New Glenn 9x4 discussion

[Jim]

Supposedly, according to Bezos like a year+ ago, they'll be moving to "monocoque" tanks for the GS2. By which he seemed to mean neither orthogrid nor skin and stringer. Just skin, that's thick enough to handle the structural loads, and they just take the mass hit.

not really, see Centaur

[Jim]

He is erroneously referring to this structure I've outlined in red is actually added structure to the 9 x 4's GS2. Note the corrugation on the outside, which indicates a true boat tail compartment rather than just MLI blankets surrounding the BE-3U turbomachinery. 

T

No, that is not a boat tail.  A boat tail is tapered from wide to narrow.  That structure would be part of the thrust structure.

[StraumliBlight]

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

I calculated the same diameter from 3d modelling.

[StraumliBlight]

9x4 roles are starting to appear:

Structural Design Engineer II - New Glenn Upper Stage [Dec 11]

This role supports the development of the 2nd Generation of New Glenn, a heavy-lift orbital launch vehicle capable of routinely carrying people and payloads to low-Earth orbit, geostationary transfer orbit, cislunar, and beyond.  This position will be directly involved in the design of the next progression of New Glenn Payload Accommodations hardware, including the larger diameter 8.7M payload fairing and adapters.

Might be for a reusable second stage or a deorbit kit:

Mechanical Systems Engineer II - New Glenn Upper Stage [Dec 11]

As part of a small, passionate and accomplished team of experts, you will support the design, development, and test of launch vehicle mechanical and decelerator systems. Your primary focus will be supporting re-entry and mechanical system design development that are critical to enabling safe, reliable, and cost-effective spaceflight.

[...]

Participate in the entire design cycle of aero-decelerator and mechanical subsystems, including conceptual and detailed design, trade studies, structural analysis, development testing and qualification.

[...]

Experience in aerospace designs such as separation systems and/or deployable devices.
Experience with re-entry decelerator systems and devices such as trailing parachutes, inflatables, etc.

[sstli2]

I think it's likelier for re-entry and recovery of fairings, given the mention of parachutes.

They have been hiring for 9x4 roles for a while, they just didn't put it in the job description until now, aside from a mistake early this year that was well-noted in this forum.

[JEF_300]

Supposedly, according to Bezos like a year+ ago, they'll be moving to "monocoque" tanks for the GS2. By which he seemed to mean neither orthogrid nor skin and stringer. Just skin, that's thick enough to handle the structural loads, and they just take the mass hit.

not really, see Centaur

No. Bezos, in this case, was talking about aluminum-lithium tanks, and using them on a slot-in upgrade to the current GS2. It cannot possibly be a centaur-like pressure stabilized situation.

[briantipton]

Supposedly, according to Bezos like a year+ ago, they'll be moving to "monocoque" tanks for the GS2. By which he seemed to mean neither orthogrid nor skin and stringer. Just skin, that's thick enough to handle the structural loads, and they just take the mass hit.

not really, see Centaur

No. Bezos, in this case, was talking about aluminum-lithium tanks, and using them on a slot-in upgrade to the current GS2. It cannot possibly be a centaur-like pressure stabilized situation.

Why not? Monocoque construction works really well in stainless steel, but it can be applied to aluminum tanks as well. I believe Falcon 9 Lox tanks are monocoque.

[JEF_300]

Supposedly, according to Bezos like a year+ ago, they'll be moving to "monocoque" tanks for the GS2. By which he seemed to mean neither orthogrid nor skin and stringer. Just skin, that's thick enough to handle the structural loads, and they just take the mass hit.

not really, see Centaur

No. Bezos, in this case, was talking about aluminum-lithium tanks, and using them on a slot-in upgrade to the current GS2. It cannot possibly be a centaur-like pressure stabilized situation.

Why not? Monocoque construction works really well in stainless steel, but it can be applied to aluminum tanks as well. I believe Falcon 9 Lox tanks are monocoque.

