Timeline for Why is Falcon 9's shape so tall and skinny?
Current License: CC BY-SA 3.0
15 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 10, 2018 at 15:15 | comment | added | Vikki | I was going to ask why SpaceX didn't transport the Falcon 9 by rail to take advantage of the higher clearances... and then I found out that, while the maximum allowed height is indeed greater for rail, the maximum width is limited to only 3.25 meters, which would require making the Falcon 9 even heavier. | |
| Nov 6, 2017 at 10:36 | comment | added | pjc50 | Logistics is a real technical reason - every product engineer needs to take into account assembly and delivery of their product. It would be no use building a great rocket that gets stuck on the first bridge after the factory. There are other options (move the factory, build a giant VAB like the shuttle) but they cost money too, and SpaceX is all about cost optimisation. | |
| Jun 3, 2015 at 1:38 | comment | added | Junior Miranda | yes the 7.44m mark refers to the side tanks of 1rst stage - on Proton. The very reason for they use the 6 tanks was the Soviet rail gauge in the 60´s. Proton was conceived as an ICBM for a huge H Bomb. | |
| Jun 2, 2015 at 17:18 | comment | added | geoffc | @JuniorMiranda Is that 7.44 m width with the side fuel tanks? They look like strapon boosters on Proton, but are really the fuel tanks and engines. Consider the main core instead, I would think. | |
| Jun 2, 2015 at 17:16 | comment | added | Junior Miranda | Interesting to note is that 8K82 Proton is only 7,44m wide in its first stage, wich is ~20 meters long; The rest of the body has a 4,15m diameter, going to 3,6 meters on Block D/DM fourth stage. | |
| Jun 2, 2015 at 17:14 | comment | added | Junior Miranda | Railroad gauges are a limiting factor for Soviet/Russian boosters' diameters. The BVGD blocks for R-7 rockets were designed with this constraints in mind - besides other factors, of course. | |
| Jun 1, 2015 at 14:40 | comment | added | radex | Thanks geoffc & @VedantChandra for your answers! It's quite fascinating to me that a design of a rocket would be primarily predicated upon logistical, not "real" technical reasons. | |
| Jun 1, 2015 at 14:37 | vote | accept | radex | ||
| Jun 1, 2015 at 3:23 | comment | added | Vedant Chandra | @andy256 Come on, it's not 'against the rules' to show emotion here. He's pointing out something ironic, it's perfectly alright. | |
| May 31, 2015 at 23:38 | comment | added | user8406 | @Hobbes In what way is it relevant that geoffc is amused? | |
| May 31, 2015 at 22:13 | comment | added | Loren Pechtel | The reality is that to take something over 14' tall (total vehicle height, not just your cargo) down the road involves a lot of headaches and sometimes isn't even possible (if you can't avoid going under a bridge somewhere.) Since there is transporter and then ground clearance below the rocket 12' is about the limit. | |
| May 31, 2015 at 22:10 | comment | added | geoffc | @andy256 Its amusing to me, since you think of fat not tall as the problem in normal life. (Tall is usually good, fat is usually bad). | |
| May 31, 2015 at 13:33 | comment | added | Hobbes | It could do with some references, but it's all relevant. The height of a road transport is limited by bridges etc. 3.6 m is about the biggest cylinder you can fit on a low loader and drive around the country in a reasonably routine manner. You could go much wider (taking up two lanes) if you're prepared to close road sections for the passage of the transport, but as Geoff said, if you want the stage to be cylindrical, then the extra width available is of no use and you're limited by height restictions. | |
| May 31, 2015 at 11:42 | comment | added | user8406 | Not the down voter, but this answer seems to have lots of info without demonstrated relevance. The last sentence needs explanation. IMO the word amusingly would be appropriate in chat, but not in a factual answer. | |
| May 31, 2015 at 10:42 | history | answered | geoffc | CC BY-SA 3.0 |