Blue Origin thread.

[tater]

 

[sh1pman]

It’s really loud.

“...and deliver our customers to orbit”

Literally?

[CatastrophicFailure]

10 minutes ago, sh1pman said:

It’s really loud.

In space it will be much quieter. 

[tater]

20 minutes ago, sh1pman said:

It’s really loud.

“...and deliver our customers to orbit”

Literally?

Their current NG customers are satellite operators.

That said, the BO mission has always been to put humans in space.

[sevenperforce]

1 hour ago, tater said:

 

Wait, they are making the BE-3U an expander cycle?

This changes a LOT.

[tater]

Yeah. This is RL-10 territory, and not at 38M a pop.

[wumpus]

16 hours ago, tater said:

Yeah. This is RL-10 territory, and not at 38M a pop.

The BE-3 wiki still says "490 kN thrust', while the RL-10 says "110 kN thrust".  The only way you are getting an expander cycle engine up to 490kN is with at least* 4 nozzles (and we see only one in the tweet).  They say that two is enough, I'm wondering if there is a plan to give each BE-3U two nozzles to allow higher thrust.

* maybe less nozzles, but expander cycles have hard limits for how much thrust/(nozzle+combustion chamber) and it can't be that higher than RL-10.

[tater]

49 minutes ago, wumpus said:

The BE-3 wiki still says "490 kN thrust', while the RL-10 says "110 kN thrust".  The only way you are getting an expander cycle engine up to 490kN is with at least* 4 nozzles (and we see only one in the tweet).  They say that two is enough, I'm wondering if there is a plan to give each BE-3U two nozzles to allow higher thrust.

* maybe less nozzles, but expander cycles have hard limits for how much thrust/(nozzle+combustion chamber) and it can't be that higher than RL-10.

True enough, the wiki hasn't updated to the expander cycle statement, presumably.

My point was that the Be-3U is on track to basically be an RL-10, but hopefully not as absurdly overpriced.

[sh1pman]

2 hours ago, tater said:

True enough, the wiki hasn't updated to the expander cycle statement, presumably.

My point was that the Be-3U is on track to basically be an RL-10, but hopefully not as absurdly overpriced.

How do they compare Isp-wise?

[tater]

23 minutes ago, sh1pman said:

How do they compare Isp-wise?

No data from Blue, but I think this buys maybe 30s Isp.

[sevenperforce]

25 minutes ago, sh1pman said:

How do they compare Isp-wise?

Well, that's the million-dollar question. Or the 38-million-dollar question, in this case.

The RL-10 is an expander-cycle engine, which means that it uses the high thermal coefficient of its liquid-hydrogen fuel, in an expansion chamber, to drive a turbopump. It's more efficient than a full-flow staged-combustion engine and wastes no propellant at all.

The current BE-3 is a "combustion tapoff" engine, which vents a small amount of hydrogen-rich steam from the combustion chamber to run the turbopump. It's about as efficient as a gas-generator cycle but has a better TWR.

If the BE-3U is being converted to expander cycle, then we could conceivably see an engine every bit as efficient as the RL-10, for a fraction of the price. 

3 hours ago, wumpus said:

The BE-3 wiki still says "490 kN thrust', while the RL-10 says "110 kN thrust".  The only way you are getting an expander cycle engine up to 490kN is with at least* 4 nozzles (and we see only one in the tweet).  They say that two is enough, I'm wondering if there is a plan to give each BE-3U two nozzles to allow higher thrust.

* maybe less nozzles, but expander cycles have hard limits for how much thrust/(nozzle+combustion chamber) and it can't be that higher than RL-10.

The geometric limit to a full-flow expander-cycle engine is about 270% the thrust of an RL-10.

However, it's possible to run only a portion of the hydrogen through the nozzle (about 72%, in this case), use that on the same expansion loop originally used by tap-off to run the same turbopump, and let the remaining 28% run straight from the tanks into the chamber. Don't know if it would have enough power to run, but it's a possibility. It may be that such a "bypass-expander-cycle" engine relies on a larger engine bell and thus would not work for the atmospheric variant.

[wumpus]

2 hours ago, sevenperforce said:

The geometric limit to a full-flow expander-cycle engine is about 270% the thrust of an RL-10.

I don't doubt that, but it must be easier to build a second nozzle than to try to wring out more than twice as much power from hydrogen expansion.  Especially if you want to try to relight it (I suspect much of RL-10's cost is needing two sets of turbopumps just to get it started).  Russian designs use multiple nozzles for kerolox rockets and this seems to help with other issues as well.

[sevenperforce]

14 hours ago, wumpus said:

I don't doubt that, but it must be easier to build a second nozzle than to try to wring out more than twice as much power from hydrogen expansion.  Especially if you want to try to relight it (I suspect much of RL-10's cost is needing two sets of turbopumps just to get it started).  Russian designs use multiple nozzles for kerolox rockets and this seems to help with other issues as well.

I don't see that there would be any significant difference in the engineering challenge of designing a 100-kN-class expander nozzle and a 300-kN-class expander nozzle. Certainly wouldn't be worth redesigning the entire combustion chamber.

[tater]

 

[tater]

 

[sh1pman]

Was about to post that^

I wonder how well the NG competes with FH for beyond-LEO destinations. Hydrolox upper stage gives a huge advantage there.

[Ultimate Steve]

11 minutes ago, sh1pman said:

Was about to post that^

I wonder how well the NG competes with FH for beyond-LEO destinations. Hydrolox upper stage gives a huge advantage there.

Reusable NG might beat expendable FH by a bit, but expendable NG will definitely beat expendable FH unless the design of NG has changed tremendously since we've last had an update.

[tater]

 

[CatastrophicFailure]

 

Now, the question is, can they come up with a suitable and quirky name?

[Canopus]

55 minutes ago, CatastrophicFailure said:

Now, the question is, can they come up with a suitable and quirky name?

I hope they don't follow SpaceX with their naming Scheme.

Edited September 25, 2018 by Canopus

[insert_name]

49 minutes ago, CatastrophicFailure said:

Now, the question is, can they come up with a suitable and quirky name?

maybe new hornet, after the carrier that recovered a lot of the manned space capsules in the 60s?

[sh1pman]

1 hour ago, CatastrophicFailure said:

 

Now, the question is, can they come up with a suitable and quirky name?

“New OCISLY”

[Mad Rocket Scientist]

9 hours ago, CatastrophicFailure said:

Now, the question is, can they come up with a suitable and quirky name?

 

8 hours ago, Canopus said:

I hope they don't follow SpaceX with their naming Scheme.

Mr. Steven was not actually SpaceX's pick. Just normal crazy boat naming.

[Ultimate Steve]

10 hours ago, Mad Rocket Scientist said:

 

Mr. Steven was not actually SpaceX's pick. Just normal crazy boat naming.

I, for one, am glad that they named a boat after me.

Edited September 26, 2018 by Ultimate Steve

[mikegarrison]

According to the shipping article, the former STENA ship will be used to "transport rocket components". Considering it is a freighter, that would be understandable. I saw nothing there about being used as a landing platform. But the other article said it would be the landing platform. Where did that info come from?

[Additional info: on Burghardt's twitter he later said, "we don't have an official confirmation that Stena Freighter will be the recovery ship."]

Edited September 26, 2018 by mikegarrison