tater Posted February 25, 2021 Author Share Posted February 25, 2021 6 minutes ago, sevenperforce said: Tangentially, I wonder what the BE-4 uses for startups. I believe the BE-3 uses a set of sacrificial solid igniters that have to be replaced after each flight. Yeah, no idea other than it obviously has to restart at least once or twice. (for BO use, anyway) Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted February 26, 2021 Share Posted February 26, 2021 Well this is definitely not to scale. Centaur III is roughly 3 meters across. The two RL10C-1-1s on Centaur V ARE bigger than the RL10C-1 on Centaur III, but only slightly (157 cm dia vs 145 cm dia). Also I wasn't aware of this but it seems ACES has been entirely canceled. https://spacenews.com/ula-studying-long-term-upgrades-to-vulcan/ Quote Link to comment Share on other sites More sharing options...
tater Posted February 26, 2021 Author Share Posted February 26, 2021 1 hour ago, sevenperforce said: Also I wasn't aware of this but it seems ACES has been entirely canceled. Sounds like some is just being rebranded for Centaur. IVF is great, and a refillable upper stage reusable in space would be a profoundly valuable asset. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted February 26, 2021 Share Posted February 26, 2021 1 hour ago, tater said: Sounds like some is just being rebranded for Centaur. IVF is great, and a refillable upper stage reusable in space would be a profoundly valuable asset. The way I'm reading it, they are abandoning IVF. Quote Link to comment Share on other sites More sharing options...
tater Posted February 26, 2021 Author Share Posted February 26, 2021 10 minutes ago, sevenperforce said: The way I'm reading it, they are abandoning IVF. Hard to tell from the article, but I am afraid you are right. Awful decision, ACES was the best thing ULA ever came up with. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted March 3, 2021 Share Posted March 3, 2021 Answer: yes, because of course you do. Tweak that thrust. Quote Link to comment Share on other sites More sharing options...
tater Posted March 3, 2021 Author Share Posted March 3, 2021 Or the thrust curves if you have that control. Quote Link to comment Share on other sites More sharing options...
Spaceman.Spiff Posted March 4, 2021 Share Posted March 4, 2021 Ugh. I didn't know that ACES was cancelled. That is really unfortunate. Even worse, they're not going to use the IVF tech??? That's just dumb. Random side note, why is Centaur V not using the same RL-10 variant as the Delta 4? It seems like the extra efficiency would be worth it. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted March 4, 2021 Share Posted March 4, 2021 54 minutes ago, Spaceman.Spiff said: Random side note, why is Centaur V not using the same RL-10 variant as the Delta 4? It seems like the extra efficiency would be worth it. The RL10C-1-1 is 2/3 of the dry weight of the RL10B-2. It's also substantially smaller: 59% the length and 73% the width. The nozzle is fixed rather than extensible, which makes it simpler and reduces failure modes. The Centaur family of upper stages has always had very good dry mass ratios, which means reducing weight is super important. Quote Link to comment Share on other sites More sharing options...
DDE Posted March 11, 2021 Share Posted March 11, 2021 Old customer checking in Quote Link to comment Share on other sites More sharing options...
mikegarrison Posted March 12, 2021 Share Posted March 12, 2021 15 hours ago, DDE said: Old customer checking in The tables are turned, as the Earth spies on the satellite. Quote Link to comment Share on other sites More sharing options...
tater Posted March 12, 2021 Author Share Posted March 12, 2021 12 hours ago, mikegarrison said: The tables are turned, as the Earth spies on the satellite. Spoiler Quote Link to comment Share on other sites More sharing options...
Ziggy Kerman Posted March 13, 2021 Share Posted March 13, 2021 On 3/3/2021 at 4:42 PM, sevenperforce said: Answer: yes, because of course you do. Tweak that thrust. For my Uranus I, I always tweak the thrust to get a 1.01+ TWR so it can burn for as long as possible Quote Link to comment Share on other sites More sharing options...
Spaceman.Spiff Posted March 22, 2021 Share Posted March 22, 2021 I think this would’ve been awesome. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted March 29, 2021 Share Posted March 29, 2021 Vulcan pathfinder sitting on the pad. Quote Link to comment Share on other sites More sharing options...
tater Posted April 17, 2021 Author Share Posted April 17, 2021 Quote Link to comment Share on other sites More sharing options...
tater Posted April 19, 2021 Author Share Posted April 19, 2021 Quote Link to comment Share on other sites More sharing options...
