Nuke Posted June 20 Share Posted June 20 (edited) i think they inherited a lot of stuff from the military wrt connectors. these are highly standardized and domestically produced by a number of contractors to ensure constant supply. at least thats the way it was. we might be using a completely different set of connectors now. i cant imagine the old connectors having very good characteristics for high speed digital information. not sure if civilian (including spacex) craft use the same connectors or not. seems it would make sense, its just a connector and if you got the bread you can just buy one (milspec so probably expensive). Edited June 20 by Nuke Quote Link to comment Share on other sites More sharing options...
AckSed Posted June 21 Share Posted June 21 https://arstechnica.com/space/2024/06/ars-live-recap-is-spacex-a-launch-company-or-a-satellite-communications-company/ Transcript of talk here: https://cdn.arstechnica.net/wp-content/uploads/2024/06/Starlink-Conversation-Transcript.txt tl;dr With Starlink, SpaceX is the largest satellite operator in the world right now, both in sheer numbers of sats and ground stations, and in revenue: Viasat/Inmarsat and Intelsat/SES ~$4 billion, Starlink $6.6 billion. They have a foot in the door with Indonesia, which is a prime market for satellite internet. If they enter India, despite the recalcitrance India is showing to OneWeb, that's an even bigger market. Estimated launch costs are below $20 million. Quote Link to comment Share on other sites More sharing options...
Deddly Posted June 21 Share Posted June 21 10 hours ago, tater said: If they were to send up a Dragon, they'd probably just send one up, not add seats. As far as I know they're still aiming for the 26th to send Starliner home (?). Or they could send one up with empty IVA suits Quote Link to comment Share on other sites More sharing options...
tater Posted June 21 Share Posted June 21 1 hour ago, Deddly said: Or they could send one up with empty IVA suits Yeah, they'd have to I think (unless the hose couplings are the same for different suit types (which in retrospect, they should be in future if they aren't). Quote Link to comment Share on other sites More sharing options...
JoeSchmuckatelli Posted June 21 Share Posted June 21 8 hours ago, Deddly said: Or they could send one up with empty IVA suits Or just adapters? Are the seats too specific to SX suits that no one else could ride? - I know a Cosmonaut has ridden Crew Dragon... Did he have a SX suit? Quote Link to comment Share on other sites More sharing options...
tater Posted June 21 Share Posted June 21 46 minutes ago, JoeSchmuckatelli said: Or just adapters? Are the seats too specific to SX suits that no one else could ride? - I know a Cosmonaut has ridden Crew Dragon... Did he have a SX suit? All crew who go up in Soyuz wear Russian suits. All who go in Dragon wear SpaceX suits, etc. Spoiler Quote Link to comment Share on other sites More sharing options...
DAL59 Posted June 21 Share Posted June 21 https://cdn.discordapp.com/attachments/881015698191712317/1253547962659766303/Selection_Decision_Document_-_Rapid_Design_Studies_for_MSR_-_June_2024.pdf?ex=66764104&is=6674ef84&hm=bc3eee5177f103a813109b64c7bc26f37b02efe6511653e35672ddfec3ee77e6 SpaceX is now officially telling Nasa it could land on Mars in 2029! Quote Link to comment Share on other sites More sharing options...
Nuke Posted June 21 Share Posted June 21 i guess their collection system is a guy in a suit. Quote Link to comment Share on other sites More sharing options...
JoeSchmuckatelli Posted June 21 Share Posted June 21 18 minutes ago, DAL59 said: telling Nasa it could land on Mars in 2029 Likely the only entity that could without risking a serious eye roll cramp. Ambitious but not absurd Quote Link to comment Share on other sites More sharing options...
darthgently Posted June 21 Share Posted June 21 (edited) https://imgur.com/rjyNyIr Edited June 21 by darthgently Quote Link to comment Share on other sites More sharing options...
