New Armstrong Speculation and Discussion - Thread 2

[Yggdrasill]

I think a vacuum BE-4 would make more sense. It would allow for a lot more propellant on the upper stage and a lot more performance. They would require more engines on the first stage, and swapping around some tank segments.

[DanClemmensen]

I think a vacuum BE-4 would make more sense. It would allow for a lot more propellant on the upper stage and a lot more performance. They would require more engines on the first stage, and swapping around some tank segments.

In the past, OldSpace has designed and built LVs using third-party engines. Lockheed Martin used the RD-180 for Atlas V, which has a long history of more than 100 launches. ULA used the BE-4 for Vulcan.

Maybe BO could purchase a flight-tested advanced full-flow staged combustion methalox engine from a third party that is manufacturing them inexpensively  in high volume?

[AmigaClone]

I think a vacuum BE-4 would make more sense. It would allow for a lot more propellant on the upper stage and a lot more performance. They would require more engines on the first stage, and swapping around some tank segments.

In the past, OldSpace has designed and built LVs using third-party engines. Lockheed Martin used the RD-180 for Atlas V, which has a long history of more than 100 launches. ULA used the BE-4 for Vulcan.

Maybe BO could purchase a flight-tested advanced full-flow staged combustion methalox engine from a third party that is manufacturing them inexpensively  in high volume?

I suspect that neither company involved is interested in having that happen.

If I'm not mistaken in most cases OldSpace companies that manufactured LV stages or even entire LV rarely if ever produced their own engines. One characteristic of NewSpace  is that vertical integration where a company produces both the engines and LVs that use them.

I suspect one of the reasons for that is the fact that many of the OldSpace companies were airplane manufacturers and used to purchasing engines for their aircraft from third parties.

[aporigine]

(snip)
Even if BO was okay with the significantly higher cost of purchasing RL-10s, that ~30 s ISP improvement over the BE-3U comes at the cost of much lower thrust which would necessitate staging later.

That makes sense. Maybe not for this generation, but a hydrolox vacuum engine incorporating staged combustion and excellent t/w (and much greater ease and economy of operation than the RS-25!) would support the value of NG as a vehicle of choice for deep space/science missions.

Though, to dovetail into Yggdrasil’s suggestion — with Raptor showing us what can be done using methalox (in terms of performance and speculatively delivered cost per engine), there might be a BE-(n) not too far in the future that will greatly expand the New Glenn User Manual.

[Skye]

After reading this thread, I’m gonna say it’s gone a bit off-topic. I believe this is meant to be a thread about the engineering (size, engines, diameter, payload, versions etc. Maybe even some concept art! See attached from upthread.), but it’s mostly been about the market. I get that it’s a significant part of this, but this is meant to be “what would it be?” Instead of “what market would it fulfill?”. I want to get into lunar landings, crew variants, engines, size, concepts, payload, all that stuff! Also, most of the thread (well, the last couple pages) have been largely dominated by NG discussion (again, very important, but this is meant to be a thread about NA itself).

I’d love to talk about NA concepts, engineering, etc. And, although market is important, engineering is cool, no other way to put it 

Plus, BO basically has infinite money.

[JEF_300]

(snip)
Even if BO was okay with the significantly higher cost of purchasing RL-10s, that ~30 s ISP improvement over the BE-3U comes at the cost of much lower thrust which would necessitate staging later.

That makes sense. Maybe not for this generation, but a hydrolox vacuum engine incorporating staged combustion and excellent t/w (and much greater ease and economy of operation than the RS-25!) would support the value of NG as a vehicle of choice for deep space/science missions.

I think the potential of a vacuum optimized, hydrolox staged combustion engine, is way under discussed. The RS-25 puts up ~452 seconds of vacuum isp, with ~2200 kN of thrust, and does so while still not being fully optimized for vacuum! If you do optimized for vacuum, we're easily talking about an isp in the 460s, while having as much thrust as you want. I personally think that if some of the lessons from Raptor are applied, the mid 470s could be within reach! And if you want to send hundreds of tonnes to the Moon, that could be pretty helpful.

