Talk:Merlin (rocket engine)

Fastrac

Is it true that the Merlin engine uses the same technology as NASA's (cancelled) Fastrac project? --NeuronExMachina 03:19, 5 Aug 2004 (UTC)

I don't know all of the details, but here's an article on Fastrac and one on TRW's Low Cost Pintle Engine (LCPE) for future reference. Both engines were designed at roughly the same time and Tom Mueller, now VP of Propulsion at SpaceX, was on (led?) the LCPE team for TRW. Because of this, I would expect that Merlin would look more like LCPE than Fastrac. The merlin engine has roughly the same thrust as Fastrac and about 1/10 the thrust of LCPE. I guess I wouldn't be surprised to see a SpaceX design that looks an awful lot like LCPE coming out in the future.Dschmelzer 17:42, 5 Aug 2004 (UTC)

There's some discussion on the a-rocket mailing list that indicates SpaceX may have associated the turbopump with the Fastrac design, but that it's actually a clean sheet design. This level of detail is well beyond my expertise though. Dschmelzer 19:27, 23 Aug 2004 (UTC)

"Is it true that the Merlin engine uses the same technology as NASA's (cancelled) Fastrac project?" No. The Fastrac turbopump is a different turbopump in its entirety. The Spacex turbopump was developed by Barber-Nichols under a clean sheet design program and the designs although being similar are entirely different. There is a picture of the FASTRAC turbopump here: http://www.gkllc.com/lit/gk-authored/AIAA-2007-5537_Hydrogen_Peroxide-Optimal_for_Turbomachinery_and_Power_Applications.pdf (page 15 section V)and here is a picture of the Merlin Turbopump here: http://images.spaceref.com/news/2003/05.09.03.spacex.merlin_turbopump.jpg

Article name

Should this article be at Merlin (rocket engine), sort of like Kestrel (rocket engine)? --NeuronExMachina 07:42, 18 Aug 2004 (UTC)

Done --Duk 20:19, 4 October 2005 (UTC)

Propose merger

I'd like to propose that Merlin 1B and Merlin 2 be merged into Merlin (rocket engine). The two child articles are very brief stubs, and not much outside information is available about the separate models. These models can adequately be covered as sections for the main Merlin article. If enough detail about one model becomes available in the future then it can be broken out. At this point the breakout just results in unnecessary clicking. --StuffOfInterest 17:21, 17 November 2006 (UTC)

Sounds good --Duk 17:29, 17 November 2006 (UTC)

Done. With the possible launch in a couple of days it seemed to prudent to get the cleanup done before the likely visitors show up. --StuffOfInterest 00:22, 18 January 2007 (UTC)

Graphic of Merlin 1C available for Wikipedia?

This article could really use a good photo or diagram of a version 1C engine. There are some good ones here: "http://www.spacex.com/updates.php". SpaceX. 2007-12-10. http://www.spacex.com/updates.php. Retrieved 2008-06-12. 

I am not familiar enough with Wikipedia image guidelines to know if we can use one of these, and under what size/limitation conditions, so will leave that for other more graphic-aware Wikipedians. N2e (talk) 02:32, 13 June 2008 (UTC)

Since the article has a photo now, and it's a Creative Commons image, I have disabled the {{Reqphoto}} tag. If there are additional/better images needed, feel free to undo my actions. ^Avicenna_sis @ 05:06, 31 March 2010 (UTC)

Yes, this article requires a replacement for the years-obsolete Merlin 1A engine diagram used in the infobox. This should be a diagram or illustration rather than a photo. --IanOsgood (talk) 21:39, 30 March 2011 (UTC)

BFE = 27 Merlin 1C engines?

The following exchange is from an interview at http://www.washingtonpost.com/wp-dyn/content/discussion/2008/09/24/DI2008092402502.html

Urbana, Ill.: Right now you have two rockets based on the same first-stage engine (Merlin). To launch Falcon 9 Heavy, you'll need 27 of those engines to fire simultaneously. Do you have any plans to develop a larger engine in the future so that such clustering is not necessary?

Elon Musk: Yeah, I think there is an argument for a really really big Falcon engine or BFE, as we call it :)

That would be equal or greater to the thrust of 27 Merlin 1C engines. Would be exciting to see that fire! On the other hand, lots of small engines can give very high reliability. Google uses lots of small PC computers for their search service and it has never ever gone down.

