Nightfury Posted December 17, 2017 Share Posted December 17, 2017 Quote Link to comment Share on other sites More sharing options...
Nightfury Posted December 17, 2017 Share Posted December 17, 2017 Quote Link to comment Share on other sites More sharing options...
Jaff Posted December 17, 2017 Share Posted December 17, 2017 16 hours ago, sh1pman said: Soon... Love the timeline at the bottom! Quote Link to comment Share on other sites More sharing options...
Kerbal01 Posted December 17, 2017 Share Posted December 17, 2017 On 12/15/2017 at 10:54 AM, PB666 said: So lets see how long it takes for them to get the F9H out and braced. FH, not F9H. Quote Link to comment Share on other sites More sharing options...
PB666 Posted December 17, 2017 Share Posted December 17, 2017 1 hour ago, Nightfury said: That's a nice view of the robotic arm grappled to the Dragon. Quote Link to comment Share on other sites More sharing options...
harrisjosh2711 Posted December 17, 2017 Share Posted December 17, 2017 Sorry if this has already been discussed but how is SpaceX planning on fitting a combined diameter of 13.5 m worth of engines inside the 9m BFR? The only info I could find is a raptor vacuum is 2.4 meters and a atmospheric 1.3 m in diameter. Quote Link to comment Share on other sites More sharing options...
cubinator Posted December 17, 2017 Share Posted December 17, 2017 7 minutes ago, harrisjosh2711 said: Sorry if this has already been discussed but how is SpaceX planning on fitting a combined diameter of 13.5 m worth of engines inside the 9m BFR? The only info I could find is a raptor vacuum is 2.4 meters and a atmospheric 1.3 m in diameter. Circles. Quote Link to comment Share on other sites More sharing options...
harrisjosh2711 Posted December 17, 2017 Share Posted December 17, 2017 (edited) 21 minutes ago, cubinator said: Circles. Ok. I think I understand what you mean by circles. But I was really looking for a much more In depth explanation. I'm not challenging the idea I'm trying to figure out how I want to design the new engines for my BFR. FYI I study finance not rocket science. Yes I have taken some upper level calculus courses and learned about maximizing usage of area but that was in 3 dimensions. I'm looking at this from a single dimension such as a flat circle. Any thorough explanation would be appreciated. Nevermind I figured it out. Edited December 17, 2017 by harrisjosh2711 Quote Link to comment Share on other sites More sharing options...
cubinator Posted December 17, 2017 Share Posted December 17, 2017 7 minutes ago, harrisjosh2711 said: Ok. I think I understand what you mean by circles. But I was really looking for a much more In depth explanation. I'm not challenging the idea I'm trying to figure out how I want to design the new engines for my BFR. FYI I study finance not rocket science. Yes I have taken some upper level calculus courses and learned about maximizing usage of area but that was in 3 dimensions. I'm looking at this from a single dimension such as a flat circle. Any thorough explanation would be appreciated. The engines are not lined up in a line, rather the four vacuum engines are arranged in a ring with the two atmospheric engines in the center, as can be seen in the picture. This arrangement leaves plenty of room for each engine. I'm not sure what more explanation would help, other than a proof that all the circles fit in that space. Quote Link to comment Share on other sites More sharing options...
harrisjosh2711 Posted December 17, 2017 Share Posted December 17, 2017 (edited) 19 minutes ago, cubinator said: The engines are not lined up in a line, rather the four vacuum engines are arranged in a ring with the two atmospheric engines in the center, as can be seen in the picture. This arrangement leaves plenty of room for each engine. I'm not sure what more explanation would help, other than a proof that all the circles fit in that space. I think the best explanation is that diameter isn't that important but more so surface area. The BFR would have a surface area of 63.61 in a single dimension while a raptor vacuum takes up 4.52. All the engines together would only have a surface area of 22.06 leaving plenty of room behind (assuming my math is correct I did it quickly). Its basic geometry, something I haven't studied in a very long time. Thanks for the help though. I should have thought about it a little more before I jumped the gun and asked. Please correct me if I'm wrong, anyone. Edited December 17, 2017 by harrisjosh2711 Quote Link to comment Share on other sites More sharing options...
