SpaceX Falcon 9

[Плейшнер]

Seerndv написал:
 

Плейшнер написал:
 Слетало примерно 850 двигателей. 1 отказ
Если бы на Фалконе было не 9 двигателей а всего 1, то скорее  всего  никакого отказа  ЕЩЕ НЕ СЛУЧИЛОСЬ БЫ ВООБЩЕ.

- тогда это был бы монструозный двигун типа  "Бриаллиантовый хер им. Глушко" (С).
И статистика была бы   а-ля "Зенит"

 

Влияет вероятность отказа двигателя а не его размер.

[Плейшнер]

vlad7308 написал:
 

Плейшнер написал:
 

Сеерндв  написал:
Таки, как не ругай Маска за риск, но одну фразу надо написать ( а может вырубить на лбах фюреров &qуот;энергетиков&qуот; и &qуот;энергомашевцев&qуот;)    

Yeah. There was also an early engine shutdown on ascent, but it didn't affect orbit insertion.
 Shows value of having 9 engines!
Thorough investigation needed before next mission.
  https://twitter.com/elonmusk/status/1240262636547100672  

Слетало примерно 850 двигателей. 1 отказ
Если бы на Фалконе было не 9 двигателей а всего 1, то скорее  всего  никакого отказа  ЕЩЕ НЕ СЛУЧИЛОСЬ БЫ ВООБЩЕ.

рассуждение верно для учебника по теорверу. Про сферический двигатель в вакууме.

Просто иногда резервирование подается как нечто серьезно повышающее общую надежность.
Однако для десятидвигательных ДУ с ЖРД, резервирование только возвращает надежность системы к надежности единичного двигателя.
Без такого резервирования, надежность десятидвигательной ДУ провалиться

[vlad7308]

Эти рассуждения имели бы какой-то смысл, если была бы точно известна реальная (не бумажная) надежность. Она могла бы быть известной, если бы была нормальная статистика. Нормальная статистика - это сотни отказов и десятки-сотни тысяч пусков. Поскольку такой статистики нет и не предвидится, Вы берете цифры из справочника про сферические двигатели в вакууме. Что в реальности может дать ошибку на порядок. А у Вас рассуждения и расчеты вероятности основаны на третьей цифре после запятой. Разумеется, это лучше чем совсем ничего. Но не надо забывать, что это НЕ реальность.

ЗЫ либо! Речь идет именно о резервировании - то есть использовании двух или более одинаковых устройств (в данном случае двигателей). Причем избыточном.

[Плейшнер]

vlad7308 написал:
Эти рассуждения имели бы какой-то смысл, если была бы точно известна реальная (не бумажная) надежность. Она могла бы быть известной, если бы была нормальная статистика. Нормальная статистика - это сотни отказов и десятки-сотни тысяч пусков. Поскольку такой статистики нет и не предвидится, Вы берете цифры из справочника про сферические двигатели в вакууме. Что в реальности может дать ошибку на порядок. А у Вас рассуждения и расчеты вероятности основаны на третьей цифре после запятой. Разумеется, это лучше чем совсем ничего. Но не надо забывать, что это НЕ реальность.

ЗЫ либо! Речь идет именно о резервировании - то есть использовании двух или более одинаковых устройств (в данном случае двигателей). Причем избыточном.

Если бы была статистика сотен тысяч пусков, не о чем было бы разговаривать.
Речь как раз о том что приходится экстраполировать, тут теория лучшее

[vlad7308]

Главное не забывать, что это теория. И очень грубая и ненадежная.

[Apollo13]

Плейшнер написал:
 

Apollo13 написал:
Или так. Если первый отказ случился в 4 пуске, то при одном двигателе он "скорее всего" случился бы в 36-м. То есть CRS-11 в 2017-м.

Не так. При одном двигателе отказ случился бы 1 раз на 400 пусков (это если принять 2 отказа на 850 дв )
Т.е скорее всего еще не случился бы

Но ведь в реальности он случился на 36-м двигателе. И дело здесь скорее всего не в "невезении", а в том что первые двигатели были просто менее надежны, чем более поздние (по разным причинам). И это бы не изменилось, если бы двигатель был в 9 раз мощнее. Скорее наоборот более мощный двигатель в начале был бы еще менее надежен.

[Seerndv]

Apollo13 написал:
Но ведь в реальности он случился на 36-м двигателе. И дело здесь скорее всего не в "невезении", а в том что первые двигатели были просто менее надежны, чем более поздние (по разным причинам). И это бы не изменилось, если бы двигатель был в 9 раз мощнее. Скорее наоборот более мощный двигатель в начале был бы еще менее надежен.

