标题: US Can Not Live Without Russian Rocket Engines for Another Decade [打印本页] 作者: choi 时间: 9-6-2017 17:01 标题: US Can Not Live Without Russian Rocket Engines for Another Decade 本帖最后由 choi 于 9-6-2017 18:35 编辑
Andy Pasztor, US Grapples with Launchpad Delay; Pentagon switch from Russian-made rocket engines to domestic alternative takes longer than expected. Wall Street Journal, Sept 5, 2017. https://www.wsj.com/articles/pen ... -engines-1504526402
Quote:
(a) "Government and industry officials said United Launch Alliance, the Pentagon's primary rocket provider, likely will likely continue flying some 1990s-vintage Atlas V boosters [ie, first, lower stage] with Russian-built [RD-180] engines through 2024 or 2015.
"Other people familiar with the details said United Launch -- a joint venture between Lockheed Martin Corp and Boeing Co -- might have to extend the timeline as far out as 2018.
(b) "United Launch, Elon Musk's Space Exploration Technologies Corp, and commercial startup Blue Origin LLC -- founded and run by Amazon.com Inc Chief Executive Jeff Bezos -- are racing to develop their own versions of less-costly, more-capable rockets using only US-made engines. The outcome of that competition partly depends on how quickly United Launch is able to pivot away from the more expensive
(c) "Launches of Falcon 9 rockets built by SpaceX, as Mr Musk's company is called, start at $83 million for the military, more than 40% below traditional United Launch prices.
"The Boeing-Lockheed venture expects to have a new engine fully tested by 2019 and a replacement rocket, called Vulcan, certified to carry Pentagon payloads by 2022 or 2023. But * * * [more testings will be needed] until Vulcan demonstrates its dependability [that explains the 2024 in (a) above].
(d) "Developing and test flying such a powerful new engine historically has cost about $1 billion, with a price tag of roughly three times that much for an entirely new rocket and enhanced ground support system. * * * For United Launch, it isn't clear what portion of development costs the Pentagon ultimately will cover.
"SpaceX is four years late [due to 'structural issues raised by the number of engines': Musk] flying a bigger derivative of its current Falcon 9 rocket, called the Falcon Heavy, powered by 27 engines. The maiden launch is now scheduled for late 2017.
"Part of a Blue Origin rocket exploded on the ground earlier this year. Delaying a new, methane-fueled engine the company plans to use itself and hopes to sell United Launch.
(e) "The spokeswoman for the joint venture [United Launch] said it * * * has 'more than 30 [RD-180] engines' either on hand or in the pipeline from Russia. 作者: choi 时间: 9-6-2017 17:03
Note:
(a)
(i) The report is locked behind paywall.
(ii) The take-home lesson is that US is not good at everything.
(iii) There is no need to read the rest, which is not available for free anyway.
(b) RD-180 (RD is the two-letter acronym of two words in Russian for "Rocket Engine"/ table: Manufacturer NPO Energomash + thrust at vacuum and sea level are 4.15 MN and 3.83 MN, respectively, where MN = meganewton; mega = million) / "It features a dual combustion chamber, dual-nozzle design and is fueled by a kerosene/LOX mixture" (LOX = liquid oxygen) Wikipedia
(i) Wikipedia says its production is "1999-2014." It is plain wrong with regard to 2014. The engine remains in production, which is just the common sense. Otherwise where can Pentagon get new supply?
(ii) RD-180 first in use was in 2000.
(iii) meaning of manufacturer name:
Brian Harvey, Russia in Space; The failed frontier? Springer, 2001, at page 253 https://books.google.com/books?i ... rgomash&f=false
("NPO Energomash, its current name, or to be more precise, Energomash imemi Valentin Glushko (Energomash, dedicated to the memory of Valentin Glushko)" )
Russian full name and its English translation.
(iv)
(A) "Thrust is a reaction force described quantitatively by Isaac Newton's second and third laws. * * * Force, and thus thrust, is measured in the International System of Units (SI) as the newton (symbol: N), and represents the amount needed to accelerate 1 kilogram of mass at the rate of 1 meter per second per second." Wikipedia for "thrust"
(B) "Since they need no external material to form their jet, rocket engines can perform in a vacuum and thus can be used to propel spacecraft and ballistic missiles." Wikipedia for "rocket engine"
(c) "The first payload launched with an Atlas V was the Hot Bird 6 communications satellite launched from Cape Canaveral * * * into geostationary transfer orbit (GTO) on August 21, 2002." Wikipedia for "Atlas V"
(d)
(i) Falcon Heavy. SpaceX, undated http://www.spacex.com/falcon-heavy
(ii) Merlin Engines. SpaceX, undated www.spacex.com/news/2013/03/26/merlin-engines
("The Merlin engine that powers the first stage of Falcon 9 is developed and manufactured in-house by SpaceX. Burning liquid oxygen and rocket-grade kerosene propellant, a single Merlin engine emits 845 kilonewtons (190,000 pounds) of thrust at liftoff, rising to 914 kilonewtons (205,500 pounds) as it climbs out of Earth's atmosphere. Merlin's thrust-to-weight ratio exceeds 150, making the Merlin the most efficient booster engine ever built")