IncongruousGoat Posted December 17, 2017 Share Posted December 17, 2017 1 hour ago, harrisjosh2711 said: I think the best explanation is that diameter isn't that important but more so surface area. The BFR would have a surface area of 63.61 in a single dimension while a raptor vacuum takes up 4.52. All the engines together would only have a surface area of 22.06 leaving plenty of room behind (assuming my math is correct I did it quickly). Its basic geometry, something I haven't studied in a very long time. Thanks for the help though. I should have thought about it a little more before I jumped the gun and asked. Please correct me if I'm wrong, anyone. Actually, the important thing here is circle packing, which isn't quite the same as surface area. Quote Link to comment Share on other sites More sharing options...
harrisjosh2711 Posted December 17, 2017 Share Posted December 17, 2017 (edited) 38 minutes ago, IncongruousGoat said: Actually, the important thing here is circle packing, which isn't quite the same as surface area. Cool! With that said surface area would indeed serve as a proof that it is possible to place multiple objects within a diameter whos sum exceeds the objects diameter they are placed in correct(Although it wont maximize it)? From what I'm seeing no equation actually exist to maximize it...??? Obviously hexagonal packing would be the maximum. But either way once you calculated surface area of all circles placed, the area you have left could be calculated by [Surface Area(original) - ((π * r^2)*n)] correct or no? Edited December 17, 2017 by harrisjosh2711 Quote Link to comment Share on other sites More sharing options...
IncongruousGoat Posted December 17, 2017 Share Posted December 17, 2017 (edited) 11 minutes ago, harrisjosh2711 said: Cool! With that said surface area would indeed serve as a proof that it is possible to place multiple objects within a diameter whos sum exceeds the objects diameter they are placed in correct(Although it wont maximize it)? From what I'm seeing no equation actually exist to maximize it...??? Obviously hexagonal packing would be the maximum. But either way once you calculated surface area of all circles placed, the area you have left could be calculated by π * x^2 correct? Surface area isn't actually adequate to prove that a given set of circles can be packed into a certain space, especially with circles of disparate sizes, because no packing is optimal, which means not all available surface area is used. For circles of uniform radius, hexagonal packing is optimal, but this isn't necessarily the case for circles of non-uniform radius. You are correct, however, in saying that the area remaining can be calculated using the circle area formula. But this is definitely off-topic. Maybe I should start a circle-packing thread... Edited December 17, 2017 by IncongruousGoat Quote Link to comment Share on other sites More sharing options...
harrisjosh2711 Posted December 17, 2017 Share Posted December 17, 2017 Just now, IncongruousGoat said: Surface area isn't actually adequate to prove that a given set of circles can be packed into a certain space, especially with circles of disparate sizes, because no packing is optimal, which means not all available surface area is used. For circles of uniform radius, hexagonal packing is optimal, but this isn't necessarily the case for circles of non-uniform radius. You are correct, however, in saying that the area remaining can be calculated using the circle area formula. But this is definitely off-topic. Maybe I should start a circle-packing thread... Lol, why not? I will join in. Thanks for the info though. You learn something new every day. Quote Link to comment Share on other sites More sharing options...
PB666 Posted December 17, 2017 Share Posted December 17, 2017 26 minutes ago, IncongruousGoat said: Surface area isn't actually adequate to prove that a given set of circles can be packed into a certain space, especially with circles of disparate sizes, because no packing is optimal, which means not all available surface area is used. For circles of uniform radius, hexagonal packing is optimal, but this isn't necessarily the case for circles of non-uniform radius. You are correct, however, in saying that the area remaining can be calculated using the circle area formula. But this is definitely off-topic. Maybe I should start a circle-packing thread... It depends on the engine radius and the gimbal. In some rockets with multiple engines, the engines can only gimbal outwards. If your engine is 2.5 meters from the swivle and the nozzel is 1.0 meters in radius, and the gimbal is 15 degrees it means a nozzle actually occupies a space of π*(1.0 (1+sin(15))^2, (4.98 meters) but as you say in an optimal hexagon arrangement its about 5.5 meters square. That means a 6 rocket would be approximately cover 33 square meters (effectivly 40 circled) and required a radius of 3.5 meters (about twice the form factor of Kerbals largest fuel tank). If you are playing the Earth game, youll be using alot of stage 1 tanks that size, particularly if you are upping with cryogenics. Quote Link to comment Share on other sites More sharing options...
