CatastrophicFailure Posted April 4, 2017 Share Posted April 4, 2017 16 minutes ago, tater said: https://www.flickr.com/photos/spacex/32915200224/in/photostream/ Purdy. Whats that "secondary" glut of fire coming out tho? Turbopimp exhaust? Link to comment Share on other sites More sharing options...
sevenperforce Posted April 4, 2017 Share Posted April 4, 2017 12 minutes ago, CatastrophicFailure said: Purdy. Whats that "secondary" glut of fire coming out tho? Turbopimp exhaust? Yeah, I believe so. Looks like the stage really got toasted. Link to comment Share on other sites More sharing options...
tater Posted April 4, 2017 Share Posted April 4, 2017 Yeah, I think it might have had a shorter entry burn, and got a lot hotter. Link to comment Share on other sites More sharing options...
sevenperforce Posted April 4, 2017 Share Posted April 4, 2017 15 minutes ago, tater said: Yeah, I think it might have had a shorter entry burn, and got a lot hotter. If you look closely at this photo, you can just make out what appears to be red-hot glowing grid fins. Link to comment Share on other sites More sharing options...
tater Posted April 4, 2017 Share Posted April 4, 2017 Yeah, hence the move to change them to titanium for block 5. Link to comment Share on other sites More sharing options...
BadMunky Posted April 4, 2017 Share Posted April 4, 2017 Four more launches of the same booster and they will have caught up to Blue Origin. Link to comment Share on other sites More sharing options...
sevenperforce Posted April 4, 2017 Share Posted April 4, 2017 8 minutes ago, BadMunky said: Four more launches of the same booster and they will have caught up to Blue Origin. Not gonna happen with this booster. But comparing the two is kind of pointless at this stage. Link to comment Share on other sites More sharing options...
KSK Posted April 4, 2017 Share Posted April 4, 2017 5 minutes ago, BadMunky said: Four more launches of the same booster and they will have caught up to Blue Origin. Not disparaging Blue Origin in the slightest - what they've done is impressive and I look forward to seeing New Glenn flying and landing. But there's really no comparison between a hop over the Karman line and returning the first stage of an orbital booster in terms of velocities, thermal loads on the airframe, aerodynamic stress and probably a whole bunch of other stuff that I know nothing about. I wouldn't have thought any of this needed to be pointed out on a KSP forum though. Link to comment Share on other sites More sharing options...
Exoscientist Posted April 4, 2017 Share Posted April 4, 2017 (edited) A Blue Origin's video animation from 2015 shows the solid rocket escape motor with handholds at about the 2:24 point: Be careful to mind your head while floating though! Edited April 4, 2017 by Exoscientist Link to comment Share on other sites More sharing options...
tater Posted April 4, 2017 Share Posted April 4, 2017 (edited) 56 minutes ago, BadMunky said: Four more launches of the same booster and they will have caught up to Blue Origin. When BO manages an orbital flight, they will have caught up to SpaceX almost 9 years ago: Falcon 1. As @KSK said, NS and F9 are not remotely comparable in capability. X-15 flew to space twice, but it flew (often within spitting distance of the Karman line) 62 other times. I should add that I'm the one that started the Blue Origin version of THIS thread, so I'm not attacking BO in the least, I like them, and expect that they will do great things. The whole "first reused to space" kerfuffle bugged me a little, since X-15 certainly did it first (both the X-15, and the B-52 carrier were reused, after all (easily, like aircraft)). On top of that, X-15 did it manned. Shuttle did it what, 139 times? Also manned. Edited April 4, 2017 by tater Link to comment Share on other sites More sharing options...
KSK Posted April 4, 2017 Share Posted April 4, 2017 9 minutes ago, tater said: *snip* I should add that I'm the one that started the Blue Origin version of THIS thread, so I'm not attacking BO in the least, I like them, and expect that they will do great things. The whole "first reused to space" kerfuffle bugged me a little, since X-15 certainly did it first (both the X-15, and the B-52 carrier were reused, after all (easily, like aircraft)). On top of that, X-15 did it manned. SpaceX - better than starting manned? Link to comment Share on other sites More sharing options...
sevenperforce Posted April 4, 2017 Share Posted April 4, 2017 (edited) Aye. Blue Origin's achievements are definitely impressive and I give them all kinds of props for that, but honestly every various attempt at reusability is the "first" for its own reasons. DC-X, Grasshopper, and F9dev (along with a few others) beat BO to VTVL rocketry. Earlier Falcon 9 launches beat BO to in-air restarts of launch vehicles during atmospheric re-entry. The X-15 and the Shuttle beat BO to intact recovery of a powered exoatmospheric vehicle. Blue Origin can lay claim to being the first company to launch a rocket vertically beyond the Karman line and return it to a vertical propulsive landing. Good for them. But we all stand on the shoulders of giants. Edited April 4, 2017 by sevenperforce Link to comment Share on other sites More sharing options...