Плейшнер написал:
Влияет вероятность отказа двигателя а не его размер.

[Apollo13]

Влияют время и деньги потраченные на создание двигателя. Больший двигатель разрабатывать дольше и дороже. Поэтому при тех же затратах на разработку он был бы менее надёжен.

[Not]

Apollo13 написал:
Влияют время и деньги потраченные на создание двигателя. Больший двигатель разрабатывать дольше и дороже. Поэтому при тех же затратах на разработку он был бы менее надёжен.

При тех же затратах на разработку его бы не было.

[Сергей]

Not написал:
 

Apollo13 написал:
Влияют время и деньги потраченные на создание двигателя. Больший двигатель разрабатывать дольше и дороже. Поэтому при тех же затратах на разработку он был бы менее надёжен.

При тех же затратах на разработку его бы не было.

Это сто пудов. Но хуже даже другое - большой мог и не получиться. То есть деньги, время потрачены, а движка нет. 

[tnt22]

https://spaceflightnow.com/2020/03/25/nasa-u-s-military-participate-in-probe-into-spacex-engine-malfunction/

NASA, U.S. military reviewing SpaceX engine malfunction
March 25, 2020 | Stephen Clark


Nine Merlin 1D engines arranged in an "octaweb" configuration on the Falcon 9 rocket's first stage. Credit: SpaceX

NASA and U.S. military officials are reviewing a malfunction that triggered a premature engine shutdown during a flight of a SpaceX Falcon 9 rocket earlier this month, a cautionary step before upcoming launches with a GPS navigation satellite and astronauts on SpaceX's Crew Dragon spacecraft.

A NASA spokesperson said Tuesday that SpaceX requested participation in the engine investigation from the agency's Commercial Crew Program and Launch Services Program. SpaceX is leading the inquiry, but representatives from both NASA programs will join the investigation.

One of nine first stage Merlin 1D engines shut down prematurely during a Falcon 9 launch March 18 from Cape Canaveral. The launcher overcame the engine malfunction by firing its other engines a little longer, and the Falcon 9 was able to deploy 60 satellites for SpaceX's Starlink Internet network into the mission's targeted orbit.

Elon Musk, SpaceX's founder and CEO, tweeted after the launch that the company would conduct a "thorough investigation" of the engine malfunction before the next Falcon 9 launch.

The in-flight engine failure on the March 18 launch marked the second time a Merlin engine has prematurely shut down on a Falcon 9 flight.

In October 2012, a Merlin 1C engine — a predecessor to the Merlin 1D — failed during the launch of a Dragon supply ship on the way to the International Space Station. The Falcon 9 was still able to deliver the Dragon spacecraft into orbit, but the failure resulted in the loss of an Orbcomm data relay satellite riding as a secondary payload.

SpaceX has reported no other in-flight Merlin engine failures in hundreds of engine flights. Falcon 9 rockets are designed to reach orbit even if it loses an engine during ascent, making it unique among active launchers.

The Falcon 9's first stage booster also missed a landing on SpaceX's offshore drone ship after the March 18 launch. SpaceX has not confirmed if the landing mishap was related to the engine outage during ascent.

"SpaceX is including ... (NASA) representatives in its investigation into the March 18 engine anomaly," said Josh Finch, a NASA spokesperson, in a written statement.

NASA awarded SpaceX a $2.6 billion contract in 2014 to develop, test and fly the Crew Dragon spacecraft, a human-rated capsule designed to ferry astronauts to and from the International Space Station. Boeing has a similar contract with NASA for its CST-100 Starliner spacecraft.

Finch said SpaceX is required to "available to NASA all data and resulting reports" under the terms of the the commercial crew contract.

"SpaceX, with NASA's concurrence, would need to implement any corrective actions found during the investigation related to its commercial crew work prior to its flight test with astronauts to the International Space Station," Finch said. "NASA and SpaceX are holding the current mid-to-late May launch timeframe, and would adjust the date based on review of the data, if appropriate."


A SpaceX Falcon 9 rocket climbed into space from Cape Canaveral on March 18 with 60 Starlink Internet satellites. Credit: SpaceX

Officials from the U.S. Space Force, meanwhile, are also "engaged" with SpaceX during the company's probe of the premature engine shutdown, according to Col. Robert Bongiovi, head of the launch enterprise division at the Space and Missile Systems Center.

SpaceX's next launch with a U.S. military payload is scheduled for April 29, when a Falcon 9 is set to loft a GPS navigation satellite into space from Cape Canaveral.