tater Posted December 18, 2017 Share Posted December 18, 2017 Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted December 18, 2017 Share Posted December 18, 2017 2 minutes ago, tater said: Oh yeah, there's still another launch this year. Quote Link to comment Share on other sites More sharing options...
tater Posted December 18, 2017 Share Posted December 18, 2017 32 minutes ago, CatastrophicFailure said: Oh yeah, there's still another launch this year. Let's cross our fingers for no unexpected fireworks what 39A before year's end, either, lol. After watching CRS-13, and the awesome kick-turn video after stage-sep, seeing FH do that X2 in January is gonna be a helluva thing. Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted December 18, 2017 Share Posted December 18, 2017 8 minutes ago, tater said: After watching CRS-13, and the awesome kick-turn video after stage-sep, seeing FH do that X2 in January is gonna be a helluva thing. I wonder if perhaps they’ll have side-facing cameras on the boosters, like the space shuttle occasionally did. That would be incredible! Quote Link to comment Share on other sites More sharing options...
tater Posted December 18, 2017 Share Posted December 18, 2017 (edited) 13 minutes ago, CatastrophicFailure said: I wonder if perhaps they’ll have side-facing cameras on the boosters, like the space shuttle occasionally did. That would be incredible! Right now a Falcon has a downward camera on S1, and an upwards one as well facing S2. S2 has a rear facing camera, and a fairing cam. 3 boosters, 3 downwards cams. One facing up on the core towards S2. 2 on S2. That's 6. Seems like if the downwards cam on the core is dead middle, then as they (the side boosters) translate away and flip, it should catch them. Edited December 18, 2017 by tater Quote Link to comment Share on other sites More sharing options...
cubinator Posted December 18, 2017 Share Posted December 18, 2017 2 hours ago, tater said: Right now a Falcon has a downward camera on S1, and an upwards one as well facing S2. S2 has a rear facing camera, and a fairing cam. 3 boosters, 3 downwards cams. One facing up on the core towards S2. 2 on S2. That's 6. Seems like if the downwards cam on the core is dead middle, then as they (the side boosters) translate away and flip, it should catch them. I don't know about the boosters but I know they're going to have a nice shot of car deployment. Quote Link to comment Share on other sites More sharing options...
Mitchz95 Posted December 18, 2017 Share Posted December 18, 2017 I didn't even know there was another launch this year! Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted December 18, 2017 Share Posted December 18, 2017 16 hours ago, tater said: Let's cross our fingers for no unexpected fireworks what 39A before year's end, either, lol. After watching CRS-13, and the awesome kick-turn video after stage-sep, seeing FH do that X2 in January is gonna be a helluva thing. Was it just an odd angle, or did the first stage do a horizontal-plane flip? It looked very different. In all prior flips I've seen, it looked like the first stage fired the nitrogen thruster pointing at the ground, causing the nose to head up toward radial and then back toward retrograde. In this flip, it looked like one of the lateral forward thrusters fired, causing the nose to yaw toward normal (or perhaps antinormal?) before rotating around toward retrograde. Is this really a change? If so, why? One possible reason, if this is a new change, might be that they are going to do horizontal-plane flips for the side boosters on Falcon Heavy rather than vertical-plane flips, to put more distance between the two boosters, and so this was an early practice run. Quote Link to comment Share on other sites More sharing options...
tater Posted December 18, 2017 Share Posted December 18, 2017 Yeah, I thought that looked different as well. Using paid launches to test stuff is what they do, after all. FH is going to be stunningly cool. Quote Link to comment Share on other sites More sharing options...
sh1pman Posted December 18, 2017 Share Posted December 18, 2017 (edited) Is there any info on FH max payload to LEO with full reusability? Excluding S2, obviously. I mean they say it’s 63t in fully expendable variant, so I wonder how much it’s going to lift with three reusable cores. Edited December 18, 2017 by sh1pman Quote Link to comment Share on other sites More sharing options...
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