Blue Origin thread.

[tater]

28 minutes ago, Barzon said:

It's probably a safe assumption. If not, well, all we can do is wait for more information.

I suppose I had assumed it was the first submission, maybe not. FWIW the BO mockup was removed from JSC from what I was told.

[Barzon]

9 minutes ago, tater said:

I suppose I had assumed it was the first submission, maybe not. FWIW the BO mockup was removed from JSC from what I was told.

by first submission are you meaning ILV? Because we know what the ILV PV looked like, and it did not look like that.

And the mockup in the tweet was located at KSC, not JSC

[sevenperforce]

20 hours ago, Barzon said:

20 hours ago, tater said:

20 hours ago, Barzon said:

If it helps, you can probably get a rough estimate for the dimensions of the habitat from this tweet, if it hasn't been posted already.

The question is if this is the same vehicle.

It's probably a safe assumption. If not, well, all we can do is wait for more information.

I'm pretty sure it's not the same vehicle. The new design has a completely different OML so they would design the interior from scratch.

To @tater's earlier point, it's possible that they could have the engine(s) protruding into a bulkhead inside the crew cabin, like the New Shepard crew capsule. Not sure how much space would be required, though.

According to this source, the new HLS lander is 16 tonnes empty and will have a mass of over 45 metric tonnes with full props. But from the lunar surface, it will only need about 2.6 km/s of dV to get to Gateway. Let's say 2.7 km/s for margin. Assuming the BE-7(s) can get into the ballpark of 445 seconds specific impulse, the liftoff mass from the lunar surface will be about 29 tonnes. Liftoff mass for the Lunar Module was 4.7 tonnes and the engine delivered 16 kN of constant thrust, delivering a relatively anemic two lunar gees (0.35 gee_Earth). I'm sure the HLS architectures will need more than that. If we say three lunar gees, that's the equivalent of an Earth T/W ratio of 1.4, which is considered pretty sporty. So we'd be looking at needing ~145 kN off the lunar surface, meaning at least three BE-7s are required.

If they have a cluster of three BE-7s at the center, then you're looking at needing a 2.6-meter-wide circle space for clearance:

Should be enough to put some storage, at least.

 

That's with a notional 6.5-meter OML on the lander, assuming they go right up to the max volume capacity of New Glenn.

[tater]

25 minutes ago, sevenperforce said:

Assuming the BE-7(s) can get into the ballpark of 445 seconds specific impulse

I saw the number 453 actually quoted someplace—maybe in the NASA doc that came with the announcement?

Apparently Bezos said the Isp was 453s

[Barzon]

- First vertical firing of a BE-4

- First dual BE-4 firing

- First firing of a BE-4 on something other than a test stand

 

[Barzon]

 

 

 

Edited June 12, 2023 by Barzon

[Barzon]

 

 

[RCgothic]

O_o

[tater]

 

[tater]

 

[Spaceception]

New Glenn reusable upper stage, similar concept as Stoke with an aerospike and actively cooled heatshield.

 

[AckSed]

Good luck there, BO.

[sevenperforce]

JARVIS has emerged!

I should note that the original Actively-Cooled Heat Shield System and Vehicle Including the Same patent by Stoke, establishing the concept of an engine which uses heat from an actively-cooled shield to circulate the coolant, was filed in August 2020 and claims priority to a prior filing from December 2019, and Stoke's Augmented Aerospike Nozzle, Engine Including the Augmented Aerospike Nozzle, and Vehicle Including the Engine patent was filed August 2021 and claims priority to November 2019. In contrast, Blue Origin's patent above was filed in July 2022 and claims priority to December 2021. So Blue Origin seems to be solidly behind the patenting curve here. Even Stoke's most recent Annular aerospike nozzle with widely-spaced thrust chambers, engine including the annular aerospike nozzle, and vehicle including the engine patent, despite being filed in April 2022, claims priority to April 2021, predating all priority by Blue Origin.