Re-read my posts. What I am saying GS2 WILL be made monocoque, and WON'T be pressure stabilized like Centaur. Making it like Centaur would require totally different support infrastructure to keep it structurally stable during ground operations, making it functionally a totally new upper stage, not an upgrade.

[briantipton]

Supposedly, according to Bezos like a year+ ago, they'll be moving to "monocoque" tanks for the GS2. By which he seemed to mean neither orthogrid nor skin and stringer. Just skin, that's thick enough to handle the structural loads, and they just take the mass hit.

not really, see Centaur

No. Bezos, in this case, was talking about aluminum-lithium tanks, and using them on a slot-in upgrade to the current GS2. It cannot possibly be a centaur-like pressure stabilized situation.

Why not? Monocoque construction works really well in stainless steel, but it can be applied to aluminum tanks as well. I believe Falcon 9 Lox tanks are monocoque.

Re-read my posts. What I am saying GS2 WILL be made monocoque, and WON'T be pressure stabilized like Centaur. Making it like Centaur would require totally different support infrastructure to keep it structurally stable during ground operations, making it functionally a totally new upper stage, not an upgrade.

You're right, I mis-interpreted your post.

[deltaV]

https://www.blueorigin.com/es-MX/new-glenn/9x4

Powered by four BE-3U engines, 9x4’s second stage carries 70 metric tons to low Earth orbit, 14 metric tons to Geostationary Orbit Direct, and 20 metric tons to Trans Lunar Injection.

Do we know if those figures are with the first stage reused or expended? (Companies sometimes quote expendable performance even for vehicles that are planned to be reused to make their vehicle look better.)

I bet those figures are expendable for the following reason: 9x4's LEO/GEO payload ratio is 70/14=5.0, which is comparable to almost-three-stage expendable vehicles' ratios such as Vulcan VC6's 3.9, Vulcan VC2's 5.4 and Falcon Heavy expendable's 6.8. Two stage vehicles usually have a much larger ratio especially with first stage reuse, e.g. Falcon ASDS and Starship have infinite ratios since they can't do direct GEO and 7x2's ratio (dunno if it's which is with reuse) is 38870/1440=27.0. (The payloads I used to calculate the ratios for the other vehicles are from https://elvperf.ksc.nasa.gov/Pages/Query.aspx viewed many months ago using 200 km LEO, I forget the inclination, and using C3=24 km^2/s^2 as an approximation of direct GEO since that takes roughly the same 4.27 km/s beyond LEO delta-vee.)

If those figures are expendable then 9x4 has roughly half the capability of SLS when expended (SLS block 1B can do 42 tonnes to TLI) so 9x4 is Falcon Heavy class, not SLS/Saturn V/Starship class. Still, 70 tonnes to LEO expendable and some fraction of that reusable is plenty of performance for every plausible need in the next few decades including crewed exploration of the moon and Mars. IMO unless the US government makes a silly requirement for a larger launcher Blue should probably not design any more vehicles (e.g. New Armstrong) until Blue gets second stage reuse working.

[meekGee]

https://www.blueorigin.com/es-MX/new-glenn/9x4

Powered by four BE-3U engines, 9x4’s second stage carries 70 metric tons to low Earth orbit, 14 metric tons to Geostationary Orbit Direct, and 20 metric tons to Trans Lunar Injection.

Do we know if those figures are with the first stage reused or expended? (Companies sometimes quote expendable performance even for vehicles that are planned to be reused to make their vehicle look better.)

I bet those figures are expendable for the following reason: 9x4's LEO/GEO payload ratio is 70/14=5.0, which is comparable to almost-three-stage expendable vehicles' ratios such as Vulcan VC6's 3.9, Vulcan VC2's 5.4 and Falcon Heavy expendable's 6.8. Two stage vehicles usually have a much larger ratio especially with first stage reuse, e.g. Falcon ASDS and Starship have infinite ratios since they can't do direct GEO and 7x2's ratio (dunno if it's with reuse) is 38870/1440=27.0. (The payloads I used to calculate the ratios for the other vehicles are from https://elvperf.ksc.nasa.gov/Pages/Query.aspx viewed many months ago using 200 km LEO, I forget the inclination, and using C3=24 km^2/s^2 as an approximation of direct GEO since that takes roughly the same 4.27 km/s beyond LEO delta-vee.)