"I will say that for every one of our national security space launches, we review any issues or anomalies from a fleet-wide perspective," he said Tuesday. "So we are closely engaged with SpaceX on what transpired on that launch, and working to understand it to make sure that when we put a national security satellite on top of a launch vehicle that it will achieve orbit."

Bongiovi said such inquiries are a normal course of business for the military's oversight of national security launch contractors.

SpaceX and United Launch Alliance are the military's two incumbent national security space launch providers certified to carry the Defense Department's highest-priority — and most expensive — satellites into orbit.

"We do that with all providers," he said. Military officials regularly assess "test discoveries" and other data from launch providers.

"That's not a different process," Bongiovi said. "It's just another set of data that we're working with to get to that (GPS) launch."

He said the GPS launch remains on schedule for late April for now, but the teams are approaching a decision on whether to fuel the spacecraft, which is inside a clean room at an Astrotech payload processing facility in Titusville, Florida, near the launch pad at Cape Canaveral Air Force Station.

"The satellite is about to fuel, and that's a major decision point," Bongiovi said. "So I think it's prudent on our part to be looking at the situation and whether we want to proceed, and that's what we're doing. But today it remains on schedule for the end of April."

He said the engine issue is "treated like we treat every other issue on every other flight" conducted by SpaceX or ULA.

"We make sure we understand what happened and whether that's an issue that needs to be resolved, or something we proceed with," Bongiovi said.

The coronavirus pandemic is another factor military teams may consider when they decide whether to move forward with the GPS launch in late April.

Officials from the 45th Space Wing, the military unit that operates the launch range at Cape Canaveral, say they plan to keep the base open for launches.

Brig. Gen. Doug Schiess, the wing commander, said earlier this week that he has reduced staff on range operations teams to just essential personnel. Range teams are practicing social distancing techniques and working on alternating launches to minimize their risk of exposure to the COVID-19 viral disease, and public launch viewing sites have been closed for the planned launch of a United Launch Alliance Atlas 5 rocket Thursday.

But the range team is just one segment of a broader group of employees from contractors, launch providers and satellite technicians required for a launch, some of whom need to travel from other states and countries.

For example, the Lockheed Martin-built GPS satellite was built at a facility in Colorado, and teams there have traveled to Florida to help prepare the spacecraft for launch.

SpaceX's next launch from Cape Canaveral had been scheduled for March 30 with Argentina's SAOCOM 1B radar observation satellite. But Argentine officials have postponed due the coronavirus pandemic. Among other concerns, Argentine personnel needed to support the launch were unable to travel to Florida.

[Искандер]

Elon Musk touts low cost to insure SpaceX rockets as edge over competitors

The price tag for a Falcon 9 launch can vary greatly depending on what a customer demands. In recent military launch contracts, the Air Force awarded SpaceX about $95 million per launch – as the national security nature of the missions come with additional requirements for the company. But, when SpaceX re-uses parts of its rocket, the company says it can charge even less than its list price. In a briefing earlier this year, SpaceX director of vehicle integration Christopher Couluris said the company can "bring launches down to below $30 million per launch."


"[The rocket] costs $28 million to launch it, that's with everything," Couluris said, adding that reusing the rockets is what is "bringing the price down."

[Seerndv]

https://aviationweek.com/special-topics/sustainability/economics-rocket-reuse-still-air
Economics Of Rocket Reuse Still Up In The Air
Irene Klotz April 17, 2020


Blue Origin is developing the BE-4 engine, which it will install on its reusable New Glenn rockets and sell to United Launch Alliance (ULA) for its onetime-use Vulcan booster. ULA plans to eventually reuse just the engines.
Credit: Blue Origin

Print Headline: Price of Reusability

The first Falcon 9 rocket to land successfully after dispatching a payload into orbit stands on permanent display outside SpaceX headquarters in Hawthorne, California, a testament to the perseverance of founder, CEO and chief engineer Elon Musk, who wants a fleet of fully reusable spaceships to reduce the cost of colonizing Mars.

The vision is shared by fellow tech entrepreneur Jeff Bezos, whose Kent, Washington-based Blue Origin space company is developing a series of reusable vehicles, beginning with the New Shepard suborbital passenger transport system. The New Shepard made 12 uncrewed flight tests over the last five years, with more to come before commercial flights begin.

Bezos also has pumped $2.5 billion into developing the New Glenn, a reusable system powered by seven BE-4 methane-fueled engines designed to carry nearly 50 tons to low Earth orbit. "That is the smallest orbital vehicle we are planning to build and launch," says Clay Mowry, Blue Origin vice president of sales, marketing and customer experience.

