Author Topic: SpaceX: Merlin 1D thread  (Read 200195 times)

Offline meekGee

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Re: SpaceX: Merlin 1D thread
« Reply #630 on: 03/23/2013 05:31 PM »
That's like saying they put parachutes in the first F9 so why not keep putting them in all other vehicles as well, to avoid multiple configurations. Recovery systems had logic as well. 1st stage guidance and 2nd stage guidance shouldn't really be linked in a way that it counts as an integration problem if you *remove* 1st stage guidance when you don't need it. It's supposed to kick in only after staging and be completely inactive until then. At least that's what the customers would like, I'd think.

And actually, looking back about a couple of month, we had a fierce argument here where I argued that they should standardize the pitch-over/restart/avionics hardware on all 1.1s, to facilitate testing.

As always it was the case of "you don't know anything", "cool-aid", and "customers won't allow it" - since they hate configuration changes.

So we had a trade-off: SpaceX wants to experiment with reentry, customers want a stable configuration.

Now that we know (btw, was it ever corroborated?  I think it is still a single-source bit of knowledge) that the first flight will already carry all of the hardware, there's no longer a trade-off - everyone wants the same thing.

As for the first stage avionics, I wouldn't make them "turn on" after separation.  If they're not driving the combined stack, I'd at least make them fully awake, keeping track of all the data, and in independent communication with the ground - again, to get as much development done as early as possible, which is what SpaceX has always been doing.

Offline joek

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Re: SpaceX: Merlin 1D thread
« Reply #631 on: 03/23/2013 05:49 PM »
So we had a trade-off: SpaceX wants to experiment with reentry, customers want a stable configuration.

Customers want to reduce risk.  A stable configuration is one way; greater margins is another way.

Offline cambrianera

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Re: SpaceX: Merlin 1D thread
« Reply #632 on: 03/23/2013 05:52 PM »
Off topic.
Please go on the right topic: http://forum.nasaspaceflight.com/index.php?topic=21923.0

Offline russianhalo117

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Re: SpaceX: Merlin 1D thread
« Reply #633 on: 03/24/2013 12:47 AM »
Thank you Chris for oversight on the thread. I lost my reading glasses a few days ago and am having difficulties with reading and writing.

Maybe a possible 1E will come out of the long wait of the 1D?

Even the "Is  Falcon 1E dead?" thread is dead.  (No, he's just resting.  Dead!  Dead, I tell you!)

There must be a bunch of Merlin 1C's around and they have the F1 launch erector and pad available from Kwaj which they could set up at CCAFS or VAFB, but SpaceX said they would not sell any Falcon 1 rockets.  I was disappointed.  They "built it" but "they did not come".   The Merlin 1D just makes it less likely. SpaceX is not going to the effort of creating a whole new rocket that is not on their main path.
F1 programme Merlin-1C's were transferred to the F9 programme quite a while ago, so the answer to the beginning of post is a confirmed no.

Offline llanitedave

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Re: SpaceX: Merlin 1D thread
« Reply #634 on: 03/24/2013 01:35 AM »
Thank you Chris for oversight on the thread. I lost my reading glasses a few days ago and am having difficulties with reading and writing.

Maybe a possible 1E will come out of the long wait of the 1D?

Even the "Is  Falcon 1E dead?" thread is dead.  (No, he's just resting.  Dead!  Dead, I tell you!)

There must be a bunch of Merlin 1C's around and they have the F1 launch erector and pad available from Kwaj which they could set up at CCAFS or VAFB, but SpaceX said they would not sell any Falcon 1 rockets.  I was disappointed.  They "built it" but "they did not come".   The Merlin 1D just makes it less likely. SpaceX is not going to the effort of creating a whole new rocket that is not on their main path.
F1 programme Merlin-1C's were transferred to the F9 programme quite a while ago, so the answer to the beginning of post is a confirmed no.

I don't think the question was about the Falcon 1E, but about about a possible Merlin 1E, a hypothetical follow-on to the Merlin 1D.

I don't know if they're going to be happy with that engine and make it mainstream for a while, or if they have a continuous development program going on with it.

Offline spectre9

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Re: SpaceX: Merlin 1D thread
« Reply #635 on: 03/24/2013 01:40 AM »
Has a Merlin 1D ever failed (exploded) in testing?

If one did would SpaceX disclose it?


Offline meekGee

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Re: SpaceX: Merlin 1D thread
« Reply #636 on: 03/24/2013 02:18 AM »
Has a Merlin 1D ever failed (exploded) in testing?

If one did would SpaceX disclose it?
"If engines are not exploding, you are not testing hard enough" ?

Offline 8900

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Re: SpaceX: Merlin 1D thread
« Reply #637 on: 03/24/2013 02:50 AM »
Thank you Chris for oversight on the thread. I lost my reading glasses a few days ago and am having difficulties with reading and writing.

