Quote from: nacnud on 03/29/2017 01:14 pmThere isn't going to be a reusable second stageNo. But for a few years SX certainly thought they could make it work. Then they discovered it couldn't be made to work at a price they wanted to pay, although it's still unclear why. My instinct is F9 is going to be around for some time to come, but will only partly be reusable.
There isn't going to be a reusable second stage
We shouldn't deal too much in certainties when it comes to SpaceX, especially when we are dealing with things that are technically possible - and a methane-fueled upper stage is. Last year, the suggestion that SpaceX is planing a circumlunar mission would have been laughed at, and serious people would have stated clearly and in all their seriousness that SpaceX does not deal with that space tourism crazy, isn't interested in the Moon, and wants to stay laser-focused on Mars. And yet, here we are...
I fully agree that right now, a reusable upper stage is not on the top of their priority list, there are many other things up there. Nevertheless, if the prices come down further with the introduction of the New Glenn, and SpaceX thus needs to make that second stage reusable (perhaps even integrate it with the payload fairing to get a fully reusable "upper stage satellite delivery vehicle") to stay competitive, they will do it (unless it would be cheaper to develop and operate an ITS-derived solution).
Quote from: Bynaus on 03/30/2017 12:52 pmWe shouldn't deal too much in certainties when it comes to SpaceX, especially when we are dealing with things that are technically possible - and a methane-fueled upper stage is. Last year, the suggestion that SpaceX is planing a circumlunar mission would have been laughed at, and serious people would have stated clearly and in all their seriousness that SpaceX does not deal with that space tourism crazy, isn't interested in the Moon, and wants to stay laser-focused on Mars. And yet, here we are... SX is in the transport business. People approached SX for this. If they didn't I doubt SX would care. Quote from: Bynaus I fully agree that right now, a reusable upper stage is not on the top of their priority list, there are many other things up there. Nevertheless, if the prices come down further with the introduction of the New Glenn, and SpaceX thus needs to make that second stage reusable (perhaps even integrate it with the payload fairing to get a fully reusable "upper stage satellite delivery vehicle") to stay competitive, they will do it (unless it would be cheaper to develop and operate an ITS-derived solution).When the CEO and Chief Designer says no reusable upper stages based on F9 or F9 derived technology he is a) Telling you SX has no interest in doing this or b)It's a strategic deception to fool competitors into not investing. Time will tell which one of these statements is correct.
Quote from: Bynaus on 03/30/2017 12:52 pmWe shouldn't deal too much in certainties when it comes to SpaceX, especially when we are dealing with things that are technically possible - and a methane-fueled upper stage is. Last year, the suggestion that SpaceX is planing a circumlunar mission would have been laughed at, and serious people would have stated clearly and in all their seriousness that SpaceX does not deal with that space tourism crazy, isn't interested in the Moon, and wants to stay laser-focused on Mars. And yet, here we are... SX is in the transport business. People approached SX for this. If they didn't I doubt SX would care.
Quote from: Bynaus I fully agree that right now, a reusable upper stage is not on the top of their priority list, there are many other things up there. Nevertheless, if the prices come down further with the introduction of the New Glenn, and SpaceX thus needs to make that second stage reusable (perhaps even integrate it with the payload fairing to get a fully reusable "upper stage satellite delivery vehicle") to stay competitive, they will do it (unless it would be cheaper to develop and operate an ITS-derived solution).When the CEO and Chief Designer says no reusable upper stages based on F9 or F9 derived technology he is a) Telling you SX has no interest in doing this or b)It's a strategic deception to fool competitors into not investing. Time will tell which one of these statements is correct.
If you replace every part of a boat, is it still the same boat?By the same token, when is Falcon 9 no longer a Falcon 9? Only this morning an ex-SpaceX employee was talking on reddit about how all octawebs are now bolted instead of welded together. There have been so many tank stretches, engine upgrades, engine arrangements, recovery addons and a myriad of less visible alterations, one could argue that Falcon 9 has been retired once, possibly twice already.Granted, Block 5 will hopefully slow the pace of change, but I don't think it'll be the end of the alterations. I wouldn't be surprised if they discover additional problems in making a booster robust enough to fly three, four or more times. That's all uncharted territory and might need yet more alterations.Bottom line is that from my limited perspective, 'Falcon 9' refers to different launch vehicles, despite the common name. There have already been a subtle sequence of retirements.
In my mind there have been two substantially different Falcon 9 types to date, with the second type having run through two significant variations so far. The first type was the original Falcon 9 (Block 1), the Merlin 1C powered version that was much shorter, lighter, and as it turns out less capable than the subsequent type. There were only five of these examples. The second type has been the Merlin 1D powered versions using Octaweb. They have been called v1.1 and v1.2 (apparently Blocks 2 and 3). The Block 3 variant has a stretched second stage compared to the former, now retired Block 2 variant, but both tower over Block 1. There have been 28 of these Merlin 1D powered types, including the AMOS 6 launch vehicle that never made it to launch day.Any design that retains the diameter, the Octaweb, and the Merlin 1D engines will as I see it always group together, generally. They might be considered "Octaweb Falcons" or "Merlin 1D Falcons". - Ed Kyle
To me, it seems, the case for F9 exists in the long term only if Musk does not succeed in generating massive revenues from other sources. Sources which pretty much have to pay off if his Mars dream is to succeed in any case. And once that money becomes available, well, then F9 has little reason for continued existence, it would seem.
Quote from: Coastal Ron on 03/28/2017 09:26 pmQuote from: RoboGoofers on 03/28/2017 08:42 pmI assume SpaceX has a plan for when it'll retire F9.Why? Do you think Boeing had a retirement date picked out for the 737 when they first introduced it 49 years ago?I'm no expert, but it seems like the 737 is an outlier. Most other airliners have a production run of ~20-25 years. If that's a useful metric, then I'd expect SpaceX to stop production around 2030.
Quote from: RoboGoofers on 03/28/2017 08:42 pmI assume SpaceX has a plan for when it'll retire F9.Why? Do you think Boeing had a retirement date picked out for the 737 when they first introduced it 49 years ago?
I assume SpaceX has a plan for when it'll retire F9.