Jacke Posted June 22 Share Posted June 22 (edited) 14 hours ago, DAL59 said: SpaceX is now officially telling Nasa it could land on Mars in 2029! Well, well, well.... Let's see if SpaceX gets anything beyond LEO/GTO before 2029.... Well, besides a few Falcon Heavies. Edited June 22 by Jacke Quote Link to comment Share on other sites More sharing options...
Flavio hc16 Posted June 22 Share Posted June 22 15 hours ago, Nuke said: i guess their collection system is a guy in a suit. Tesla bot Quote Link to comment Share on other sites More sharing options...
JoeSchmuckatelli Posted June 22 Share Posted June 22 7 hours ago, Jacke said: Well, well, well.... Let's see if SpaceX gets anything beyond LEO/GTO before 2029.... Well, besides a few Falcon Heavies. Here are the 2020 predictions for reference https://spacenews.com/spacexs-2020-ambitions-tempered-by-2019-outcomes/ Quote Link to comment Share on other sites More sharing options...
Brotoro Posted June 22 Share Posted June 22 11 hours ago, Jacke said: Well, well, well.... Let's see if SpaceX gets anything beyond LEO/GTO before 2029.... Well, besides a few Falcon Heavies. And the Falcon 9 launches of Euclid toward Sun-Earth L2 and Odysseus moon lander. Quote Link to comment Share on other sites More sharing options...
tater Posted June 22 Share Posted June 22 Loads of stuff in here. Including a decent segment on why you need to just fly stuff. They simulate and test all they can on the ground (look at the complex "can crushers" and thrust simulators), but test stands are not experiencing X gs, and maneuvering. Basically everything that sensible people here have been saying since forever. Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted June 22 Share Posted June 22 And confirmation on injecting several hundred kilos of ice into the tanks. Quote Link to comment Share on other sites More sharing options...
Brotoro Posted June 22 Share Posted June 22 20 minutes ago, Ultimate Steve said: And confirmation on injecting several hundred kilos of ice into the tanks. Which is just flippin weird. Quote Link to comment Share on other sites More sharing options...
tater Posted June 22 Share Posted June 22 2 minutes ago, Brotoro said: Which is just flippin weird. Combustion products of CH4 and LOX are CO2 and H2O. The pressurization gas is turbopump exhaust. Quote Link to comment Share on other sites More sharing options...
Brotoro Posted June 22 Share Posted June 22 (edited) Using the turbopump exhaust to pressurize is the weird part. I was expecting some sort of heat exchanger. No-part-is-best-part is fine, but not if it forces you to add other parts like better LOX tank filters and ice-catching sieves, or whatever they added for IFT-4. Edited June 22 by Brotoro Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted June 22 Share Posted June 22 5 minutes ago, Brotoro said: Using the turbopump exhaust to pressurize is the weird part. I was expecting some sort of heat exchanger. No-part-is-best-part is fine, but not if it forces you to add other parts like better LOX tank filters and ice-catching sieves, or whatever they added for IFT-4. I did the math for another chat somewhere else, at a minimum, assuming I did the math right, you would need 77.5 megawatts just for the phase change on super heavy (assumed super heavy was entirely lox, bc I couldn't be bothered). More for inefficiencies, more if you want the gas to be anything higher than 91 kelvin. And then you have to pump fuel and exhaust through it which is gonna lead to some efficiency losses. More connections, possibly another pump system, something that has to be built into all 33 engines... However I don't really know what a 77.5 megawatt heat exchanger would look like. That sounds like a big number but super heavy is so big that it could be a tiny number. I don't know enough about heat exchangers and raptor to do more than a simple ballpark "how much heat moves through this wall" with guesstimate temperatures and materials and thicknesses. So I really couldn't tell you if it's a bone headed decision or something that was heavy and complex enough that filters looked like (or are) the better option. Quote Link to comment Share on other sites More sharing options...
