Canopus Posted October 4, 2018 Share Posted October 4, 2018 1 minute ago, sh1pman said: I think you did, significantly more than once... So the reason why the Gateway will be at NRHO is because Orion can't visit any lower orbit. It is this way, because Orion's ESM is a copy of ATV service module and has 2 times less fuel than Apollo CSM. NASA decided to keep it small because SLS Block 1 can't send more than 26t to TLI... Did I get everything right? It could go to L1 or L2 but they have chosen the NRHO for reasons other than Delta V. In KSP DeltaV is always the priority to consider but this isn't necessarily true in real spaceflight. Link to comment Share on other sites More sharing options...
tater Posted October 4, 2018 Share Posted October 4, 2018 3 minutes ago, Canopus said: "A Delta V capability of 5 km/s covers the round trip between the Gateway and the surface." Then the quoted dry mass is wrong, or the RL-10s are better than any ever flown. The Isp needs to be 493s for 62 tonnes wet, 22 dry to have 5000 m/s dv. Just now, Canopus said: It could go to L1 or L2 but they have chosen the NRHO for reasons other than Delta V. In KSP DeltaV is always the priority to consider but this isn't necessarily true in real spaceflight. They chose the orbit they did for Gateway because Orion can get there and back. Link to comment Share on other sites More sharing options...
Canopus Posted October 4, 2018 Share Posted October 4, 2018 1 minute ago, tater said: Then the quoted dry mass is wrong, or the RL-10s are better than any ever flown. The Isp needs to be 493s for 62 tonnes wet, 22 dry to have 5000 m/s dv. They chose the orbit they did for Gateway because Orion can get there and back. Orion can get to Lunar L1 or L2, which seems to be better suited for a roundtrip to the Lunar surface at first sight But as i said may not actually be the better option. Link to comment Share on other sites More sharing options...
tater Posted October 4, 2018 Share Posted October 4, 2018 Alternately, the thing could have the best RL-10s, and the wet mass could be 66 tonnes. Just now, Canopus said: Orion can get to Lunar L1 or L2, which seems to be better suited for a roundtrip to the Lunar surface at first sight But as i said may not actually be the better option. I'm not seeing how it can have 5 km/s of dv given the mass, assuming it is not staged. Given the sort of stuff nanoracks is working on, it seems like a better option would be to have the decent props in their own tank, and that tank is then left on the surface, reducing the ascent dry mass. Refilling would then be via topping the ascent tanks, and simply replacing the decent tank (common bulkhead tank). That's assuming you want to turn spent tanks into habitable volume at some point. A lander based on ACES makes way more sense, IMO. Wonder if some % of that dry mass is not to be reused, but left on the surface as cargo/experiments/etc? They can get to 5000 m/s by buying just a few hundred m/s (it's cheaper to lose mass than add props). Link to comment Share on other sites More sharing options...
Canopus Posted October 4, 2018 Share Posted October 4, 2018 They call the engines "Rl-10 derivatives with deep throttling capabilities" so they might just be optimistic about new manufacturing capabilities. Link to comment Share on other sites More sharing options...
tater Posted October 4, 2018 Share Posted October 4, 2018 56 minutes ago, Canopus said: They call the engines "Rl-10 derivatives with deep throttling capabilities" so they might just be optimistic about new manufacturing capabilities. Yeah, but 493 is well outside the 465 they can get now (which is incredibly good, it’s a great engine). Link to comment Share on other sites More sharing options...
Canopus Posted October 4, 2018 Share Posted October 4, 2018 Just now, tater said: Yeah, but 493 is well outside the 465 they can get now (which is incredibly good, it’s a great engine). I'm sure they know what they are doing, might just be that the numbers for the mass in the paper are wrong. Link to comment Share on other sites More sharing options...
tater Posted October 4, 2018 Share Posted October 4, 2018 44 minutes ago, Canopus said: I'm sure they know what they are doing, might just be that the numbers for the mass in the paper are wrong. No doubt., so the lander can just make a RT, presumably. I saw something that did the math and basically a LEO-lunar surface mission need an extra 1.6 km/s if you go via the Gateway, vs direct from LEO. Link to comment Share on other sites More sharing options...
sh1pman Posted October 4, 2018 Share Posted October 4, 2018 1 hour ago, tater said: No doubt., so the lander can just make a RT, presumably. I saw something that did the math and basically a LEO-lunar surface mission need an extra 1.6 km/s if you go via the Gateway, vs direct from LEO. It should’ve been called the Roadblock instead of the Gateway then. Because it increases the difficulty of Moon missions instead of simplifying them. Link to comment Share on other sites More sharing options...
Canopus Posted October 4, 2018 Share Posted October 4, 2018 Purely from the KSP players delta v focused viewpoint though. Link to comment Share on other sites More sharing options...
sh1pman Posted October 5, 2018 Share Posted October 5, 2018 (edited) Extremely Unlikely Stage fits better at this point. Edited October 5, 2018 by sh1pman Link to comment Share on other sites More sharing options...