Maybe a possible 1E will come out of the long wait of the 1D?

Even the "Is  Falcon 1E dead?" thread is dead.  (No, he's just resting.  Dead!  Dead, I tell you!)

There must be a bunch of Merlin 1C's around and they have the F1 launch erector and pad available from Kwaj which they could set up at CCAFS or VAFB, but SpaceX said they would not sell any Falcon 1 rockets.  I was disappointed.  They "built it" but "they did not come".   The Merlin 1D just makes it less likely. SpaceX is not going to the effort of creating a whole new rocket that is not on their main path.
F1 programme Merlin-1C's were transferred to the F9 programme quite a while ago, so the answer to the beginning of post is a confirmed no.

I don't think the question was about the Falcon 1E, but about about a possible Merlin 1E, a hypothetical follow-on to the Merlin 1D.

I don't know if they're going to be happy with that engine and make it mainstream for a while, or if they have a continuous development program going on with it.
As far as I know there is no plan of (Merlin) 1E, no one has talked about it so I assume it doesn't exist
There are talks of Elon abut Merlin 2 (large engine, one is enough to power the F9 first stage but the rocket will also lose engine out capability) and Raptor cryogenic upper stage, maybe what he means is Merlin 2 instead of 1E

Offline Okie_Steve

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Re: SpaceX: Merlin 1D thread
« Reply #638 on: 03/24/2013 02:57 AM »
"If engines are not exploding, you are not testing hard enough" ?
Yep, failure tells you where the boundaries really are as opposed to where you *think* they are. I don't expect Spacex to tell us where those boundaries are either since current appearances to the contrary they might decide to iterate to a Merlin 1E at some point if it looks worth while enough. In any case they don't want to give away any competitive advantages. Which comes back to the question of how far might it be possible to push a kero-lox engine like the Merlin 1D in a do-or-die situation? Anyone have any guess based on prior art? If the answer is 1-2% vs 10-20% the number of useful scenerios changes greatly.

Offline meekGee

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Re: SpaceX: Merlin 1D thread
« Reply #639 on: 03/24/2013 03:05 AM »
Regarding a hypothetical Merlin 1E, maybe someone remembers - were there any rumors about the 1D before it was revealed?  If yes, how long before?

I wouldn't be surprised if they iterated again, since a) re-usability is coming and they want engines to last many cycles and b) they will soon start having engines recovered after flight, and there will a lot to learn from them towards future iterations.

EDIT: D, not E.
« Last Edit: 03/24/2013 07:14 AM by meekGee »

Offline Lars_J

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Re: SpaceX: Merlin 1D thread
« Reply #640 on: 03/24/2013 05:40 AM »
Regarding a hypothetical Merlin 1E, maybe someone remembers - were there any rumors about it before it was revealed?  If yes, how long before?

What? There have been no 1E rumors.

Offline meekGee

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Re: SpaceX: Merlin 1D thread
« Reply #641 on: 03/24/2013 07:14 AM »
Sorry - see Edit above...

Offline mlindner

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Re: SpaceX: Merlin 1D thread
« Reply #642 on: 03/24/2013 07:54 AM »
I'm not sure how all this discussion about a non-existant Merlin 1E came about... There have been _zero_ rumors about a Merlin 1E so let's stop talking about something that we have heard _nothing_ about it even existing. This is even worse than talking about the MCT which we barely only know the acronym for (but not what the letters stand for).

More so it look like Merlin 2 has been abandoned as well, unlikely to happen. Raptor is no longer a cryogenic upper stage, but now a methane stage-agnostic high thrust engine. (It honestly appears the concepts for Merlin 2 (higher thrust Merlin 1) and Raptor (high ISP upper stage) have been combined into one engine under the name Raptor.) SpaceX obviously changes even what names refer to over time, so there is no point on latching on to a name that doesn't even exist yet (Merlin 1E)...
« Last Edit: 03/24/2013 07:57 AM by mlindner »

Offline spectre9

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Re: SpaceX: Merlin 1D thread
« Reply #643 on: 03/24/2013 08:22 AM »
Rocketdyne engines have been tested to failure and that information has been made public.

SpaceX can do what they like I guess. Sometimes the secrecy is a bit annoying.

Offline mlindner

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Re: SpaceX: Merlin 1D thread
« Reply #644 on: 03/24/2013 08:30 AM »
Rocketdyne engines have been tested to failure and that information has been made public.

SpaceX can do what they like I guess. Sometimes the secrecy is a bit annoying.

I asked a friend who interned at SpaceX McGregor last summer about if he had heard of them shrapnel testing any engines by testing them till they blew. He hadn't. That doesn't confirm or deny though, just a data point.
« Last Edit: 03/24/2013 08:31 AM by mlindner »

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