Author Topic: Aerojet Rocketdyne's proposed RD-180 replacement - the AR-1 (aka AJ-1E6)  (Read 165796 times)

Offline butters

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I'm sure AJR will welcome them with open arms. Highly unlikely though, isn't?
Yup. Hence I qualified it with the word 'remote', as unlikely but not zero.


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The amount of money spent on something has no relationship to how long it should survive in the marketplace. And if the marketplace does move to reusable launchers, then engines that enable that are what AJR should really be focused on if they want to stay in the rocket supplier business.
Never actually said there is a relationship between the money spent on a system and its marketplace viability. However, AR-1 already is a reusable engine and the government have effectively paid for it. Since engines like this can take up to 7 years to develop at a cost of hundreds of millions, a new entrant to the RLV market could choose to avoid those costs by purchasing something commercial and off the shelf at its marginal cost instead of reinventing the wheel. They could then focus their limited resources on all other parts of the RLV and field it sooner than would be otherwise possible. Another company attempting to compete with Blue Origin and SpaceX in the RLV market could make themselves more competitive by exactly the money and time they did not spend on something!. I've no idea how likely this scenario is with the AR-1 in particular, but it's perfectly plausible.

If ULA would choose BE-4 over AR-1, then why would anyone else choose AR-1 over BE-4? Especially for an RLV, where methane has advantages over RP-1.

Offline Lars-J

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However, AR-1 already is a reusable engine

How is it already reusable? It's early in development, and re-usability has not been something that AJR has promoted as a part of AR-1 - unless I missed it.

and the government have effectively paid for it.

How so? It is nowhere near done, nor is the entire development funded.

Offline Space Ghost 1962

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One word: RL10

It will still be around five years from now.
It's not very likely but it might not survive either. Delta IV is already being discontinued and ULA could pick BE-3 for ACES. The remaining user is SLS which could also get cancelled.
Underestimates the fundamental effectiveness of the RL10.

It may fly in other ways for many decades. BTW Centaur advantages as well like this.

It might or it might not. But costs matter, now more than ever. It is only recently that the industry has broken out of the "isp at any cost" mentality - we even have GTO missions done with RP-1 stages (gasp!). Two new launch vehicles are being developed with MethaLox upper stages. None of them will have engines that match the isp of RL-10, but they could still kill it off.


Which is why ACES/distributed launch appears. As an on orbit, long duration, propulsion system, it may have a considerable life. "May" being very much the case.

AJR have been working on reducing RL10 build cost by redesign it to enable use of modern manufacturing technology.
In theory yes. There's talk, lets see about what flies. AJR hasn't sold a cheap US LRE ever. They might require high price still. I would be on them wanting too much margin in the sell, as that's what they've gotten used to doing since forever.

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I think it is still ULA preferred engine but having BE3U as option helps keep AJR on their toes.
ULA prefers one US, and one engine for that. BE3U may have cost and thrust, but to do ULA's missions as current they may need more than these.

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Its in AJR best interest to bring price down so ULA can stay competitive. Less ULA flys the less engines they buy.
AJR doesn't necessarily see this.

Likely it is an all or nothing thing. Either RL10 costs are affordable against rivals, or ULA builds in the costs of everything else they need to add to an alternative, which they can do.

And it works both ways here. Even if AJR has government contracts for engines for govt HSF vehicles, they also need commercial sales as well, otherwise they are funded too narrowly for them to do business well. They don't need to be losing certain contracts.

Perhaps its a game of "contract chicken"?

If ULA would choose BE-4 over AR-1, then why would anyone else choose AR-1 over BE-4? Especially for an RLV, where methane has advantages over RP-1.

Not necessarily in the case of SLS advanced booster. Congress seems to prefer expendables, so the increased energy density of kerolox would be an advantage.

(Although 4x F9R Block 5 (two apiece, not unlike how Zenit's worked to boost Energia) to me would be the best solution for SLS longest run of missions, but then I'm no political tool.)

Online Coastal Ron

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However, AR-1 already is a reusable engine and the government have effectively paid for it.

A rocket engine is only reusable if you can reuse it. That means it has to be recovered as part of a 1st stage, or by recovering the engine from the 1st stage before it lands in the water (ala Vulcan mid-air engine recovery). And that capability is not necessarily the responsibility of the engine, but of the rocket manufacturer.

Anyone being serious about getting into the launch business is going to survey the competition and see that the two to beat both make their own engines and rockets. So buying an engine that is not built to be used for a reusable rocket is not likely to be popular.