StrandedonEarth Posted April 19, 2021 Share Posted April 19, 2021 That doesn't inspire a lot of confidence in New Glenn flying regularly anytime soon. Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted April 19, 2021 Share Posted April 19, 2021 Blue Origin who? Quote Link to comment Share on other sites More sharing options...
Dfthu Posted April 19, 2021 Share Posted April 19, 2021 4 hours ago, tater said: Wonder how many satellites they can cram into a Atlas, also wonder what config the Atlas will be Quote Link to comment Share on other sites More sharing options...
RCgothic Posted April 19, 2021 Share Posted April 19, 2021 (edited) This decision looks bonkers. 1) Not New Glenn. Ouch, that's embarrassing. 2) Not Vulcan, which uses BO's engines. Again, ouch. 3) Atlas V *starts* from about 10x Falcon 9's internal cost to SpaceX, so that's a huge cost handicap before they even start. 4) Thought ULA were supposed to be phasing Atlas out? Better put that larger fairing to use and launch a lot of sats at once. The heaviest Atlas can put up about 25% more mass than F9 in reusable mode but at a still higher price that perhaps counters the benefit of using a heavier variant. Edited April 19, 2021 by RCgothic Quote Link to comment Share on other sites More sharing options...
tater Posted April 19, 2021 Author Share Posted April 19, 2021 The Amazon constellation is supposed to be 3200+ sats. Assuming they dumped whatever their original design was in favor of a copy of Starlink, then maybe they can launch something like 50 of them at once? That gets some in orbit. Also, and this is critical, they were given bandwidth for it based on them deploying some % of the says within 6 years (half?), else they can't launch any more. Quote Link to comment Share on other sites More sharing options...
tater Posted April 24, 2021 Author Share Posted April 24, 2021 Monday: Quote Link to comment Share on other sites More sharing options...
tater Posted April 24, 2021 Author Share Posted April 24, 2021 (edited) On 4/19/2021 at 2:34 PM, RCgothic said: This decision looks bonkers. 1) Not New Glenn. Ouch, that's embarrassing. NG just will not be ready, and certainly not be in full operational cadence for a while after it flies (2023?). And 1600 to space by 2026... Quote 2) Not Vulcan, which uses BO's engines. Again, ouch. A couple issues. One, Vulcan probably flies next year. Two, Vulcan can always be swapped for Atlas V. Three, I think the first Vulcan launches are already spoken for—dunno what the total they can make in a year even is. But yeah. I suppose this is Jeff throwing money at ULA for their failure to deliver on time, too. Quote 3) Atlas V *starts* from about 10x Falcon 9's internal cost to SpaceX, so that's a huge cost handicap before they even start. Yeah. Crazy. Atlas V is simply not a competitive commercial vehicle, it is ONLY used for government launches, and only because the government wants to throw pork at them to keep multiple providers around. Minus gov contracts, they simply don't exist. Except for these 9 launches. LOL. Quote 4) Thought ULA were supposed to be phasing Atlas out? Better put that larger fairing to use and launch a lot of sats at once. The heaviest Atlas can put up about 25% more mass than F9 in reusable mode but at a still higher price that perhaps counters the benefit of using a heavier variant. SpaceX would launch them, they have said explicitly they would happily launch competing constellations. What's interesting to me is that AMZN is a public company... how can you justify to shareholders that you are spending 2X what they should on launches? AMZN doesn't own a rocket company, so they can't say they don't want to support a competing delivery service. Edited April 24, 2021 by tater Quote Link to comment Share on other sites More sharing options...
StrandedonEarth Posted April 24, 2021 Share Posted April 24, 2021 On 4/19/2021 at 1:34 PM, RCgothic said: 1) Not New Glenn. Ouch, that's embarrassing. 2) Not Vulcan, which uses BO's engines. Again, ouch. 3) Atlas V *starts* from about 10x Falcon 9's internal cost to SpaceX, so that's a huge cost handicap before they even start. 4) Thought ULA were supposed to be phasing Atlas out? Uopn further reflection: 1) Yup 2) Yup. But... 3) Ignoring historical costs, what is the contracted price for this contract? 4) How many Atlas Vs do they have in inventory? Apparently this order eats up most of their inventory. clearing the way for Vulcan Quote Link to comment Share on other sites More sharing options...
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