes the text of the agency's response as an appendix.
SpaceX and Boeing were sel ected by NASA in 2014 to complete development of crew space transportation systems to take astronauts to and from the International Space Station (ISS) through public-private partnerships. The concept is that the government and the companies both fund the development costs for systems that will be owned and operated by the companies, while the government guarantees to purchase a certain number of launches from them.  NASA does this already for robotic cargo spaceflights that resupply the ISS -- commercial cargo.  SpaceX and Orbital ATK currently provide commercial cargo services for NASA and Sierra Nevada Corporation (SNC) will join them in the future.
NASA initiated the companion commercial crew program in FY2011 with the expectation that the systems would be operational by 2015. That date slipped to 2017 at least in part because Congress provided less funding than requested in the program's early years.  That eventually changed, however, and Congress provided full or almost full funding for FY2015 and FY2016.  The FY2017 budget has not been approved yet.  NASA is operating under a Continuing Resolution (CR) at its FY2016 level, which in the case of commercial crew is actually more than the request for FY2017. 
While NASA's share of the funding may not be an issue now, the date for both SpaceX and Boeing commercial crew flights already has slipped to 2018 and few would be surprised if flights are further delayed. 
In its most recent annual report, NASA's Aerospace Safety Advisory Panel (ASAP) concluded that "there is still much left to do from a technical perspective" for both companies' systems -- SpaceX's Crew Dragon and Boeing's CST-100 Starliner.  While it found that there is "no evidence that needed safety considerations are being sacrificed merely to maintain schedule" and praised NASA's "excellent certification process," it cited challenges facing each company.   SpaceX turbine blades were not among the issues addressed in the ASAP report.   For SpaceX, it focused on the company's "load and go" procedure under which SpaceX plans to fuel the Falcon 9 rocket just prior to launch when the crew is already aboard. 
That has never been done in the U.S. human spaceflight program before for safety reasons. The on-pad explosion of a SpaceX Falcon 9 rocket on September 1, 2016 while it was being fueled for a pre-launch test accentuated those concerns.  Its payload, an Israeli commercial communications satellite (AMOS-6), was destroyed in the accident.  SpaceX noted at the time that if a crew had been aboard, the Crew Dragon's emergency abort system would have carried the capsule away from the pad and the crew would have been safe.  Nevertheless, NASA's International Space Station Advisory Committee expressed alarm about SpaceX's plan in November 2016.  ASAP's January 2017 report echoed those concerns and "strongly" encouraged NASA "to scrutinize" SpaceX's  plan and ensure that any additional risks are worth the gains.
NASA is and will remain dependent on Russia to take astronauts to and fr om ISS and provide "lifeboat" services for the crews while they are aboard the ISS until the commercial crew systems are operational.   NASA has not been able to launch people into space since the space shuttle program was terminated in 2011.
[свернуть]
"Были когда-то и мы рысаками!!!"

Валерий Жилинский

#15849
ЦитироватьSalo пишет:
http://www.spacepolicyonline.com/news/wall-street-journal-draft-gao-report-finds-problems-with-spacex-turbine-blades#.WJQRrMpg8MA.twitter
ЦитироватьWall Street Journal: Draft GAO Report Finds Problems with SpaceX Turbine Blades
Marcia S. Smith
А вот это серьёзно, может потребоваться изменение конструкции турбонасоса. А это время.

Сергей

Пока информации не достаточно, что бы судить о степени опасности трещин на элементах ТНА, они вообще могут появляться после окончания рабочей стадии. Сообщения о трещинах уже были на этом форуме, однако аварий с ТНА не было до сих пор. Когда Маск дозреет и пригласит ученых-прикладников, ему посчитают, дадут рекомендации где и что изменить, а пока будет лечить методом тыка, каждому свое.

Валерий Жилинский

ЦитироватьСергей пишет:
Пока информации не достаточно, что бы судить о степени опасности трещин на элементах ТНА, они вообще могут появляться после окончания рабочей стадии. Сообщения о трещинах уже были на этом форуме, однако аварий с ТНА не было до сих пор. Когда Маск дозреет и пригласит ученых-прикладников, ему посчитают, дадут рекомендации где и что изменить, а пока будет лечить методом тыка, каждому свое.
Согласен с тем, что, вероятно, эти трещины не опасны для одноразовых ракет.
   
Маск давно "созрел и пригласил", но ТНА космических ракет по умолчанию одноразовый.  учёных-прикладников тоже есть свои наработки, вот они и дали Маску параметры, по которым был рассчитан ТНА. Это вовсе не "метод тыка", это метод последовательного приближения, и судя по достигнутым результатам Маска использование этого метода себя оправдывает.