Falcons unlikely to fly more than 10 times
ULA, Rocket Lab mull partial reuse
But the first BE-4s to power a rocket to orbit may not be aboard the New Glenn. United Launch Alliance (ULA) is buying the engines to power the first stage of its Vulcan rocket, an expendable booster—at least for now—which, like the New Glenn, is slated to debut next year.

At some point, ULA may decide to recover and reuse just the BE-4 engines, a pair of which will fly on each Vulcan. The idea is for the engine compartment to disengage after launch and fall back through the atmosphere protected by an inflatable hypersonic shield. A helicopter would be positioned to snag the engine section midair as it makes a parachute descent. ULA calls the approach its Sensible Modular Autonomous Return Technology, or SMART.

"It does not impact, in any significant way, the overall performance of the launch vehicle because you don't have to save fuel to fly home with," ULA CEO Tory Bruno tells Aviation Week. "You still get to burn up all your fuel, separate your engine, which is the most expensive piece, and recover it."

"We have not really changed our assessment over the last couple of years because we have yet to see the other forms of reusability—flyback or propulsive return to Earth—demonstrate economic sustainability on a recurring basis," Bruno says. "It's pretty darn hard to make that actually save money. . . . We've seen nothing yet that changes our analysis on that."


A SpaceX Falcon 9, which landed on a drone ship positioned in the Atlantic Ocean, returned to Port Canaveral, Florida, on Dec. 7, 2019, after delivering a Dragon Cargo ship into orbit for NASA. Credit: SpaceX
SpaceX currently is the only launch company reflying orbital rockets. SpaceX launched its final version of the workhorse Falcon 9 booster, called the Block 5, in May 2018. Within two months, the company was flying Block 5s exclusively. The upgrade includes higher-thrust Merlin engines, stronger landing legs and dozens of upgrades to streamline recovery and reuse.

Block 5s were designed to fly 10 times with minimal maintenance between flights, and up to 100 times with refurbishment. SpaceX President and Chief Operating Officer Gwynne Shotwell says the company no longer expects to need to fly a Falcon 9 more than 10 times.

"We don't have to ramp up our production, at least for boost phases, like we thought we were going to," Shotwell said on March 10 at the Satellite 2020 conference in Washington.

"Fr om a reliability perspective, we want to know the limits of Falcon 9, so we'll push them, but . . . some government customers want new vehicles—I think over time, they will come to flight-proven vehicles as well," she added. "But if I have to build a couple of new ones every year, or 10 new ones a year, that adds to the fleet, and I don't know that I'll have to push a rocket more than 10 [flights.]"

With regard to how much the company has been able to cut costs by reflying rockets, Shotwell would only say, "We save a lot of money."

As a privately held company, those operating expenses are not publicly available, but the Block 5 flight record is. So far, SpaceX has flown 14 Block 5 core boosters over 31 missions, including two Falcon Heavy flights, which use three cores apiece.

Rocket Lab is testing to see if it can reuse its Electron small-satellite launch vehicle. Credit: Rocket Lab
Of those 14 boosters with flight history, five remain part of the operational fleet. The rest were expended—several after multiple missions—due to payload performance requirements or unsuccessful landings. One booster was intentionally destroyed as part of a Crew Dragon capsule launch abort flight test.

SpaceX's fleet leader flew five times before failing to land on a drone ship stationed off the Florida coast on March 18. SpaceX has not said if the botched landing was related to a premature engine shutdown during the final phases of ascent. The rocket's remaining eight Merlin engines compensated for the shutdown, and the payload—a batch of 60 SpaceX Starlink broadband satellites—reached its intended orbit.

While it continues to fly the Falcon 9 and Falcon Heavy for NASA, national security and commercial missions, SpaceX is developing a fully reusable, human-class deep-space transportation system called Starship at its own expense.

Another company testing the waters of reusability is Rocket Lab, which builds and flies the Electron small-satellite launcher.

"For a long time, I said we weren't going to do reusability," Rocket Lab CEO Peter Beck said in August 2019, when he announced the new initiative. "This is one of those occasions wh ere I have to eat my hat."

Electrons do not have the performance for a propulsive return like SpaceX's Falcons do, so Rocket Lab is pursuing a midair, helicopter recovery system to snare the booster's first stage. The intent is not to reduce costs per se but to increase flight rates without having to boost production. The company currently is producing one Electron rocket about every 30 days. "We need to get that down to one a week," Beck says.

"We view [rocket reuse] as sort of a journey," ULA's Bruno adds. "We're going to start with the engines because we're pretty sure we can save money with that and pass those savings on right away. As we learn more by doing, we'll continue to assess other valuable parts of the rocket, and we may discover that we can do that there as well."