Brotoro Posted June 22 Share Posted June 22 (edited) I don't think you would use all 33 engines to pressurize the tank… only three engines are running at various times, so I'd think you need to use those to do the pressurization. Edited June 22 by Brotoro Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted June 22 Share Posted June 22 16 minutes ago, Brotoro said: I don't think you would use all 33 engines to pressurize the tank… only three engines are running at various times, so I'd think you need to use those to do the pressurization. The volume of gas that needs to enter the tank is proportional to the number of engines running. Doing everything off of those three means you run into trouble if one of those three fail, and during times when fewer than 33 engines are running you have far more pressurization than needed and need to deal with that somehow. Plus, they really want as few variants of the engine as possible. Granted the header tanks probably have a different pressurization system (in the video, one of the ship (?) header tanks was shown to use COPVs, unsure about super heavy). If I were designing this, it would probably either be its own system (maybe with its own burner) or one per engine. It is definitely possible to do it on just a few engines though. With what I know, I don't believe that would be the best way. Also, very off topic, but I really loved Long Term on Laythe back in the day and I don't think that has ever come up in conversation. Quote Link to comment Share on other sites More sharing options...
Brotoro Posted June 22 Share Posted June 22 Early on, I thought autogenous pressurization and Starship heatshield would be the two biggest problems. I was surprised at how quickly they seemed to solve the first one…but it appears they are still working on getting it right. Thanks for the comment about my Long-term Laythe missions. Quote Link to comment Share on other sites More sharing options...
magnemoe Posted June 22 Share Posted June 22 4 hours ago, Ultimate Steve said: I did the math for another chat somewhere else, at a minimum, assuming I did the math right, you would need 77.5 megawatts just for the phase change on super heavy (assumed super heavy was entirely lox, bc I couldn't be bothered). More for inefficiencies, more if you want the gas to be anything higher than 91 kelvin. And then you have to pump fuel and exhaust through it which is gonna lead to some efficiency losses. More connections, possibly another pump system, something that has to be built into all 33 engines... However I don't really know what a 77.5 megawatt heat exchanger would look like. That sounds like a big number but super heavy is so big that it could be a tiny number. I don't know enough about heat exchangers and raptor to do more than a simple ballpark "how much heat moves through this wall" with guesstimate temperatures and materials and thicknesses. So I really couldn't tell you if it's a bone headed decision or something that was heavy and complex enough that filters looked like (or are) the better option. You already use the methane for cooling so you can just tap off the hot gas just before firing. Lox goes straight into the top turbo pump so they tap into the flow after the burner where you have hot oxygen but also co2 and steam. This is an issue more so as if you have an heating loop, that to do with the oxygen not needed? Quote Link to comment Share on other sites More sharing options...
Nuke Posted June 23 Share Posted June 23 5 hours ago, Brotoro said: Using the turbopump exhaust to pressurize is the weird part. I was expecting some sort of heat exchanger. No-part-is-best-part is fine, but not if it forces you to add other parts like better LOX tank filters and ice-catching sieves, or whatever they added for IFT-4. arent you hurting your isp if you hold on to exhaust products from the turbopump. i guess its useful for margarita night on the iss. 4 hours ago, Ultimate Steve said: I did the math for another chat somewhere else, at a minimum, assuming I did the math right, you would need 77.5 megawatts just for the phase change on super heavy (assumed super heavy was entirely lox, bc I couldn't be bothered). More for inefficiencies, more if you want the gas to be anything higher than 91 kelvin. And then you have to pump fuel and exhaust through it which is gonna lead to some efficiency losses. More connections, possibly another pump system, something that has to be built into all 33 engines... However I don't really know what a 77.5 megawatt heat exchanger would look like. That sounds like a big number but super heavy is so big that it could be a tiny number. I don't know enough about heat exchangers and raptor to do more than a simple ballpark "how much heat moves through this wall" with guesstimate temperatures and materials and thicknesses. So I really couldn't tell you if it's a bone headed decision or something that was heavy and complex enough that filters looked like (or are) the better option. thats like a third of a skylon precooler. Quote Link to comment Share on other sites More sharing options...
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