I'll post more over in the Stoke thread, but I did note that their latest patent includes a depiction of a non-axisymmetric heat shield which would provide lift during re-entry at 0° AOA, although it's unclear how that would interact with the aerospike expansion in vacuum.

 

One of the nifty things about BO's patent is the "plurality of scarfed nozzles" depicted around the heat shield:

As Elon Musk has pointed out, one of the reasons that aerospikes suffer is that the primary challenge in rocket engine nozzles is getting the exhaust to go DOWN, and aerospikes aren't great at that. Actually angling and "scarfing" the nozzles into the heat shield like this will make the recessed nozzle surface present a more consistent surface against which the exhaust can expand, reducing intramolecular cosine losses, and it also protects the engines more directly than Stoke's design seems to.

An element very similar to Stoke's design (and potentially grounds for a patent infringement battle) is that "The heat shield may be actively cooled [and]  The heat shield may include a cooling circuit configured to dissipate heat encountered during reentry of the upper stage." They also suggest "secondary fluid injectors" which may eject fluid (presumably from an open/bleed expander cycle exhaust) along with the scarfed thrust nozzles to help shape the plume, which seems to be the configuration depicted here:

Later on they contemplate that the heat shield would "be constructed of thin face sheets separated" by spacers and that "turbine exhaust gas is fed directly into the space between the face sheets and exhausted into the space . . . inside the annular engine exhaust stream through orifices in the outer sheet." Using some sort of base bleed in an aerospike design is a well-known way to improve efficiency (for example, here). 

It looks like they are considering both a closed expander design (using numerous BE-7 turbine units) and an open/bleed expander design (using one or more BE-3U turbine units), depending on whether they use the base bleed or not. The patent explicitly states that their design saves development time by "repurposing turbomachinery (e.g., powerpacks) and thrust chambers designed for other engines" and references designs being created "for use in other space vehicles." Later on, it gives the non-limiting example of using "two BE-3U powerpacks" to operate the nozzles but notes that as many as five or more powerpacks could be used. BO contemplates that they could "power down some number of powerpacks and/or nozzles to meet thrust requirements" for certain aspects of a mission; this would require that the various thrust nozzles be plumbed to alternating turbopumps so as to keep the thrust vector consistent.

They suggest a 23-foot diameter vehicle and a 21-foot-diameter ring of engines which creates, effectively, a single 21-foot-diameter nozzle. They anticipate a specific impulse of 395-425 seconds in one configuration, 400-420 seconds in another configuration, and 405-415 seconds in a third configuration; these configurations are not clearly differentiated. They anticipate that for the two-BE-3U-powerpack configuration, only a single powerpack would be used for vertical landing, with sea level thrust of "about 100 klbf" and throttling capability down to as low as 20%. They talk about each thruster producing 2000 lbf in some configuration but it's not clear how many thrusters they are envisioning with that thrust level. Given that the BE-3U is expected to produce as high as 160 klbf in vacuum, this would imply probably thirty thrusters plumbed to each of the two powerpacks.

 

[Royalswissarmyknife]

A great year for Actively Cooled Heatshield Fans!

[tater]

@sevenperforce, so in all the cases it seems like stoke holds the patent priority? Does this result in some ugly legal wrangling you think?

[darthgently]

1 hour ago, tater said:

@sevenperforce, so in all the cases it seems like stoke holds the patent priority? Does this result in some ugly legal wrangling you think?

Would be fun if Stoke offered to licence all of it to BO in exchange for Stoke use of "scarfing" of nozzles wrinkle plus 5% of BO launch services sales involving the patented concept in perpetuity 

[sevenperforce]

16 hours ago, tater said:

@sevenperforce, so in all the cases it seems like stoke holds the patent priority? Does this result in some ugly legal wrangling you think?

My patent law experience is not extensive, but IMHO the levels of potentially infringing overlap aren't very significant. You can't patent physics, after all, and just because a patent might describe certain attributes in conjunction with its core aspects doesn't mean all of those attributes are protected.