DAL59 Posted October 5, 2018 Share Posted October 5, 2018 1 hour ago, sh1pman said: Extremely Unlikely Stage fits better at this point. WAsn't it already delayed to 2023? So now EUS isn't until 2024 or 2025? SpaceX could make 2-5 BFRs in the time it takes NASA to make just one EUS. Link to comment Share on other sites More sharing options...
_Augustus_ Posted October 5, 2018 Author Share Posted October 5, 2018 Block I has literally three payloads: EM-1 EM-2 Europa Clipper You can't comanifest DSG modules on Block I with Orion, which would mean they'd require their own propulsion, in which case why not fly them on commercial LVs? I guess CAESAR, if selected, could fly on Block I and arrive at 67P faster, but that might exceed the mission's budget. An ice giant mission or Cassini follow up could work, but that's not in development. BA-2100 doesn't exist. Link to comment Share on other sites More sharing options...
Bill Phil Posted October 5, 2018 Share Posted October 5, 2018 13 hours ago, DAL59 said: WAsn't it already delayed to 2023? So now EUS isn't until 2024 or 2025? SpaceX could make 2-5 BFRs in the time it takes NASA to make just one EUS. I'd place the blame on Boeing and Congress. Boeing has pretty much completely screwed every aspect of SLS they could and Congress just doesn't care. Link to comment Share on other sites More sharing options...
_Augustus_ Posted October 5, 2018 Author Share Posted October 5, 2018 (edited) 11 hours ago, Bill Phil said: I'd place the blame on Boeing and Congress. Boeing has pretty much completely screwed every aspect of SLS they could and Congress just doesn't care. Boeing needs to be investigated for... a lot of things. Between their failures on SLS, their failures on Starliner which they try to cover up, falsely claiming they alone build and own SLS, and the libel against SpaceX, I wouldn't be surprised if they've broken some laws at this point. Unfortunately, this is Boeing we're talking about, and the US government is super corrupt - were either of those not the case, we probably wouldn't have an SLS rocket to criticize....... Edited October 6, 2018 by _Augustus_ Link to comment Share on other sites More sharing options...
DAL59 Posted October 5, 2018 Share Posted October 5, 2018 2 hours ago, _Augustus_ said: Boeing needs to be investigated for... a lot of things. Between their failures on SLS, their failures on Starliner which they try to cover up, falsely claiming they alone build and own SLS, and the libel against SpaceX, I wouldn't be surprised if they've broken some laws at this point. Plus the whole "forcing NASA to delay CC because they don't want SpaceX to beat them" thing. Link to comment Share on other sites More sharing options...
tater Posted October 5, 2018 Share Posted October 5, 2018 13 minutes ago, DAL59 said: Plus the whole "forcing NASA to delay CC because they don't want SpaceX to beat them" thing. That's not really a thing. The NASA Commercial Crew schedule they released still has SpaceX flying both the test and crew missions ahead of Boeing. The editorials are certainly shady, but I'd not draw any hard connections given the current public information we have regarding schedule. ISS docking opportunities are troublesome, and the Russians have dropped a crewman until they fly their new module, so ISS will be shorthanded to a total of 5 crew for the foreseeable future. Link to comment Share on other sites More sharing options...
Canopus Posted October 6, 2018 Share Posted October 6, 2018 https://spacenews.com/boeing-plans-changes-to-sls-upper-stages/ Link to comment Share on other sites More sharing options...
tater Posted October 10, 2018 Share Posted October 10, 2018 Ouch. Link to comment Share on other sites More sharing options...
tater Posted October 10, 2018 Share Posted October 10, 2018 The report: https://oig.nasa.gov/docs/IG-19-001.pdf Link to comment Share on other sites More sharing options...
Bill Phil Posted October 10, 2018 Share Posted October 10, 2018 My question is why even pick Boeing? The worst part is that NASA probably can't do anything about Boeing's screw ups. Link to comment Share on other sites More sharing options...
tater Posted October 11, 2018 Share Posted October 11, 2018 Wow. That report contains this: NASA is paying AJR $127,000,000 EACH to refurb the SSMEs that they will then throw into the ocean. So the 4 engines alone cost over a half a billion dollars. Every. Single. Launch. Link to comment Share on other sites More sharing options...
MinimumSky5 Posted October 11, 2018 Share Posted October 11, 2018 I've often wondered why NASA were told to use the RS25's, surely using RS68's would make more sense. Yes they don't have the same efficiency, but they're cheap and expendable. Link to comment Share on other sites More sharing options...
tater Posted October 11, 2018 Share Posted October 11, 2018 (edited) "Cheap" is how much, I wonder. Edited October 11, 2018 by tater Link to comment Share on other sites More sharing options...
Xd the great Posted October 11, 2018 Share Posted October 11, 2018 11 minutes ago, tater said: "Cheap" is how much, I wonder. Crew after recovery: Bruh, the 6.8g is much less than the 14-17g of the soyuz 10a escape. Did anyone ask for vodka and cigar? Link to comment Share on other sites More sharing options...
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