Remember who asked for the raptor derived US engine to begin with. What if any sort of launch profile might they be interested in that even the super duper M1D of the future might not be able to hack?
Remember who asked for the raptor derived US engine to begin with.
Quote from: Okie_Steve on 05/16/2017 02:24 am Remember who asked for the raptor derived US engine to begin with. Take a look at the SpaceX Mars presentation, then look at what NASA says about Mars, then checkout the Boeing or Lockmart websites. Outside of the SpaceX fanbase, the rest of the world (including the investment community) does not believe ITS is going to happen any time soon. ...
Landing F9 S1 repeatedly is great, but they must go further:
I think the odds of seeing a RUS is significantly reduced after the Tom Mueller interview, he gave no hints this is happening, instead he talked about the Mars rocket, hundreds of tons to orbit, etc. Also when he talked about 2nd stage reuse, it sounds like the stage is still performance challenged, which would not be the case for a big RUS.
from @Painkiller606@elonmusk How will Raptor-vac engine bell be cooled? Will radiative cooling work with other engine bells surrounding it?
from @elonmusk@Painkiller606Will be full regen cooled all the way out to the 3 meter (10 ft) nozzle diameter. Heat flux is nuts & radiative view factor is low.
So, if this test Raptor is made into an engine, would it be about the same size as the Merlin V? And if so, could the existing size upper stage to increase ISP enough to get larger payloads into orbit off F9 and FH? The existing upper stage is small enough to be filled by tanker LNG tractor trailer trucks it seems. My company had one and it was used if there were low pressure areas of our natural gas distribution system during extremely cold weather. It could supply a town of 25,000 for about a month with one truck load of LNG (residential/small commercial only, not industrial). So 2 or 3 of these tractor trailers could fill one upper stage.
Quote from: spacenut on 06/21/2017 05:04 pmSo, if this test Raptor is made into an engine, would it be about the same size as the Merlin V? And if so, could the existing size upper stage to increase ISP enough to get larger payloads into orbit off F9 and FH? The existing upper stage is small enough to be filled by tanker LNG tractor trailer trucks it seems. My company had one and it was used if there were low pressure areas of our natural gas distribution system during extremely cold weather. It could supply a town of 25,000 for about a month with one truck load of LNG (residential/small commercial only, not industrial). So 2 or 3 of these tractor trailers could fill one upper stage. Hypothetically (since I doubt they would just convert it) it would get less performance with the same volume upper stage. Lower density methane takes up more space and therefore you can't load nearly as much propellant. Same reason ULA's Vulcan has to be a 5+m first stage instead of keeping the Atlas tankage. There are some gains due to a lighter overall weight but that makes the first stage separation velocity even higher which cant be great for recovery.
So, would it help at all, OR, would you have to make the stage wider, or longer to achieve upgraded capabilities?
Could a 1.5 stage to orbit using two Falcon Heavy boosters and a core (orbital stage) powered by a single vacuum optimized Merlin 3MN engine. The core could be derived from an expendable falcon heavy core.I'm very sceptical about upperstage reusability, so the core will be expendable.If required an small in orbit maneuvering stage (Hypergolic Draco, or LOx-Methane) could be added.Could this work? What will be it's performance? And is it a good idea?I think for a Falcon 9 upper-stage a Raptor 1MN would be required. I do like the idea.A methane merlin (Merlin 1D.M / 1DV.m) could be an intermediate development before the FFSC Raptor 3MN.
Quote from: Rik ISS-fan on 06/22/2017 08:06 amCould a 1.5 stage to orbit using two Falcon Heavy boosters and a core (orbital stage) powered by a single vacuum optimized Merlin 3MN engine. The core could be derived from an expendable falcon heavy core.I'm very sceptical about upperstage reusability, so the core will be expendable.If required an small in orbit maneuvering stage (Hypergolic Draco, or LOx-Methane) could be added.Could this work? What will be it's performance? And is it a good idea?I think for a Falcon 9 upper-stage a Raptor 1MN would be required. I do like the idea.A methane merlin (Merlin 1D.M / 1DV.m) could be an intermediate development before the FFSC Raptor 3MN.What is Merlin 3MN? Raptor 1MN? Raptor 3MN?