Maybe there is a government program that could use the AR-1, but it would be hard to see a scenario where a commercial rocket manufacturer would want to use the AR-1.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline Darkseraph

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If ULA would choose BE-4 over AR-1, then why would anyone else choose AR-1 over BE-4? Especially for an RLV, where methane has advantages over RP-1.

I was suggesting another company other than ULA decides to create a new RLV and needs an engine.

How is it already reusable? It's early in development, and re-usability has not been something that AJR has promoted as a part of AR-1 - unless I missed it.

AR-1 is a candidate for SMART reuse on Vulcan.



A rocket engine is only reusable if you can reuse it. That means it has to be recovered as part of a 1st stage, or by recovering the engine from the 1st stage before it lands in the water (ala Vulcan mid-air engine recovery). And that capability is not necessarily the responsibility of the engine, but of the rocket manufacturer.
A third party buying AR1s would be responsbile for developing the recovery method. I'm not sure what the point of contention with that is? For example, Boeing is buying derived RS-25 engines for the reusable DARPA XS1 Spaceplane instead of going through the expensive and lengthy process of creating an entirely new engine. DC-X used existing engines too.

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Anyone being serious about getting into the launch business is going to survey the competition and see that the two to beat both make their own engines and rockets. So buying an engine that is not built to be used for a reusable rocket is not likely to be popular.
It's not self-evident that the level of vertical integration Blue Origin and SpaceX is the only valid strategy to compete with them. The majority of the industry doesn't do so. For relative latecomers to the RLV market or companies with fewer resources, buying an engine from an external supplier could be a perfectly valid strategy to lower development costs and expedite entry to the market.
"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." R.P.Feynman

Online AncientU

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...
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Anyone being serious about getting into the launch business is going to survey the competition and see that the two to beat both make their own engines and rockets. So buying an engine that is not built to be used for a reusable rocket is not likely to be popular.
It's not self-evident that the level of vertical integration Blue Origin and SpaceX is the only valid strategy to compete with them. The majority of the industry doesn't do so. For relative latecomers to the RLV market or companies with fewer resources, buying an engine from an external supplier could be a perfectly valid strategy to lower development costs and expedite entry to the market.

The majority of the industry (a.k.a. Old Space) has received a wake-up call.  Vertical integration isn't a panacea, but either that or some alternate approach that gets control of costs and allows rapid innovation will be necessary if the intent is to remain a majority.  Political influence can only hold back change for so long.

* See 'auto industry'.
« Last Edit: 10/21/2017 12:49 PM by AncientU »
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Offline hkultala

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If ULA would choose BE-4 over AR-1, then why would anyone else choose AR-1 over BE-4? Especially for an RLV, where methane has advantages over RP-1.

I was suggesting another company other than ULA decides to create a new RLV and needs an engine.


.. and why would that hyphothetical "another company" choose AR-1 instead of BE-4 or some RD-170-derived engine?

It seems practically all new rocket companies are making their engines themself, and the two other new EELV-class launchers under development are using solids to get off the pad.


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A rocket engine is only reusable if you can reuse it. That means it has to be recovered as part of a 1st stage, or by recovering the engine from the 1st stage before it lands in the water (ala Vulcan mid-air engine recovery). And that capability is not necessarily the responsibility of the engine, but of the rocket manufacturer.
A third party buying AR1s would be responsbile for developing the recovery method. I'm not sure what the point of contention with that is? For example, Boeing is buying derived RS-25 engines for the reusable DARPA XS1 Spaceplane instead of going through the expensive and lengthy process of creating an entirely new engine. DC-X used existing engines too.


Even if AR-1 is capable of multiple burns, it is badly suited for reuse;

On a reasonable-sized rocket, it cannot be throttled down enough to allow low enough T/W to land the first stage propulsively.

AR-1 is only suitable for reuse on either
1) a very big rocket.
2) winged ot otherwise expensive recovery

Online Coastal Ron

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For example, Boeing is buying derived RS-25 engines for the reusable DARPA XS1 Spaceplane instead of going through the expensive and lengthy process of creating an entirely new engine.

VTHL systems have been shown to be limited in payload size and weight, so they are not competitors for the majority of the commercial and government launch market. Which means you still need an engine that can take off vertically and either land vertically (via throttling and restarts) or by recovering the engine(s) via parachute before they hit the water. Both of those require tight coordination of features between the engine designers and the rocket body designers - not easy when one of those can't make changes.

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DC-X used existing engines too.

DC-X was an experimental sub-orbital vehicle, and is not relevant to conversations about orbital needs.

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It's not self-evident that the level of vertical integration Blue Origin and SpaceX is the only valid strategy to compete with them.

