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Blue Origin thread.


Vanamonde

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12 hours ago, sh1pman said:

Maybe we will see a radical price reduction from SpaceX when NG starts flying. Until then, no reason for SpaceX to leave money on the table. So, turns out, you need TWO rocket companies with reusable rockets to see the actual reduction in space access cost.

I mean, 1 spaceX launch is 61 Million, from the 100 million typical of heavy satellites. This isn't cheap enough?

And also, two rockets from TWO companies.

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5 minutes ago, Xd the great said:

I mean, 1 spaceX launch is 61 Million, from the 100 million typical of heavy satellites. This isn't cheap enough?

It’s 50M now (for a reused rocket), and we have no idea how much they spend on one such launch. Maybe it’s 25M. Then there’s room for further price reduction.

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On 10/22/2019 at 2:24 AM, mikegarrison said:

I noticed a lot of nuts in the closeups have provisions for lockwires, but there are no lockwires. I wonder if that's because this build is just for show, or if they just use those nuts but don't use lockwires.

Its because the mechanics know the engineering types like yourself will make them change it another 10 times before the first test.
I'm just ribbing you, @mikegarrison, I'm curious too. At least the entire thing isn't day-glo orange with FTI so we can see the plumbing.

Edited by Meecrob
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It might be possible to create a very broad estimate of New Glenn performance based on information in the NG user's guide. For example, we know that the NG upper stage provides 1,060 kN of thrust in comparison to the 490 kN of the BE-3 on New Shepard. Naively, one might assume this 8.2% boost in thrust is the result of a better expansion ratio and solve the ideal gas expansion equation, using an estimated heat capacity for probable hydrolox mixture ratios, to guess at chamber pressure and do the math from there to get isp. But that assumes mass flow is the same for both engines, and ignores the fact that the BE-3 uses combustion tap-off while the BE-3U is an open expander cycle.

We can, however, estimate the volume of the second stage tanks from imagery in the NG User's Guide, then divide by stage burn times to get mass flow. Thrust over mass flow gives specific impulse.

Pixel counting from the New Glenn User's Guide suggests an LH2 tank approximating a cylinder 7 meters wide and 12.55 meters long. It suggests a LOX tank comprising an 0.72 m wide band with spherical caps (radius 3.96 m, height 2.51 m) on both ends.

The volume of a spherical cap is pi*h^2(3R-h)/6 or in this case 30.32 cubic meters, so the total volume of the LOX tank is 30.87 * 2 + 27.71 = 89.45 m^3. Total volume of the LH2 tank is 483.15 m^3. This suggests 34.21 tonnes of LH2 and 102.1 tonnes of LOX, representing an O/F mixture ratio of 2.98:1, which doesn't seem it could possibly be correct. Maybe an open expander cycle dumps excess hydrogen into the exhaust like crazy? I don't know.

But taking our numbers at face value, we end up with 136.31 tonnes of propellant. The NG User's Guide states that for nominal 250-km perigee GTO missions, the first stage burns for 618 seconds to provide LEO insertion followed by a 99-second burn for GTO injection to a 35,786 km apogee. However, it states that for a notional LEO mission, it burns for just 600 seconds with no restart. It states, "initial launches are planned to carry conservative flight performance reserves for enhanced service reliability and vehicle recoverability."

So these numbers do not represent full stage performance. It's obvious that something is wrong when I continue through the rest of the math. At the 717-second burn of a GTO mission, I would be looking at a mass flow rate of 190.11 kg/s, which would suggest a wild specific impulse of 568 seconds.

If I take the 102.1 estimated tonnes of LOX and just plug in ordinary numbers for LH2 (let's suppose a 5.5:1 O/F mixture ratio), I get 18.56 tonnes of LH2, for a total propellant load of 120.66 tonnes on the second stage. Burning all that in 717 seconds suggests 168.3 kg/s, which gives a specific impulse of 642 seconds, which is even worse. If I reverse it and take the 34.21 estimated tonnes of LH2 with a mixture ratio of 5.5, I get 188.155 tonnes of LOX (don't know where they'll put it, mind you, but that's another question) and a total of 222.37 tonnes of propellant. This equation suggests 310 kg/s, which comes to a specific impulse of 349 seconds, which is obviously erring in the opposite direction.

It is more likely that the 717-second burn uses a lower throttle setting to reduce gee-loading on the lower-mass payload. If we take the 600-second burn of a higher-mass LEO mission as a full-throttle burn from start to finish, then we get a mass flow rate of 227.2 kg/s, which suggests a specific impulse of 475.6 seconds. This is much closer to reality (though obviously inflated, probably by my ignorance of a lower-throttle terminal burn period).

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  • 3 weeks later...
4 hours ago, StrandedonEarth said:

But that view tho....

My guess is that they are milking the marked.

Very cool to be on the first flight. After that its just an amazing experience. 

Its MMO (think WOW, FF14 or elder scroll online) economic. 
Then some new nice gear or outfit is released prices is very high as its rare, but if drop rate is constant its become more and more common and in the end you can hardly give it away as its not used up and you get new shiny stuff at intervals. 

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5 hours ago, StrandedonEarth said:

But that view tho....

Yeah. See, if I had the money, I’d totally drop it on this. 
 

1 hour ago, magnemoe said:

My guess is that they are milking the marked.

Very cool to be on the first flight. After that its just an amazing experience. 

This. Believe it or not, but demand will still exceed supply once they start flying, I think. Once they’ve got more pods and boosters completed and can fly more often, the price will come down. Maybe not to Joe Schmo levels, but a single hundred-thousand is still better than multiples.  

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  • 3 weeks later...
On 11/18/2019 at 1:40 PM, CatastrophicFailure said:

Objection sustained. -_-

 

Partially.

Looks like the specific finding is that the GAO wants the USAF to treat all providers as independent bids, rather than selecting a pair of providers that complement each other best.

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6 hours ago, mikegarrison said:

Looks like the specific finding is that the GAO wants the USAF to treat all providers as independent bids, rather than selecting a pair of providers that complement each other best.

Yeah, this doesn't change all that much, if anything. The selection is still going to be 60/40, and SpaceX is getting one of them. I can't see why ULA doesn't get the other, since part of their submission has actually flown, vs none of BO's submission.

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Just now, Ultimate Steve said:

The one time I'm in est they have a launch in cst.

Probably won't get to watch it live though.

They're always in the same time zone. Van Horn is not in the bit of TX in the Mountain time zone.

 

And... it's a weather scrub, anyway.

 

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17 minutes ago, Geonovast said:

I think you're off an hour.  Stream shows T-33:00 and that it's scheduled for 10:00 am EST (it's 9:27 am EST at the time of this post)

Reset to 74 min from now, as per their tweet.

(ie: set to 11am EST)

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