tag:blogger.com,1999:blog-8628325.post113995089214212200..comments2024-03-15T05:59:53.929-07:00Comments on Ambivalent Engineer: Why Merlin 2?Ambivalent Engineerhttp://www.blogger.com/profile/16491915174390340818noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-8628325.post-79446813921977650312006-11-17T10:36:00.000-08:002006-11-17T10:36:00.000-08:00This is in response to the last, detailed, informa...This is in response to the last, detailed, informative comment.<br /><br />You're right. I goofed. I had thought that the RD-170 was not an actively utilized engine, but of course it is used in the SeaLaunch and Zenit rockets. That puts a much larger upper bound on the thrust of Merlin 2. You suggest a 5,000 kN thrust instead of the 4,000 kN thrust that I supposed. That doesn't really change the lift options I was suggesting.<br /><br />You point out a payload that I hadn't thought about: the heavy satellite to GEO. A 5,000 kN Merlin 2 would make Falcon 9S9 able to lift more to GEO, but it can already lift a reasonable amount there, and a lot of those launches are currently double satellite launches. I don't see a large increase in possible payloads here.Ambivalent Engineerhttps://www.blogger.com/profile/16491915174390340818noreply@blogger.comtag:blogger.com,1999:blog-8628325.post-1152389300817073242006-07-08T13:08:00.000-07:002006-07-08T13:08:00.000-07:00Largest active engine is the RD-170 at 1.7 million...Largest active engine is the RD-170 at 1.7 million pounds thrust at 4 chambers. For SpaceX to have the largest single-chamber thruster that is not the F-1, then Merlin 2 should have greater thrust than RS-68, but less thrust than F-1. Using the RD-180 at 850,000 lbs thrust as the upper limit for Merlin 2 thrust is probably not correct. Musk's public comments probably indicate they are thinking of Merlin 2 as something between the 650,000 lbs of RS-68 and the 1.5 million lbs of F-1.<BR/><BR/>The TR107 was a pintle-injector LOX/RP engine with thrust rated at 1.1 million pounds. Northrop received about $40 million in NASA contracts up to FY05 to develop this engine for the now cancelled SLI. Northrop maybe thought that SpaceX had borrowed their Merlin 1 engine design from the TR107 engine.<BR/><BR/>I am just guessing, but SpaceX could continue the design work of the TR107, and call it the Merlin 2. This Merlin 2 would look very similar to both the Merlin 1 and the TR107, and they could ask for NASA/DOD contracts to develop it.<BR/><BR/>A Merlin 2 with 1.1 million lbs thrust, like the TR107, would give 3.6 meter diameter Falcon 9 vehicle a 33,000 lbs to LEO performance - similiar to Sea Launch Zenit or proposed Soyuz 3. They would price this between the $35 million Falcon 9 with 5 meter fairing and the $51 million version that does 33,000 lbs to LEO. This rocket would eliminate the need to learn parallel staging on the S5 version of the Falcon 9. There is probably not a large market for the 50,000 lb payload version of the Falcon 9 triple, but it looks nice in brochures and Air Force/NRO EELV customer briefings.<BR/><BR/>The 1.1 million lb thrust Merlin 2, similiar to the TR107, could be later integrated into a 7.2 meter or 8 meter diameter vehicle that offers 132,000 lbs to 330,000 lbs payload to LEO, with engine out capability on a 5-engine or 9-engine first-stage. For this new rocket, SpaceX would have to learn how to double the diameter of their Falcon 9 vehicle, to 7.2 meters or greater, just as they doubled the diameter of the Falcon 1 to become the Falcon 9. If you re-evaluate the Saturn V vehicle with a LOX/RP second-stage powered by a Merlin 2 (or TR107), an 8-meter diameter, a 5 Merlin 2 engine first-stage (i.e. 5.5 million lbs thrust), and no thrird-stage then you probably get a payload number around 176,000 lbs (i.e. 80 Metric tons). <BR/><BR/>Who is the customer? What is the market? The customer could just be a development contract for Merlin-2 engine development. For payloads, the customer for a 33,000 lb version of Falcon 9 is the same customer-base for Sea Launch and Ariane V - commercial launch of 10,000 lb class satellites to GEO, which the proposed Falcon 9 single can't do right now. The customer for a 60 metric ton to 130 metric ton launcher is the Air Force or anyone wanting to fly to the Moon or Mars. Space Adventures will fly a minimum of 2 paying passengers to the moon for $100 million each, which is a minimum of $200 million. I would think that many countries would pay $200 million to fly around the Moon, Venus, or Mars. I would guess that SpaceX could find a way to profitably launch a much more capable payload than Space Adventures is planning for well under $200 million if SpaceX ad this vehicle.<BR/><BR/>The cost of Merlin 2 engine development should be under $100 million, because SpaceX has the TR107 as a baseline. If it costs SpaceX $200 million total to develop an 80 metric ton payload vehicle, and a Merlin 2 engine to propel it, SpaceX would make a $50 million profit if the U.S. Air Force gave SpaceX a $250 million demo launch contract similar to the $250 million launch contract they gave to Boeing for the partially successful Delta IV Heavy launch demo (with only 25 ton capability). If SpaceX gets NASA or the Air Force to pay for the development on cost-plus contracts, then the economics are really in their favor.<BR/><BR/>If the Merlin 2 is the TR107, then the risk to return economics are not as bad as they might initially appear. For an investment of $100 million to $200 million in the Merlin 2, SpaceX might double their competitveness and the market of payloads that they are qualified to launch.<BR/><BR/>What do you think?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8628325.post-1139997588845179262006-02-15T01:59:00.000-08:002006-02-15T01:59:00.000-08:00I would not worry too much about this. Obviously t...I would not worry too much about this. Obviously the merlin 2 is a long term project. <BR/><BR/>For the text two years, the spacex engine design team will be very busy designing and building a regeneratively cooled version of the merlin 1, a high expansion ratio version of the merlin 1 that will double as a heat shield (remember the falcon 9 upper stage is supposed to be reusable), and maybe trying to increase the combustion efficiency of the merlin 1.<BR/><BR/>Only when all this is done will they start seriously designing the merlin 2. And there is no alternative to that since elon needs to keep his engine design team together. <BR/><BR/>An experienced engine design team is a very valuable asset if he wants to do an IPO. And big plans for the future are also quite nice for an IPO.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8628325.post-1139969277471729382006-02-14T18:07:00.000-08:002006-02-14T18:07:00.000-08:00rd-170 and rd-180, not rs :)rd-170 and rd-180, not rs :)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8628325.post-1139968018225269892006-02-14T17:46:00.000-08:002006-02-14T17:46:00.000-08:00Useful, interesting post. I view the Merlin 2 as ...Useful, interesting post. I view the Merlin 2 as something that can take in several of your scenarios. The goal would be to remove all of the remaining excuses for not using SpaceX's rockets.<BR/><BR/>Besides, Musk now has an experienced engine development team assembled at considerable cost and care, so why not use it? Would he be able to avoid parrallel staging altogether on the Falcon 9, if engine development is successful and on time?<BR/><BR/>Dan SchmelzerAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-8628325.post-1139958106357009532006-02-14T15:01:00.000-08:002006-02-14T15:01:00.000-08:00it would almost be cheaper for elon to pick restar...it would almost be cheaper for elon to pick restart the rd-270. not very green, but if you are launching from an atoll, nobody is there to breathe the fumes,<BR/><BR/>only kidding.Anonymousnoreply@blogger.com