[lightleviathan]

(snip)
Even if BO was okay with the significantly higher cost of purchasing RL-10s, that ~30 s ISP improvement over the BE-3U comes at the cost of much lower thrust which would necessitate staging later.

That makes sense. Maybe not for this generation, but a hydrolox vacuum engine incorporating staged combustion and excellent t/w (and much greater ease and economy of operation than the RS-25!) would support the value of NG as a vehicle of choice for deep space/science missions.

I think the potential of a vacuum optimized, hydrolox staged combustion engine, is way under discussed. The RS-25 puts up ~452 seconds of vacuum isp, with ~2200 kN of thrust, and does so while still not being fully optimized for vacuum! If you do optimized for vacuum, we're easily talking about an isp in the 460s, while having as much thrust as you want. I personally think that if some of the lessons from Raptor are applied, the mid 470s could be within reach! And if you want to send hundreds of tonnes to the Moon, that could be pretty helpful.

Especially without all the baggage from the 1970s, (yes it has been modernized but old design elements are still present) this notional engine could be amazing for Blue

[Skye]

From thread 1:

One of the more whacky ideas.

Faring reuse, a different take.
They are expensive and heavy, esp. when the rocket gets bigger.  With New Shepard Jeff financed and build a Buck Rogers rocket, why not also something from James Bond? Thinking about You Only Live Twice, Moonraker is more of a destination.

A gigantonormus Black Arrow style fairing on stage 1, encapsulating the rest of the stack.
Very mad approach, but looks are important. Since Jeff seems to be cast as the villian in the Blue vs. SpaceX fight this certainly is a way to gain points on Elon.
Why do it?
- Reuse the fairing obviously
- Fairing loads only on 1st stage, both static and dynamic.
- leading to more fragile upper stages, or rather to stick more fragile insulation (ACES long endurance style) and various unareodynamic and fiddly bits on their exterior for wet workshop ideas. (Handholds, hardpoints, solar, thermal control...)
- Say tri or quad sector fairing. Why so many? Secondary use as drag device. Turning the stage into a really big lawndart. Perhaps something like this to slow down. (But actively held open.) perhaps add in kind of Spaceship One feathering tips.

Well, there I had concers about stack height an now I try to land something real tall...
Hm, actually, not that bad, doing this to NG comes out roughly like F9 fist stage. [Cue one of Bezos laughs.]

Chasm actually predicted Neutron! Well, that or Sir Beck is a user on the forum!

[Robotbeat]

Why didn’t you link to it?

[mn]

From thread 1:

One of the more whacky ideas.

Faring reuse, a different take.
They are expensive and heavy, esp. when the rocket gets bigger.  With New Shepard Jeff financed and build a Buck Rogers rocket, why not also something from James Bond? Thinking about You Only Live Twice, Moonraker is more of a destination.

A gigantonormus Black Arrow style fairing on stage 1, encapsulating the rest of the stack.
Very mad approach, but looks are important. Since Jeff seems to be cast as the villian in the Blue vs. SpaceX fight this certainly is a way to gain points on Elon.
Why do it?
- Reuse the fairing obviously
- Fairing loads only on 1st stage, both static and dynamic.
- leading to more fragile upper stages, or rather to stick more fragile insulation (ACES long endurance style) and various unareodynamic and fiddly bits on their exterior for wet workshop ideas. (Handholds, hardpoints, solar, thermal control...)
- Say tri or quad sector fairing. Why so many? Secondary use as drag device. Turning the stage into a really big lawndart. Perhaps something like this to slow down. (But actively held open.) perhaps add in kind of Spaceship One feathering tips.

Well, there I had concers about stack height an now I try to land something real tall...
Hm, actually, not that bad, doing this to NG comes out roughly like F9 fist stage. [Cue one of Bezos laughs.]

Chasm actually predicted Neutron! Well, that or Sir Beck is a user on the forum!

Link to original post (courtesy of Google search)

https://forum.nasaspaceflight.com/index.php?topic=41160.msg1589169#msg1589169

[hkultala]

I think a vacuum BE-4 would make more sense. It would allow for a lot more propellant on the upper stage and a lot more performance. They would require more engines on the first stage, and swapping around some tank segments.

"vacuum BE-4" as third stage engine makes very little sense. BE-4 is booster engine, big, heavy, low-isp.

