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A comment on Rocket Will Be Recaptured in Midair with a Helicopter.

Re:Rocket Will Be Recaptured in Midair with a Helicopter by ansible on Tuesday April 14, 2015 @07:43AM (#9373438)
It is an interesting approach by the ULA, but I have concerns.

From [1]:

Vulcan, slated for its maiden launch in 2019, will be powered by either a pair of exotic Blue Origin BE-4 liquefied natural gas main engines for 1.1 million pounds of thrust or two conventional Aerojet Rocketdyne AR-1 kerosene powerplants for a million pounds of thrust.

I'm also concerned about using fewer larger engines. While this can be more reliable (less moving parts means less chance of failure), it also means there is no engine-out capability to continue the mission. This also means a lower production volume, which means higher cost per engine, all other things being equal (which they aren't).

The word 'exotic' also gives me pause.

At any rate, it should be interesting. I hope they post testing videos!

[1] http://spaceflightnow.com/2015/04/13/ula-unveils-its-future-...

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Re:Rocket Will Be Recaptured in Midair with a Helicopter by JshWright on Tuesday April 14, 2015 @09:01AM (#9373842)
What do you mean by fewer? Vulcan is replacing the Atlas and Delta platforms. Both use a single engine per core (the Atlas uses the Russian RD-180, while Delta uses Aerojet's RS-68).

This will actually double the number of engines they're using.

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Re:Rocket Will Be Recaptured in Midair with a Helicopter by ansible on Tuesday April 14, 2015 @10:22AM (#9374434)
What do you mean by fewer?

1 or 2 vs. 9 for a Falcon9 core.

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Re:Rocket Will Be Recaptured in Midair with a Helicopter by JshWright on Tuesday April 14, 2015 @10:29AM (#9374499)
Falcon 9 is a SpaceX rocket, not a ULA rocket.

There are advantages and disadvantages to both approaches. ULA has a long track record of going to space very reliably on single engine platforms.

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Re:Rocket Will Be Recaptured in Midair with a Helicopter by ansible on Tuesday April 14, 2015 @01:23PM (#9375817)
Falcon 9 is a SpaceX rocket, not a ULA rocket.

Yes, I'm aware of that.

There are advantages and disadvantages to both approaches. ULA has a long track record of going to space very reliably on single engine platforms.

That's true. Both the Atlas and Delta programs have been pretty reliable.

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