Author Topic: Aerojet Rocketdyne's proposed RD-180 replacement - the AR-1 (aka AJ-1E6)  (Read 105533 times)

Offline Jim

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For an EELV engine, the AR-1 will have to fly enough times to prove its reliability. The Atlas V will have to be redesigned, and flown a number of times to prove the reliability of the redesigned Atlas.

Not necessarily true

Offline Sean Lynch

For an EELV engine, the AR-1 will have to fly enough times to prove its reliability. The Atlas V will have to be redesigned, and flown a number of times to prove the reliability of the redesigned Atlas.

Not necessarily true
ULA is currently seeking designs. (So, we can't assume AR-1 is given.)
It would seem logical to me that if I were going to go to the trouble of designing a new engine to replace a current design I'd be shooting for a bolt in replacement for my proven work horse -as much as possible.
Atlas V is a fine bird, and well understood. Jim may have said something like this if he had time...and I'd agree with him! :)
« Last Edit: 06/27/2014 01:57 PM by Sean Lynch »
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Offline edkyle99

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For an SLS booster, the Merlin 1D will win on cost ....
Impractical, and probably not less costly.  SLS would need 30 Merlin 1D engines (15 per booster) at least.  How many scrubs per launch?

Even SpaceX is working on a higher thrust engine.

Quote
The Atlas V will have to be redesigned, and flown a number of times to prove the reliability of the redesigned Atlas. The Delta IV is proven, why bother with a new and untested rocket?
First, Centaur.  Second, if the new engine is properly specified, the Atlas design won't change substantially.  Third, Delta 4 is the world's most expensive rocket.  Fourth, Delta 4 doesn't cover the entire EELV payload range as well as Atlas 5, which can lift heavier "Medium" payloads with a single core.

 - Ed Kyle
« Last Edit: 06/27/2014 02:26 PM by edkyle99 »

Offline Lobo

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For an EELV engine, the AR-1 will have to fly enough times to prove its reliability. The Atlas V will have to be redesigned, and flown a number of times to prove the reliability of the redesigned Atlas.

Not necessarily true
ULA is currently seeking designs. (So, we can't assume AR-1 is given.)
It would seem logical to me that if I were going to go to the trouble of designing a new engine to replace a current design I'd be shooting for a bolt in replacement for my proven work horse -as much as possible.
Atlas V is a fine bird, and well understood. Jim may have said something like this if he had time...and I'd agree with him! :)

@this.  AJR already has specifcations on the RD-180, so they'd know exactly all of it's mounting points of contact with the Atlas MPS.  And they'd just design AR-1 to interface with that.  Or I imagine they could essentially design an adaptor that the two AR-1's woudl mount to, that woudl adapt them to the Atlas MPS, including spliting what I imagine are just one LOX line and one RP-1 line into two lines to feed the two AR-1 turbo pumps.   In fact such an adaptor would make more sense, because AJR could design the AR-1 to be a drop in fit for the AJ26's on Antares (which is what they'll basically be anyway) and they could be used on Antares too. 
With an adaptor that AJR develops, that means Atlas itself won't have to change much, if at all. 

AJR also could make two different versions of hte AR-1.  They'd essentially be the same engine, just one tailored to interface with the Atlas boat tail and one tailored to intereface with the Antares boat tail.



Offline baldusi

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AJAtlas V already have such abstraction on its Propulsion Module. And Antares also has a propulasion module adapter thaat mounts and handles the two AJ-26 as a single unit. Main issue would probably be fluids and start up GSE.

Offline HarryM

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What's trickier, getting the replacement to fit, or getting it to have the same mixture ratio (so as not to have to resize tanks)?

Online TrevorMonty

Has anybody read this Aviation Week article? I don't have subscription.

What interested me was ULA's take on reusability are they allowing for recovery of booster as part of a new engine development.

 http://m.aviationweek.com/awin-only/ula-looking-reusability-3d-printing-rd-180-replacement

There is alot of criticism of ULA lack of innovation. From what I've read they would like to do more but are limited by their charter and parent companies. Plus there is their reliability record "If it's ain't broke don't fix it."

With SpaceX threatening their market share hopefully they will be given more freedom to innovate.



Online Space Ghost 1962

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Online TrevorMonty

Thanks Space Ghost for the links.

I doubt RD 180 recovery method would be economical. To be competitive ULA will need to recover the complete booster.

Offline edkyle99

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Thanks Space Ghost for the links.
I doubt RD 180 recovery method would be economical. To be competitive ULA will need to recover the complete booster.
Not just recovery itself, but also affordable refurbishment/checkout/turnaround while ensuring the current high rate of success.

As for the competition (which actually doesn't have enough rocket to handle all Atlas 5 missions yet), it has been having a long spring and summer trying to launch one brand new rocket.  Imagine if it were trying to launch a previously flown, reentered rocket.

 - Ed Kyle
« Last Edit: 07/07/2014 03:51 AM by edkyle99 »

Online TrevorMonty

If ULA do decide to do a reusable booster they should benefit from DARPA XS1 program. ULA a willing to buy external expertise.

Offline Prober

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Try here:
http://ula.lonebuffalo.com/story.cfm?story_id=7426059

As for recovery:
http://www.ulalaunch.com/uploads/docs/Published_Papers/Evolution/EELVPartialReusable2010.pdf

Gass says innovations maturing now make a new propulsion system more realistic than even a couple of years ago. "We view the reach and the cost to be not as great as it was a couple of years ago," Gass said told reporters during a June 18 roundtable. "It is not only … fuel sources [or] reusability, but I would also [like] to emphasize taking advantage of today’s manufacturing techniques" such as 3D printing.

this could be a very exciting time for engine manufacturing and development.   

