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