If those figures are expendable then 9x4 has roughly half the capability of SLS when expended (SLS block 1B can do 42 tonnes to TLI) so 9x4 is Falcon Heavy class, not SLS/Saturn V/Starship class. Still, 70 tonnes to LEO expendable and some fraction of that reusable is plenty of performance for every plausible need in the next few decades including crewed exploration of the moon and Mars. IMO unless the US government makes a silly requirement for a larger launcher Blue should probably not design any more vehicles (e.g. New Armstrong) until Blue gets second stage reuse working.

"plenty of performance for every plausible need in the next few decades"?

Forget plausible. It doesn't have enough performance for ANY of the currently discussed plans, EXCEPT for Artemis, maybe.

It's not enough to compete with Starlink, not enough for orbital compute, not enough for Mars colony, or even for a permanent moon base.

Even Starship, which is 5 times larger and rapidly reusable, needs to operate in the 10s of launches per day to achieve these goals.

--

The 9x4 is similar to FH (both capacity and mode of operation), it's just brand spanking new and not a hack like FH was.

If it weren't for Starship, and had it showed up 5-10 years ago, NG would have had many advantages over Falcon, for projects that were on the table then. (Like initial Starlink)

But that's a different timeline. Being a tad better than FH or SLS is not remotely good enough right now.

[deltaV]

Current New Glenn is ~7 t to TLI per NASA LSP. Extrapolating based on the 49% booster thrust increase bumps that to 10.5 t. There's a slight increase in performance from improved mass ratios from subcooling, and from increased upper stage thrust, but neither of those seem like they would get it to 20 t.

NASA LSP ground rules for Blue Origin includes "First stage recovery has been accounted for in the performance capability." As I noted in my last post the 9x4 figures appear to be expendable. This is probably why the high energy performance is much better for 9x4 than in LSP.

[leeloodallasmultipass]

Since Blue pitched it for constellation deploying and all future plans require much higher cadence, it is unreasonable to assume 94 will be expanded(would be too expensive). Honestly the claim smells cope.

[meekGee]

Since Blue pitched it for constellation deploying and all future plans require much higher cadence, it is unreasonable to assume 94 will be expanded(would be too expensive). Honestly the claim smells cope.

How they use it is up to them.  It still lifts off with only 9x 500 kLbf engines, and even if they find another 30% in engine upgrades, that's the basic limit.

It's an FH (5,000 kLbf) equivalent. A lot more elegant, no argument there, but still basically the same thing.

As for Starship, New Glenner is a 9x4, not a 35x9.

So the upshot is:  Full reusability is possible (like it was for FH) but not terribly alluring. Low altitude constellations don't benefit much from the high ISP second stage.

Maybe high altitude constellations (orbital compute) could use a high ISP second stage, but NG's too small for that.

The game has shifted a lot in the last few years. The only launcher ready for the new game is SS/SH.  NG, 7x2 or 9x4, is fighting an old war.

[jongoff]

Do we know if those figures are with the first stage reused or expended? (Companies sometimes quote expendable performance even for vehicles that are planned to be reused to make their vehicle look better.)

I checked with our contacts at Blue Origin when the news was released last month, and they confirmed that those 9x4 numbers assume first stage recovery. In fact, it sounds like they might not even be open to selling a fully-expendable mission. I was surprised because when they told me about 9x4 back at Space Symposium, they were targeting more like 45mT with first stage reuse.

~Jon

[deltaV]

I checked with our contacts at Blue Origin when the news was released last month, and they confirmed that those 9x4 numbers assume first stage recovery.