DerekL1963 Posted April 4, 2017 Share Posted April 4, 2017 1 hour ago, sevenperforce said: If you look closely at this photo, you can just make out what appears to be red-hot glowing grid fins. Glowing red-hot - or reflecting the red-orange light from the engine exhaust? Link to comment Share on other sites More sharing options...
sevenperforce Posted April 4, 2017 Share Posted April 4, 2017 9 minutes ago, DerekL1963 said: Glowing red-hot - or reflecting the red-orange light from the engine exhaust? It's a tossup, but I think it's the former. The light is brighter closer to the stage wall, which is what we'd expect if it was radiating away heat but not if it was reflecting something at the bottom of the stage. The color temperature is also a lot warmer than the exhaust reflection would be. Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted April 4, 2017 Share Posted April 4, 2017 31 minutes ago, sevenperforce said: It's a tossup, but I think it's the former. The light is brighter closer to the stage wall, which is what we'd expect if it was radiating away heat but not if it was reflecting something at the bottom of the stage. The color temperature is also a lot warmer than the exhaust reflection would be. I don't think so, it's gotta just be reflection. Aluminum melts before it gets hot enough to glow. IIRC Musk said what we saw blazing on the video was the paint burning off. Source: I've melted my share of aluminum. Occasionally intentionally. Link to comment Share on other sites More sharing options...
Steel Posted April 4, 2017 Share Posted April 4, 2017 Yeah just to back up @CatastrophicFailure, the melting point of aluminium is 933 K (so adding a couple of hundred degrees for aerospace alloys, lets say 1100 K). Orange glow occurs at about 1200 K, so aluminium is molten before it starts to glow orange. Link to comment Share on other sites More sharing options...
sevenperforce Posted April 4, 2017 Share Posted April 4, 2017 11 minutes ago, CatastrophicFailure said: I don't think so, it's gotta just be reflection. Aluminum melts before it gets hot enough to glow. IIRC Musk said what we saw blazing on the video was the paint burning off. Source: I've melted my share of aluminum. Occasionally intentionally. Incandescence begins around 500 C for most metals and Al doesn't melt until 660 C. But I suppose Al would be hella weak at that temperature. Link to comment Share on other sites More sharing options...
tater Posted April 4, 2017 Share Posted April 4, 2017 (edited) 1 hour ago, DerekL1963 said: Glowing red-hot - or reflecting the red-orange light from the engine exhaust? Good point in that image. Before it cut out, the onboard video clearly showed the grid fins glowing, however, and block 5 is specifically addressing this issue, so even if that image is indeed a reflection, they're pretty hot, particularly this landing. Edited April 4, 2017 by tater Link to comment Share on other sites More sharing options...
Steel Posted April 4, 2017 Share Posted April 4, 2017 16 minutes ago, sevenperforce said: Incandescence begins around 500 C for most metals and Al doesn't melt until 660 C. But I suppose Al would be hella weak at that temperature. Incandescence does, but its starts off as a fairly noticeable red until much higher temperatures. Link to comment Share on other sites More sharing options...
sevenperforce Posted April 4, 2017 Share Posted April 4, 2017 6 minutes ago, Steel said: Incandescence does, but its starts off as a fairly noticeable red until much higher temperatures. And the color I'm referencing is definitely a noticeable dull red. Link to comment Share on other sites More sharing options...
Steel Posted April 4, 2017 Share Posted April 4, 2017 Just now, sevenperforce said: And the color I'm referencing is definitely a noticeable dull red. It looks orange to me! Unfortunately with computer monitors it's not really possible to tell exactly what colour either of us are seeing though, but my on my screen it looks orange! Link to comment Share on other sites More sharing options...
sevenperforce Posted April 4, 2017 Share Posted April 4, 2017 Curiouser and curiouser! Link to comment Share on other sites More sharing options...
DerekL1963 Posted April 4, 2017 Share Posted April 4, 2017 (edited) 33 minutes ago, sevenperforce said: Incandescence begins around 500 C for most metals and Al doesn't melt until 660 C. True - but the color of the incandescence varies with temperature independent of the composition of the metal. Edited April 4, 2017 by DerekL1963 Link to comment Share on other sites More sharing options...
sevenperforce Posted April 4, 2017 Share Posted April 4, 2017 Right. So the faint red glow I'm seeing in the image corresponds to about 500-550 degrees C. Link to comment Share on other sites More sharing options...
mikegarrison Posted April 4, 2017 Share Posted April 4, 2017 Aluminum (like all metals, as far as I know) loses strength long before it "melts". Using Ti instead of Al is a traditional aerospace engineering solution to any "it gets too hot" issue. (Ti, however, is more chemically sensitive than Al, particularly to hydraulic fluid. I don't know if that's an issue for the grid fins or not.) Link to comment Share on other sites More sharing options...
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