But yes, Stoke holds patent priority on everything here.

The core of the Stoke patent is the dual use of the expander cycle with the heat shield cooling manifold to pump the coolant during re-entry. It's a truly novel idea and I think it will stick. The question is whether BO tries to copy that approach or not. 

[darthgently]

6 minutes ago, sevenperforce said:

The core of the Stoke patent is the dual use of the expander cycle with the heat shield cooling manifold to pump the coolant during re-entry. It's a truly novel idea and I think it will stick. The question is whether BO tries to copy that approach or not.

And on the BO patent side the nozzle scarfing seems promising and something Stoke may be interested in if it pans out.  I'm picturing it as maybe working to keep the flow both near the shield on the inboard side while still allowing the flow to expand aft on the outboard side.  The inward flow against the shield would create a high pressure peak at the center of the shield also resulting in aft directed thrust. Or something like that.  Any ideas on what I'm missing? 

[sevenperforce]

4 hours ago, darthgently said:

And on the BO patent side the nozzle scarfing seems promising and something Stoke may be interested in if it pans out.  I'm picturing it as maybe working to keep the flow both near the shield on the inboard side while still allowing the flow to expand aft on the outboard side.  The inward flow against the shield would create a high pressure peak at the center of the shield also resulting in aft directed thrust. Or something like that.  Any ideas on what I'm missing? 

You're absolutely right.

It looks like Stoke really started off with the idea of the actively-cooled heat shield and sort of stumbled onto an aerospike design, while BO appears to have been designing this as an aerospike from the ground up.

Stoke may have better luck with its landing burns than BO, since they can just accept flow detachment.

[darthgently]

23 minutes ago, sevenperforce said:

Stoke may have better luck with its landing burns than BO, since they can just accept

Stoke is focusing on good throttle control of the engines rather than swivel for steering so that should pay off nicely for controlled landings also. 

I can't even visualize the effects of differential throttling of the scarfed design engines.  It seems if you throttle down the port side , the starboard side engines would push the central pressure point toward port, which would somewhat cancel the throttling down on the port side, making it more complex.  Not sure

[sevenperforce]

17 hours ago, darthgently said:

I can't even visualize the effects of differential throttling of the scarfed design engines.  It seems if you throttle down the port side , the starboard side engines would push the central pressure point toward port, which would somewhat cancel the throttling down on the port side, making it more complex.

I don't think the scarfing will cause overmuch problems for differential throttling. It feels like you're imagining secondary plume interactions, but in a supersonic flow there is no upstream propagation of plume interactions, so any change in the wake pressure across the heat shield will be very very minor compared to the impact of the throttling itself.

Thinking about it in the context of equal and opposite forces:

The equal and opposite forces from each thruster are split between the forces on the chamber/injector, which have a significant medial-radial component (green) but balance each other out, and the forces on the scarfed expansion surface, which have a lower medial-radial component and progressively greater superior component (blue):

By downthrottling on one side, the medial-radial component of the chamber force decreases on that side, causing a direct torque on the opposite side; it also causes the center of vertical force to shift away from that side, which also creates a torque.

If anything, differential throttling of a design like this may result in too much authority and lead to oscillations that are hard to damp, like putting a Vector engine underneath too lightweight of a rocket in KSP. It will be less of an issue in space but it might cause issues with landing.

[tater]

 

[Jacke]

On 8/3/2023 at 12:18 PM, tater said:

 

I really wonder at what will be the merged corporation's name. 

[tater]

1 hour ago, Jacke said:

I really wonder at what will be the merged corporation's name. 

l almost fired Mai Tai out my nose. Well played.

[darthgently]

6 hours ago, Jacke said:

I really wonder at what will be the merged corporation's name. 

Given the long delays to launch, I'm thinking this would not only be the most entertaining outcome, but the most honest one

Edited August 5, 2023 by darthgently