For upper stage, high isp is needed but lots of thrust is not needed, especially if there is a second stage under it.

And even for potential two-stage NA, 7 (slightly upgraded) BE-3U's would have lots of thrust and would easily be enough for ~150 tonnes to LEO. And actually, much more, if the staging is high enough:

Upcoming BE-3U variants have almost equal thrust to Merlin 1dvac, but with much better isp, and there should not be any big problems putting 7 of those into same upper stage.

So with expendable upper stage, we should be able to relatively easily get 7x higher payload than Falcon heavy has with just 7 BE-3U engines in the upper stage.

Reusability of course changes the equation considerably, but still those 7 BE-3U's could lift quite a lot.

[Texl1649]

Marcus House asked about New Armstrong the other day.  This reply was interesting. 
https://x.com/twin_sunsett/status/1993581462520840666

[frosty_foxx]

Marcus House asked about New Armstrong the other day.  This reply was interesting. 
https://x.com/twin_sunsett/status/1993581462520840666

Am I missing something? What is interesting about this reply?

[meekGee]

Marcus House asked about New Armstrong the other day.  This reply was interesting. 
https://x.com/twin_sunsett/status/1993581462520840666

Am I missing something? What is interesting about this reply?

Just a statement that NA is not NG++, which I agree with.

[spacenut]

Blue could make a 3 core heavy version of New Glenn 9-4.  However make BE-4U vacuum engine(s) for the second stage and make it fully reusable.  No new development of a new rocket.  OR, make a 12m diameter New Armstrong with about 28 BE-4 engines. 

I say 12m because that is about the maximum barge size for transport to get through the Intracoastal waterways and rivers.  However barge size is 55' x 1180' or about 18m x 39m  Height might be a problem under some bridges.  Might be able to get 14m to 16m.  The Kennedy unloading basin and turn around might be the limiting factor of 12m because the 1960's Nova rocket was to be 12m and the Saturn V was 10m.   

[TrevorMonty]

Hydrolox 2nd stage allows for regenerative cooling eg Stoke's Nova. When comes to 2nd reuse there is something to be said for being late to party. Best to wait and see how well Nova and Starships different approaches to dealing with heat workout.

[sstli2]

This would potentially make the 9 x 4 configuration 10.1 meters in diameter.

I calculated the same diameter from 3d modelling.

An interesting thought experiment - if they kept the 9 BE-4 engines at 640 lbf, and expanded the tank diameter to (1) 8.7m to match the fairing or (2) 10.1m to match the aft section, what would the liftoff thrust-to-weight be? If less than 1.1, what would the thrust of the BE-4s need to be to get above that?

I did some wild guesses on a spreadsheet, scaled known values by volume and/or height, filled in the blanks, and attached the numbers here. I did this on a work PC so I am unable to attach the spreadsheet itself. I get:

- 7x2 - 1.08 TWR
- 7x2 w/ engine upgrades - 1.24 TWR
- 9x4 - 1.36 TWR
- 9x4 with 8.7m tanks - 0.91 TWR (no-go)
- 9x4 with 10.1m tanks - 0.45 TWR (no-go)

The 8.7m tanks become feasible with a BE-4 of about 750,000 lbf (340 tons), with a TWR similar to the current NG. The 10.1m is not even close, you need to more than double the total thrust.

I did this fairly quickly so I'm sure people can poke holes in my assumptions or calculations.

Edit: Removed stale spreadsheet.

[DrTadd]

I just don’t see changing tank diameter in the near future. They have all the tooling and equipment geared for the current diameter. So long as the benders are longer than needed, longer is easy. Tank domes are already sorted.

The lower engine module is a stand alone assembly at the bottom, so it could easily change size to accommodate the extra motors.

[jstrotha0975]

My speculation on New Armstrong is that it is on the back burner and will be delayed further now that New Glenn is getting an upgrade.

[wannamoonbase]

My speculation on New Armstrong is that it is on the back burner and will be delayed further now that New Glenn is getting an upgrade.

If by backburner you mean that it only gets discussed by a few engineers at happy hour I agree.

They have lots to do and learn with NG before thinking about anything larger.