Thanks for that insider info. If that's the case why is 9x4 so much better at TLI than the NASA LSP figures for 7x2, as pointed out by envy887:

Current New Glenn is ~7 t to TLI per NASA LSP. Extrapolating based on the 49% booster thrust increase bumps that to 10.5 t. There's a slight increase in performance from improved mass ratios from subcooling, and from increased upper stage thrust, but neither of those seem like they would get it to 20 t.

[JEF_300]

Current New Glenn is ~7 t to TLI per NASA LSP. Extrapolating based on the 49% booster thrust increase bumps that to 10.5 t. There's a slight increase in performance from improved mass ratios from subcooling, and from increased upper stage thrust, but neither of those seem like they would get it to 20 t.

You also have to account for the square-cube law, meaning that as your rocket stage gets bigger, it also gets more efficient (in the payload fraction sense). So a 49% increase in thrust, with a matching tank stretch, will actually increase the payload by more that 49%.

Between the rocket equation being inherently exponential anyway, and the particulars of staging, this can (circumstantially) end up effecting the final payload numbers by a lot more than you'd intuitively think it would.

Also, keep in mind that the upper stage is growing more than the first stage is; a more than 100% increase in thrust from the current GS2, in fact. This means the ∆V split between the stages is probably different on 9x4 than 7x2, and the staging point is probably different, and that makes using 7x2 as a starting point for 9x4 calculations... dicey.

[deltaV]

Also, keep in mind that the upper stage is growing more than the first stage is; a more than 100% increase in thrust from the current GS2, in fact. This means the ∆V split between the stages is probably different on 9x4 than 7x2, and the staging point is probably different, and that makes using 7x2 as a starting point for 9x4 calculations... dicey.

I agree that the larger percentage growth in the second stage thrust than the first stage thrust will change things. But a larger second stage should make 9x4 good at LEO and 7x2 good at high energy. That's the opposite of what we're observing comparing Blue's 9x4 numbers with NASA LSP New Glenn.

[deltaV]

Cross post from the BE-7 thread:

It would really make sense to use this for a new 3rd stage on top of New Glenn 9x4, for high energy launches:

4 BE-3Us in the second stage give almost 400 tonnes of thrust, which gives very small gravity losses with huge second stage and allows lifting 70 tonnes to LEO, but the tanks of this huge second stage are quite heavy and the tank weight eats payload to higher orbits.

But, lets add a smallish third stage with single BE-7.

This stage would only stage at orbital speed, eliminating gravity loss, so the very weak engine would not matter much (only losing small amount of performance due to less oeberth effect)

70 tonnes of initial mass , 30 tonnes of propellant, 40 tonnes of final mass (something like 3.5 tonnes of mass for the stage  and 36.5 tonnes of payload) would get from earth to GTO.

Or for TLI, 28-tonne payload would give delta-v of 3 km/s for this stage. As the staging would happen slightly higher at slightly elliptic orbit due to only 61.5 tonnes of payload weight lifted by the second stage, this should be enough for TLI.

This is about the same than what SLS Block 1 can lift to TLI.

Or, towards Mars: 22-tonne payload would mean delta-v of 3.5 km/s for this stage.
the remaining 300 m/s is easily done be earlier stages, due to only 55.5 tonnes (instead of 70 tonnes) of weight lifted by the second stage.

This is much more than Falcon Heavys 17 tonnes towards Mars.

Could even launch decent-size probes towards outer solar system without slow complicated gravity slings, for example 5-tonne payload would get delta-v of 6.8 km/s.

and as the second stage would only need lift 38.5 tonnes, the staging would happen at considerably higher that LEO, total delta-v might be over LEO+8 km/s

And this is for mass about 6 times bigger than the Voyager probes.


The stage would have quite a long burn time (about 45 minutes)

This stage should also be quite cheap.

[Steve G]

My guess is that any third stage would be a derivative of something already under development rather than a clean-sheet design. Such as based on the Cislunar Transporter with 3 BE-7 engines, or the propulsion system of either of its two lunar landers. The Cislunar Transporter IS the upper stage for large lunar payloads, so a third stage would only find use for non-heavy lunar payloads.