We do know that traditional reliance on sub-contractor is not a viable competitive strategy when compared to vertical integration, so the only other option would be a 3rd strategy - which apparently no one has attempted to implement successfully.

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The majority of the industry doesn't do so.

I've been in the majority of the industry that doesn't do vertical integration for non-aerospace products, and I can tell you that it's not easy to switch if you are a mature company with mature operations. And SpaceX really only recently proved the advantages of vertical integration DO WORK for the commercial launch industry, so there has hardly been enough time for a full reaction.

But comparing what SpaceX does to the rest of the rocket manufacturers it becomes clear why they are able to iterate and innovate so fast, and that is something the rest of the industry will try to emulate when they can. But like I said, it's difficult to change your company from one mode of manufacturing to the other.

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For relative latecomers to the RLV market or companies with fewer resources, buying an engine from an external supplier could be a perfectly valid strategy to lower development costs and expedite entry to the market.

There is no such thing as a "relative latecomers to the RLV market", since SpaceX only just created it. It's still in it's infancy. And unfortunately you can't get into the EELV launch market without a boatload of money and time, since SpaceX is now 15 years old and Blue Origin is 17 years old.

I will say though that we learned recently that the launch market is focused on having three viable launch providers, and currently SpaceX is one of them. If Blue Origin becomes the 2nd reusable launch provider the market depends on there is still room for a 3rd reusable launch provider - who will that be?

Bottom line though is that the AR-1 doesn't seem to be an option for a launch provider that wants to build an EELV-class reusable launch vehicle.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline Darkseraph

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The hypothetical company could be Aerojet itself. At one point they tried to gain production rights to the Atlas-V using AR-1. Alternatively, another company might choose an aerojet engine to avoid enriching domestic competitors and to avoid any possible sanctions on a foreign engine. The startups that are opting to develop their own engines with the exception of Blue Origin and SpaceX are developing relatively small simple engines for small ELVs because engines in the AR-1 class are beyond their resources and capabilities. The scenario I am describing would involve a new entrant making a rather large RLV to directly compete with Falcon Heavy or New Glenn.

Out of interest, have Aerojet actually published what the throttle range of AR-1 is?
"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." R.P.Feynman

Offline HIP2BSQRE

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The hypothetical company could be Aerojet itself. At one point they tried to gain production rights to the Atlas-V using AR-1. Alternatively, another company might choose an aerojet engine to avoid enriching domestic competitors and to avoid any possible sanctions on a foreign engine. The startups that are opting to develop their own engines with the exception of Blue Origin and SpaceX are developing relatively small simple engines for small ELVs because engines in the AR-1 class are beyond their resources and capabilities. The scenario I am describing would involve a new entrant making a rather large RLV to directly compete with Falcon Heavy or New Glenn.

Out of interest, have Aerojet actually published what the throttle range of AR-1 is?

Then that new company better have a large amount of money to spend.  The launch industry is going to get more competitive in the next 5 years.  The company will be competing against SpaceX, BO, ULA, and possible Northrop.

Offline hkultala

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Out of interest, have Aerojet actually published what the throttle range of AR-1 is?

No, but

1) it's very unlikely to use pintle injector, as only SpaceX and TRW have experience in pintle injectors, an AJR has lots of experience and heritage of other type injectors, and deep throttling was not a goal for AR-1. Deep throttling is much easier with pintle injector based engines.

2) It's nominial thrust is so high, that insanely deep throttling would be needed to get the TWR down enough.

Offline Darkseraph

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Out of interest, have Aerojet actually published what the throttle range of AR-1 is?

No, but

1) it's very unlikely to use pintle injector, as only SpaceX and TRW have experience in pintle injectors, an AJR has lots of experience and heritage of other type injectors, and deep throttling was not a goal for AR-1. Deep throttling is much easier with pintle injector based engines.

2) It's nominial thrust is so high, that insanely deep throttling would be needed to get the TWR down enough.

AFAIK BE-4 has a large throttle range. Is it known to be using pintle injectors?
"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." R.P.Feynman

Offline Patchouli

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However, AR-1 already is a reusable engine and the government have effectively paid for it.

A rocket engine is only reusable if you can reuse it. That means it has to be recovered as part of a 1st stage, or by recovering the engine from the 1st stage before it lands in the water (ala Vulcan mid-air engine recovery). And that capability is not necessarily the responsibility of the engine, but of the rocket manufacturer.

Anyone being serious about getting into the launch business is going to survey the competition and see that the two to beat both make their own engines and rockets. So buying an engine that is not built to be used for a reusable rocket is not likely to be popular.