"There is one funny thing about reusability," he adds. "As you make your rocket less expensive, and you make parts of your rocket less expensive, it's harder to close a business case on reuse because the thing you're recovering isn't as valuable. There's a balance there."

[triage]

https://www.cnbc.com/2020/04/16/elon-musk-spacex-falcon-9-rocket-over-a-million-dollars-less-to-insure.html

Elon Musk touts low cost to insure SpaceX rockets as edge over competitors

PUBLISHED THU, APR 16 202011:52 AM
Michael Sheetz@THESHEETZTWEETZ

SpaceX is launching more often than any other country or company and CEO Elon Musk touted low insurance costs as proof of the improving reliability of his company's Falcon 9 rockets.

"Last I checked, over a million dollars less ... to insure a Falcon 9 mission," Musk said in tweets Wednesday evening.

Insurance on a launch is "the acid test" for the reliability of a rocket, Musk added in another tweet. A top space insurance underwriter, speaking on condition of anonymity, told CNBC that Musk's reference is true for insurance premiums, which are based on the rocket's price tag, but not for the insurance rate, which is based on the market's perceived reliability of the rocket.

SpaceX advertises Falcon 9 rocket launches on its website with a $62 million price tag. The insurance rate on a Falcon 9 is about 4% currently, the underwriter said. That's the same rate as competitors' similarly-capable rockets, such as the European launcher Arianespace's Ariane 5 or U.S. rocket builder United Launch Alliance's (ULA) Atlas V. But Ariane 5 and Atlas V launches go for upwards of $165 million each, meaning a Falcon 9 premium is about $2.5 million while its competitors' premiums would be in the range of $7 million.

In essence, the underwriter said a Falcon 9 mission is cheaper to insure because the rocket costs less than competitors' – not necessarily because it is seen as more reliable. The underwriter added that Musk's method of comparing insurance premiums is additionally misleading given that launch insurance is almost always based on more than just the cost of a rocket itself. A launch insurance policy typically includes the cost of the launch vehicle, the price of the spacecraft it's launching and the amount paid for the insurance, the underwriter explained.
...
The price tag for a Falcon 9 launch can vary greatly depending on what a customer demands. In recent military launch contracts, the Air Force awarded SpaceX about $95 million per launch – as the national security nature of the missions come with additional requirements for the company. But, when SpaceX re-uses parts of its rocket, the company says it can charge even less than its list price. In a briefing earlier this year, SpaceX director of vehicle integration Christopher Couluris said the company can "bring launches down to below $30 million per launch."

″[The rocket] costs $28 million to launch it, that's with everything," Couluris said, adding that reusing the rockets is what is "bringing the price down."
....
SpaceX has been able to recover two major pieces of its rockets: The large "first stage" boosters and the rocket's nosecone (also known as its "fairing"). The boosters, which SpaceX has often landed, make up about 60% of the total cost of the rocket, or about $37 million. SpaceX has also been able to recover the fairings – which make up about 10% of the total cost, or about $6 million – by either fishing them out of the ocean or catching them in large nets strung up behind boats.
...

[cross-track]

triage написал:
 

https://www.cnbc.com/2020/04/16/elon-musk-spacex-falcon-9-rocket-over-a-million-dollars-less-to-insure.html

″[The rocket] costs $28 million to launch it, that's with everything," Couluris said, adding that reusing the rockets is what is "bringing the price down."

[Seerndv]

- да уж, Батуту Зубдаевичу (С) придётся жо на британский флаг рвать чтоб достичь хоть где-нибудь :

triage написал:
 In a briefing earlier this year, SpaceX director of vehicle integration Christopher Couluris said the company can "bring launches down to below $30 million per launch."

[triage]

Однако - просто там попалось, приводить оригинал 2017 не хочется т.к. устарело

https://www.facebook.com/photo.php?fbid=2959528344109140
Сопов Сергей
14 апреля в 13:04

откуда реальные показатели? Это публикация 2017 года и автор сам сообщает, что опирается на предположения: https://www.astronews.space/.../252-raschet-stoimosti...

24,9+ страховка+... можно и 28 получить

[Not]

triage написал:
  In a briefing earlier this year, SpaceX director of vehicle integration Christopher Couluris said the company can "bring launches down to below $30 million per launch. "

Эти замечательные предсказания были сделаны до того как утопили после четвертого полета, или таки до?

[Not]

То есть я понимаю, что некий марсоколонизатор обещал повторный пуск через два часа после посадки, значит тогда будет по 28?

[Alex_II]

Not написал:
Эти замечательные предсказания были сделаны до того как утопили после четвертого полета,

После ПЯТОГО полета, дешевый брехунок, после пятого...