Hi, Long time lurker on this forum. I am not in the industry, just a space flight enthusiast, so I make no claim to knowing if this is possible. Any way, since the Merlin 1D has been touted as having this incredible boost in thrust over Merlin 1c, couldn't they remove some engines from F9 when launching smaller payloads? Thus lowering cost?
Merlin 1D only offers a 12% increase in thrust from the previously announced plans for Merlin 1C (140K versus 125K), so no engine reduction is possible for the Falcon 9 Block 2 currently cataloged in the SpaceX User's Guide. It might be possible to launch a Block 1 Falcon 9 using only seven Merlin 1D engines, but SpaceX is not publicly offering Block 1 as a "buy" option. - Ed Kyle
Quote from: edkyle99 on 04/21/2011 07:21 pmMerlin 1D only offers a 12% increase in thrust from the previously announced plans for Merlin 1C (140K versus 125K), so no engine reduction is possible for the Falcon 9 Block 2 currently cataloged in the SpaceX User's Guide. It might be possible to launch a Block 1 Falcon 9 using only seven Merlin 1D engines, but SpaceX is not publicly offering Block 1 as a "buy" option. - Ed KyleThat doesn't sound right. Merlin 1-C is 95 klbf AFAIK. Merlin 1-D is 140 klbf as you say. (Up from 135 klbf in a January projection) 9*95=855 5*140=700 so a Falcon 5(1D) would have have only 82% of the thrust of the Falcon 9(1C).On the other hand, The Falcon 9 will require significant structural redesign to accommodate the higher thrust. This may be part of what we are seeing in the longer stages of the Falcon Heavy. If they could grow the Merlin 1-D to 165-170 klbf, about a 20% additional increase, they would have a proven structure and launch facility and a less expensive rocket with existing tooling. Would it be worth it? I wouldn't know.
Then there remains Shotwell's comment about instability.