Maybe there is a government program that could use the AR-1, but it would be hard to see a scenario where a commercial rocket manufacturer would want to use the AR-1.

In theory even the H-1/RS-27 could have been reusable if it was recovered.

http://up-ship.com/blog/?p=5948

Offline Chasm

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The hypothetical company could be Aerojet itself. At one point they tried to gain production rights to the Atlas-V using AR-1. Alternatively, another company might choose an aerojet engine to avoid enriching domestic competitors and to avoid any possible sanctions on a foreign engine. [...]

Hm... How about a bit of political pressure on the RD-181 once Atlas V and RD-180 are basically gone?
That replacement seems somewhat closer. 2 separate engines this time. :)
The third time is the charm as the saying goes.  8) (Counting Antares first stage engines.)

Offline Space Ghost 1962

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Not likely. Antares flies infrequently, no NSS payloads,  requires cheap engines that AJR, and acquired by a firm which appears to be restructuring itself to address defense systems for the next decade, with careful, narrow focus.

Too many incompatible launch systems with too small a manifest. Too much of a distraction?

Offline oldAtlas_Eguy

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Too much speculation on boosters that do not exist even in Power Point.

Wandering OT.

Please get back to the engine itself and AJR status of the engine and contract.

Online Coastal Ron

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AFAIK BE-4 has a large throttle range. Is it known to be using pintle injectors?

I have not seen a reference about that, so I don't know. What is known is that Blue Origin plans to use 7 BE-4 for their New Glenn, so the amount that needs to be throttled would be far less of a range than what an AR-1 would need to do if there were two of them on an Atlas V-class reusable launcher.

If an AR-1 was used to build a Falcon 9 type rocket with 9 engines, based on the greater thrust of the AR-1 compared to the Merlin 1D such a rocket would be in the range of 2.5X as big, since the AR-1 has 500,000 lbf thrust (sea level) vs 190,000 lbf thrust (sea level) for the Merlin 1D. The Merlin 1D can throttle between 100% to 70%, which is an indication of what might be needed from the AR-1 if it were to be used in a stage that can land back on the surface of the Earth.

Was the AR-1 designed to be reused safely 10 or more times? If not then debating this doesn't lead anywhere...
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline Lars-J

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Out of interest, have Aerojet actually published what the throttle range of AR-1 is?

No, but

1) it's very unlikely to use pintle injector, as only SpaceX and TRW have experience in pintle injectors, an AJR has lots of experience and heritage of other type injectors, and deep throttling was not a goal for AR-1. Deep throttling is much easier with pintle injector based engines.

A pintle injector is not a requirement for deep throttling ability. The RD-180 does not use it, and has a pretty wide throttle range. We don't even know if the Raptor engine uses it.

Offline woods170

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How is it already reusable? It's early in development, and re-usability has not been something that AJR has promoted as a part of AR-1 - unless I missed it.

AR-1 is a candidate for SMART reuse on Vulcan.

So is BE-4 and that one is actually being designed and constructed for reuse (given it's role on New Glenn).

Offline Steven Pietrobon

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This article on the BE-4 has some information on the AR-1. The last paragraph is interesting. The list of who else could use AR-1 must be pretty short. OA could use it for Antares, but OA seem to be moving away from that vehicle given they are looking at Altas V for future Cygnus flights. NASA could use them in advanced liquid boosters for SLS Block II, provided that Congress keeps funding SLS in the face of alternative heavy lift from Vulcan, New Glenn, Falcon Heavy and BFR that use (or could use) in-orbit refuelling (or Tanking Mode as Von Braun called it) to reach high TLI masses. New liquid boosters would also be a more expensive option compared to new solid boosters from OA. Everybody else has their own high performance engines.

Perhaps what Aerojet needs is someone to build a clone of Falcon 9 with nine AR-1 engines on the first stage (for 20 MN of thrust) and one AR-1 in the second.

http://aviationweek.com/space/blue-origin-fires-be-4-methane-fuel-rocket-engine

"Aerojet declined to comment about AR1s prospects for powering ULAs Vulcan rockets in light of the successful BE-4 engine firing. We have been talking to them every day since then, says Aerojet Vice President Julie Van Kleeck. We have asked them about their downselect. We are always careful about speculating.

The U.S. Air Force is contributing up to $536 million for development of the liquid oxygen and kerosene-fueled AR1 through the end of 2019.  The engine is designed to generate 500,000 lb. of thrust at sea level. We have [AR1] funding for this year. We are negotiating what next year will look like, says Van Kleeck.

Aerojet has other prospective customers for the AR1 besides ULA, Van Kleeck adds, though she declined to identify them."
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

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