Not

ЦитироватьСергей пишет:
Когда Маск дозреет и пригласит ученых-прикладников
и журналистов-международников. Ржу я с этих литераторов  :D

Сергей

ЦитироватьВалерий Жилинский пишет:
Маск давно "созрел и пригласил", но ТНА космических ракет по умолчанию одноразовый.учёных-прикладников тоже есть свои наработки, вот они и дали Маску параметры, по которым был рассчитан ТНА. Это вовсе не "метод тыка", это метод последовательного приближения, и судя по достигнутым результатам Маска использование этого метода себя оправдывает.
Я так понимаю, это ваше мнение "созрел.. дали параметры..", Маск официально об этом не заявил бы.
Да и ученые - прикладники бывают разные, разные программные комплексы,разные модели термоупругопластичности и малоцикловой прочности, соответственно и разные конечные результаты. Судя по наличию трещин точность расчетной модели не достаточна.

Apollo13

http://uk.reuters.com/article/us-space-spacex-idUKKBN15H307

 
ЦитироватьSpaceX says fix underway for rocket turbine wheel cracking

SpaceX's final version of the Falcon 9 rocket, which Elon Musk aims to launch before the end of the year, will fix a potential problem with cracks in its turbopumps, the company said on Thursday. Its statement followed a report that the U.S. Government Accountability Office will flag turbine wheel cracks in the rocket's turbopumps as a safety issue. NASA, the U.S. space agency, and the Air Force are among SpaceX's customers.

The GAO's preliminary findings were reported by the Wall Street Journal on Thursday.

In an email to Reuters, SpaceX said it has "qualified our engines to be robust to turbine wheel cracks. However, we are modifying the design to avoid them altogether," said spokesman John Taylor.

In addition to flying cargo to the International Space Station, SpaceX has NASA contracts to begin flying astronauts to the orbiting research laboratory as early as 2018.

"SpaceX has established a plan in partnership with NASA to qualify engines for manned spaceflight," Taylor said.

GAO investigators found that the Falcon 9 turbopumps, which are part of the system that delivers propellants to the engine, have blades that are prone to cracking, the newspaper said.

SpaceX last month resumed flights following a 4-1/2-month investigation into why a rocket blew up as it was being fueled for a routine pre-launch test in Florida.

The cause of the accident was traced to a burst canister of helium in the rocket's second stage liquid oxygen tank. It was unrelated to the issue with the rocket's turbopumps.

The accident was SpaceX's second since the Falcon 9 debuted in June 2010. The company's next launch is targeted for Feb. 14.

(Reporting by Irene Klotz; Editing by Dan Grebler)

LRV_75

#15855
Надо в любом случае смотреть как ТНА будут вести себя в реальных повторных полетах, а не только прожиги на земле.
Для одноразовых пусков надежность ТНА для Фалькон-9 имхо  можно сказать подтверждена экспериментальным путем (статистикой реальных запусков). По крайней мере для коммерческих непилотируемых запусков
Главное не наличие проблем, главное способность их решать.
У каждой ошибки есть Имя и Фамилия

Наперстянка

ЦитироватьЗловредный пишет: 
И ещё:
 https://forum.nasaspaceflight.com/index.php?topic=42218.msg1637941#msg1637941
Цитировать...........................

The crack-prone parts are considered a potentially major threat to rocket safety, the industry officials said, and may require redesign of what are commonly called the Falcon 9's turbopumps. The National Aeronautics and Space Administration, they said, has warned SpaceX that such cracks pose an unacceptable risk for manned flights.
.................................... .
Это что же получается, выходит у них лопатки для топлива совсем не металлические?

Apollo13

ЦитироватьНаперстянка пишет:
Это что же получается, выходит у них лопатки для топлива совсем не металлические?
Деревянные! :)

Alex_II

ЦитироватьLRV_75 пишет:
Для одноразовых пусков надежность ТНА для Фалькон-9 имхоможно сказать подтверждена экспериментальным путем (статистикой реальных запусков). По крайней мере для коммерческих непилотируемых запусков
А разве кто собирался пускать пилотируемые корабли на повторно используемых ступенях?  :o
И мы пошли за так, на четвертак, за ради бога
В обход и напролом и просто пылью по лучу...

Валерий Жилинский

ЦитироватьСергей пишет:
Я так понимаю, это ваше мнение "созрел.. дали параметры..", Маск официально об этом не заявил бы.
Да и ученые - прикладники бывают разные, разные программные комплексы,разные модели термоупругопластичности и малоцикловой прочности, соответственно и разные конечные результаты. Судя по наличию трещин точность расчетной модели не достаточна.
Согласен во всём, кроме самого главного. В обычной металлической турбине одноразовой ракеты такие трещины не желательны, но отчасти допустимы. Но Мерлин сейчас испытывается и на ресурс для нескольких полётов, а металлические турбины с трещинами такого не выдержат - трещины будут расти. Значит мы чего-то не знаем, например, колесо может быть из композитов и растрескавшийся верний слой не влияет на прочность.
   
В общем. мы чего-то не знаем. Но знаем главное - НАСА посчитало трщины недопустимыми, и Маск меняет конструкцию турбонасоса.