91.107.42.12 (talk) 13:17, 28 September 2008 (UTC)

Rocket engine infobox

I'm not trying to be picky, but I feel the overall layout and content was better before the infobox was added. I don't really think the infobox is ready for primetime; it's used in only one other rocket engine article that I can see. And the content was changed; "sea level thrust" was changed to simply "thrust", and "vacuum thrust" became "thrust at altitude". I think the infobox itself needs more work before it should be added to the article, or at least before it is used to replace in-article information. Djd sd (talk) 09:35, 30 September 2008 (UTC)

I've done some work on the infobox; resize image instead of 'thumb' image, added thrust(Vac) and thrust(SL). --Duk 15:12, 30 September 2008 (UTC)

Merlin 2

Anyone know why the section on Merlin 2 was removed? Djd sd (talk) 04:39, 1 October 2008 (UTC)

I removed it because other than some vague hints three years ago, there aren't any sources for it. I just commented it out, looks like someone else deleted it. --Duk 05:20, 1 October 2008 (UTC)

Sounds like a good enough reason. With all the recent changes, I was having trouble figuring out who was doing what. Djd sd (talk) 07:25, 1 October 2008 (UTC)

Merlin Vacuum

Just received from SpaceX newsletter

New Merlin Vacuum engine demonstrates highest efficiency for an American hydrocarbon rocket engine
McGregor, TX – (March 09, 2009) – Space Exploration Technologies Corp (SpaceX) successfully conducted a full mission duration firing of its new
Merlin Vacuum engine on March 7, at SpaceX's Test Facility in McGregor, Texas. The engine fired for a full six minutes, consuming 100,000 pounds
of liquid oxygen and rocket grade kerosene propellant.
The new engine, which powers the upper stage of SpaceX's Falcon 9 launch vehicle, demonstrated a vacuum specific impulse of 342 seconds – the
highest efficiency ever for an American hydrocarbon rocket engine. Thrust was measured at approximately 92,500 lb of force in vacuum conditions
and the engine remained thermally stable over the entire run.

Mchl (talk) 21:43, 10 March 2009 (UTC)

Yes, I just saw this also. A serviceable link for the information is spacex.com/press.php?page=20090310. N2e (talk) 22:25, 10 March 2009 (UTC)

Moved from article page: Xorsprite (talk) 03:31, 23 March 2009 (UTC) This figure disagrees with the "Engine specifications" section as published here http://en.wikipedia.org/wiki/Merlin_(rocket_engine)#Merlin_1C. Also this specific impulse of 342 s in a vacume does sound too high from what I've been reading making it even more efficient than the Soviet NK-33 (one of the highest specific impulse values of any engine for this type of fuel - LOX + Kerosene - and the Russians are still the world leaders) on the page http://en.wikipedia.org/wiki/Specific_impulse under "Figures for real engines" —Preceding unsigned comment added by Aremisasling (talk • contribs)

You are comparing apples to oranges. NK-33 is a first stage engine, so it is thrust optimized, not ISP optimized. The nozzles are shaped differently for one, the pumps are likely tuned differently for another. The Soyuz 2 upper stage engine RD-0124, also LOX/Kerosene staged combustion, has a vacuum specific impulse of 359 seconds. The Zenit upper stage RD-58M is a LOX/Kerosene engine using a gas generator cycle with a specific impulse of 353 seconds. Merlin Vacuum can also throttle thrust between 60-100% which saves fuel. Quasarstrider (talk) 16:24, 13 February 2010 (UTC)

First successful launch to orbit has raised "importance=mid"
--Mkouklis (talk) 14:10, 6 June 2010 (UTC)

With the Merlin Vacuum engine so much in the space news over the two days prior to the successful launch of Falcon 9 Dragon C1, due to the cracks in the Mvac nozzle and, ultimately, the decision to trim four feet of the nozzle off for the Dragon C1 launch two days after the cracks were discovered, I think the article would really benefit from a photo of the Mvac engine and nozzle, or maybe even a diagram comparing the Mvac with the standard Merlin 1C. N2e (talk) 15:53, 9 December 2010 (UTC)

Merlin Injector

Is the Merlin still a Pintle injector?

I thought the Merlin 1 and 1A were pintles but they went to a Showerhead injector on the 1B, and there after.

Granted the press info is just a little confusing, but, I thought i would ask —Preceding unsigned comment added by 71.178.199.89 (talk) 22:04, 27 January 2011 (UTC)

Potential table for comparison of engine version specs

I believe it might be time to consider expanding the Merlin 1C Engine specifications section of the article to become a more general Specifications section that would provide an historical comparison of the various important versions of the engine. (this Talk section is independent of who would do the work of creating such a table; just interested for now to see if other editors thinks such a table a good idea).

It would seem that the first flight Merlin, the Merlin 1A, as well as the now-flown Merlin 1C and Merlin Vacuum would be included, along with perhaps the under-development-but-not-yet-flown Merlin 1D. What do others think about this? N2e (talk) 16:11, 6 April 2011 (UTC)

Merlin 1D details

Quite a bit of new info on the Merlin 1D enhancements, much not already in the article, is in this press article published January 11th: [1] <ref name=nsdc20120111> {{cite news |last=Bergin|first=Chris |title=SpaceX to begin testing on Reusable Falcon 9 technology this year |url=http://www.nasaspaceflight.com/2012/01/spacex-testing-reusable-falcon-9-technology-this-year/ |accessdate=2012-01-13 |newspaper=NASA Spaceflight.com |date=2012-01-11}} </ref> Enjoy. N2e (talk) 05:43, 12 January 2012 (UTC)