2017 - Everything Old is New Again.
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Offline simonbp

As for the competition (which actually doesn't have enough rocket to handle all Atlas 5 missions yet), it has been having a long spring and summer trying to launch one brand new rocket.  Imagine if it were trying to launch a previously flown, reentered rocket.

Very true right now. But probably not still going to be true five years from now, or whenever an AR-1 Atlas flies for the first time.

ULA is in a really bad position right now. They could just keep flying Atlas as-is, but even if the RD-180s keep flowing, that risks incurring the wrath of politicians. To design an entirely new vehicle would take a huge amount of effort, and would undercut their main selling point of flight experience. Putting a new US engine on Atlas is the least risky strategy, but still risks being overtaken by events if it takes >5 years to get flightworthy.

A mitigation strategy might be to make some other modifications to the Atlas production line in parallel to the new engine/thrust structure that would allow ULA to have an optional path to a recoverable first stage. Much like how the first few F9 v1.1 flights had the structural hardpoints for legs, but no actual legs. That would allow ULA to compete with SpaceX on their own terms, without a massive redesign or abandoning "heritage".

Offline USFdon

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What I'm assuming is a recent update to Aerojet Rocketdyne's website.

Quote
AR1 Booster Engine
Leveraging more than $300 million invested in rocket engine development over the last two decades, the Aerojet Rocketdyne AR1 incorporates the latest advances in rocket engine technology, materials science and modern manufacturing techniques to deliver an affordable and reliable booster engine to meet current and future U.S. space launch needs.

Having an American-designed and built booster engine in production would enable the U.S. to end its current dependence on foreign engine suppliers to launch some of its most important national security, civil and NASA payloads to orbit.

Using an advanced oxidizer-rich staged combustion engine cycle, the liquid oxygen/kerosene AR1 will generate 500,000 lbf of thrust at sea level. The thrust class enables the engine to be easily configured for use on multiple launch vehicles, including the Atlas V and the Advanced Boosters being considered for NASA’s Space Launch System.

The AR1 also will be an affordable propulsion solution, enabling U.S. launch vehicle providers to be more competitive in the world marketplace. Low production costs will be realized by incorporating the latest manufacturing technologies such as additive manufacturing (3D printing), white light inspection and low-cost brazing and forming – all of which have recently been proven on other Aerojet Rocketdyne rocket engine programs.

Aerojet Rocketdyne is the industry leader in building liquid-propellant rocket engines and is well positioned to bring this engine to market quickly and affordably. With more than 60 years of experience in the space launch industry, Aerojet Rocketdyne has built and launched thousands of rocket engines with unparalleled reliability. This remarkable track record, along with our outstanding engineering workforce, gives the nation confidence that a flight-ready AR1 rocket engine can be qualified approximately four years after program inception.

AR1 at a Glance

All-American design and production
Advanced oxygen-rich staged combustion kerosene technology
500,000 lbf thrust (sea level)
Propellants: Liquid-oxygen (Lox)/Kerosene (RP-1)
Configured to accommodate multiple applications
Fast-paced and affordable development
Advanced low-cost manufacturing techniques

http://www.rocket.com/ar1-booster-engine

It's nice to see pictures of the proposed engine(s). Let's hope that there is some movement on this in the next couple of months.


Offline simonbp

Well, that looks familiar. Though, I'm sure they have a really good marketing reason for not calling it LR87-AR-1.

No word on Isp, though.

Offline Lobo

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Interesting.

The double configuration is obviously a good move, as there's not really a potential customer for just one engine.  I wonder if it would have a common turbo pump making it a single, dual-chamber engine?  Or still two individual engines, just in a duplex mount?

Offline russianhalo117

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Interesting.

The double configuration is obviously a good move, as there's not really a potential customer for just one engine.  I wonder if it would have a common turbo pump making it a single, dual-chamber engine?  Or still two individual engines, just in a duplex mount?
in the graphic there appear to be two turbo pumps (Black cylinder-like components) shown on each engine, 1 for RP-1 and 1 for LO2, so there are two separate AR-1 LREs mounted in a dual engine frame.
« Last Edit: 07/25/2014 01:39 AM by russianhalo117 »

Offline sdsds

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In this context it seems fair to also post the alternate version of the image, even though it adds no technical content.
-- sdsds --

Offline anonymous

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Quote
AR1 at a Glance

All-American design and production
Advanced oxygen-rich staged combustion kerosene technology
500,000 lbf thrust (sea level)
Propellants: Liquid-oxygen (Lox)/Kerosene (RP-1)
Configured to accommodate multiple applications
Fast-paced and affordable development
Advanced low-cost manufacturing techniques

I love the description of the AR1 as an "All-American design". It's an All-American design about the same way "My Country, 'Tis of Thee" is an All-American patriotic song. Still, the Russians copied the Space Shuttle and Concorde during the Cold War, so perhaps it's karma.

Offline Steven Pietrobon

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Here's a presentation from July 2013 showing how the dual chamber AJ1E6 would have look like on Atlas.

"Common engine solution for SLS, Atlas V, & Antares"

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140002714.pdf
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

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