Artemis does not rely on New Glenn launching crewed missions. Orion carries people to Gateway to Blue Moon, same as Starship.
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Right, because New Glenn launches Blue Moon and their refueling tug and everything else, but not the NASA crew.
Not sure on your question, we were originally talking New Glenn (I thought). Blue Moon is reusable and they are launching test articles ahead of the real mission, so they can have backup lunar units available down the road.
Scott Manley has a new video on the BO lander with lots of well informed analysis as usual. No doubt some of you already know this, but I learned that the lander is a mono-propellant system (including the RCS!) with three BE-7 engines. It appears to just barely fit into the New Glenn fairing. Payload of 20 tons to the lunar surface in reusable mode.
The overall design is a radical change from their previous lander proposal that lost out to SpaceX.
The overall design is a radical change from their previous lander proposal that lost out to SpaceX.
Well, I had originally questioned the idea of New Glenn being human rated by 2028 based on the point in the Source Selection Document (sorry, bad link on earlier post) that said: "...the plan to launch duplicate landers for the 2027 uncrewed flight test and 2028 crewed demonstration missions" to which you said New Glenn is not needed for crewed missions.
From what I'm reading, it seems as if their lander implies launching on New Glenn (or requires it due to size?). Scott Manley's video above says "It is sized for New Glenn", and he also goes in to some detail about those specs...
So I guess it' my turn to not be sure what you meant when you replied saying New Glenn wasn't needed?
Ah. What I said was
Blue Moon needs Blue Glenn to get to space.
Blue Glenn does not need to be human rated to support HLS.
Maybe I misunderstood your original statement, I though you were referring to New Glenn becoming human rated, was "it" referring to the lander?
I think the Starship human rating timeline is based on an Earth launch and return mission, not moon landing and return.
OK, looks like we may have been talking past each other a bit... and the whole system is admittedly a bit involved.
So, when that doc says there is a plan to launch "landers" (in context the new proposed large BO lander) for a crewed demo mission in 2028, that implies it needs a launch vehicle large enough and human rated, no?
The only ships large enough for this would be New Glenn and Starship, right? (Manley says this in his video).
Jeff deciding to launch on Starship is... "unlikely".
Hence, this seems to imply they expect New Glenn to be human rated by 2028, if I have the above correct.
No, not as I understand it.
The BO lander launches on New Glenn. No one is inside the lander at that point.
The lander goes to LEO and then leaves orbit and rendezvous with the Gateway. It is not carrying crew.
The humans launch in the Boeing Orion capsule on the SLS rocket to LEO, and the capsule then which goes to the Gateway. There they transfer to the BO lander and descend to the lunar surface.
For the return, everything runs in reverse.
I hope I have that right.
Ah, ok. Appreciate the clarification. And to @mongo, for pointing it out initially, I just didn't' grasp it.
Scott Manley explains an interesting patent filed by BO Blue Origin Patent Shows Heat Shield-Aerospike Combo For New Glenn
It potentially relates to the New Glenn second stage, using a ring of engines pointing inwards to create an “altitude compensating aerospIke” that is effective not only in a vacuum but also at sea level when landing.
Intriguing, though Scott points out that we have no evidence that BO plans to use such a design on New Glenn.
It potentially relates to the New Glenn second stage, using a ring of engines pointing inwards to create an “altitude compensating aerospIke” that is effective not only in a vacuum but also at sea level when landing.
Intriguing, though Scott points out that we have no evidence that BO plans to use such a design on New Glenn.
TunaBug
Member
+1 for Manley knowing that filing a patent is not related to implementing the idea.
But wouldn’t it be cool to see somebody using an aerospike for a production vehicle?
Scott is a very smart person; he doesn’t miss much. And when he does make a mistake he acknowledges it. The real test of a smart person.
It would be very cool, though what that patent describes is not the typical aerospike design. It seems more complex; does the BO design use 30 separate engines?
I wonder how much of an aerospike effect is gained just by having multiple engines. Surely the center engine of the Saturn V had better performance than the outer engines. It had a more constant pressure environment, regardless of altitude. Something like the Starship booster should get that same effect in spades. Only the outside portion of the outer engines is exposed to changing ambient conditions.
Does anyone here know anything about this? I was wondering if that's why Starship uses sea level Raptors for the inner engines and vacuum Raptors for the outer. Sadly, Occam's Razor would suggest that it's no more complex than wanting sea level performance for powered landings.
Increased ambient pressure due to surrounding engines actually hurts engine performance.
Do engines in the middle of an engine cluster get impulse benefits?
As to positioning: the sea level engines need to gimble enough to maneuver their force vectors around the center of mass, so central is best versus perimeter. A 4m offset with a center of mass at 25m CG requires 9 degrees of gimbal just to be inline with the CoM.
Thanks for the link. As I read that, the crux of the criticism about loss of thrust is that the surrounding engines produce an overpressure environment for the center engines, resulting in under-expansion of the exhaust from the center engines. Clearly, that's bad. But my point is that it's a known overpressure environment, and it seems to be more stable than the ambient environment. So the bells on the engines should be designed for that environment, not the ambient one. In short, the bells on the interior engines should be shorter because of the stable overpressure provided by the surrounding engines.
An interesting point from that link is that vortices develop around the protruding bits of the engines. The rear end of a rocket is not streamlined, so air gets worked around in there. I notice that the booster has protruding engines, while Starship does not. I wonder if the vortices are considered a good thing because they carry away a lot of heat while in atmosphere. They reduce the performance of the rocket, so they must be left protruding for a good reason. Starship has no need of that vortex cooling effect because there's no atmosphere when it's running it's engines on the way up. On the way down, the air is being forced up into the engine chamber.
Note that the Blue Origin document shows streamlined mounting.
Good point about gimballing influencing engine position.
Less expansion is less isp (less efficiency). Ambient pressure is why engines grt higher isp with altitudeand vacuum have larger bells. The only optimization available would be shortening the bell slightly which only reduces mass, no thrust or isp improvement.
The ship's engines are recessed because the ship stacks on the booster and test stands so it needs the walls there (technically, they could be on the booster, but that complicates things).
The booster engine protrude outside the tank circumference and the OLM clamps attach attach to the walls above them. No need to add mass just to surround them (plus it would need a lot of bracing to survive RTLS)
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