My personal observation having worked on more than one large (>$1B) successful aerospace program and large failures: The bigger your "team" of companies when tackling a contract, the more likely you are to fail to achieve the technical objectives of the program.A system where the customer (NASA) owns the requirements and are the sole arbiters of whether/how they can be modified, just doesn't lend itself well (in our times) to multiple partners and subcontractors. It fosters an unworkable bureaucracy and culture of infighting.Overcoming these forces requires near "limitless" money and focused national will. Minimizing subcontracts and interface requirement documents between companies maximizes your chance for technical success. Key metric: How many weeks does it take to modify a requirement
The use of New Glenn for prop transport and the AE/DE/TE triumvirate can both be true. But it requires betting the farm on New Glenn. Maybe that's a good reason for Blue to be the prime; if things go pear-shaped, they're on the hook to pay their subs.
This sounds a bit like somebody has stealth-cancelled the BE-7, or at least back-burnered it.
Quote from: TheRadicalModerate on 12/10/2022 09:15 pmThe use of New Glenn for prop transport and the AE/DE/TE triumvirate can both be true. But it requires betting the farm on New Glenn. Maybe that's a good reason for Blue to be the prime; if things go pear-shaped, they're on the hook to pay their subs.Betting the farm on New Glenn? No disrespect but if they cant execute on New Glenn by 2028+ then BO has no business bidding on any kind of contract like this.They should be betting the farm, they seem to need the motivation.
[Replying to methalox delivery discussions upthread - couldn't seem to quote on mobile]Alternatively, if Dynetics wins, their architecture (as of Humans to Mars summit 2022) already includes starship as a refuelling option alongside Vulcan. That eliminates monopoly; provides redundancy; and increases commonality: both landers use methalox, and if ALPACA can be refilled from either SS or Centaur, then there is (probably) a standardised refuelling interface on each of them - allowing vastly increased flexibility for both ALPACA and Starship (and anyone else).
[Replying to methalox delivery discussions upthread - couldn't seem to quote on mobile]Alternatively, if Dynetics wins, their architecture (as of Humans to Mars summit 2022) already includes starship as a refuelling option alongside Vulcan.
Quote from: jdon759 on 12/11/2022 08:13 pm[Replying to methalox delivery discussions upthread - couldn't seem to quote on mobile]Alternatively, if Dynetics wins, their architecture (as of Humans to Mars summit 2022) already includes starship as a refuelling option alongside Vulcan. That potentially mis-characterizes what Andy Crocker (Dynetics Human Landing Systems Program Manager) said and showed at the H2M presentation. He said Vulcan or Starship could launch the Dynetics propellant tankers. He did not say A Dynetics vehicle could transfer propellant from (or to) a SpaceX vehicle.
However, there's still a remaining question: Because the likely crop of medium-to-heavy, non-refuelable launchers will give you 12-15t of prop to NRHO, and a Starship tanker might give you as much as 530t with full refueling, do you bias your design for higher performance and assume a large prop load, or do you design for the lowest common denominator? If you bet big and win, you clean up. But if you bet big and Starship has a problem or is more expensive than you thought, the extra launch costs may kill you.
Quote from: TheRadicalModerate on 12/12/2022 02:02 amHowever, there's still a remaining question: Because the likely crop of medium-to-heavy, non-refuelable launchers will give you 12-15t of prop to NRHO, and a Starship tanker might give you as much as 530t with full refueling, do you bias your design for higher performance and assume a large prop load, or do you design for the lowest common denominator? If you bet big and win, you clean up. But if you bet big and Starship has a problem or is more expensive than you thought, the extra launch costs may kill you.What I'd do is attach some very large tanks to Gateway, and then have NASA pay anyone who can to deliver fuel to those tanks. If they do it for cheap/kg, they get more profit, otherwise, they get less profit. Landers can refuel at Gateway (logical, but NASA would have to sell them fuel), and the amount of fuel delivered per tanker is no longer a relevant part of the lander's design nor operations. It also makes it easier to evntually *siphon* lunar or other extraterrestrial fuel into the system.
What the hell is Boeing doing on National Team Mark II?
larger tanks using a new manufacturing technique
Quote from: TheRadicalModerate on 03/05/2023 08:58 pmWhat the hell is Boeing doing on National Team Mark II?Quotelarger tanks using a new manufacturing technique...Now large hydrolox composite tanks is something Boeing has a fair bit of experience with and is something Blue presumably needs...
OK, but why are they are singled out as being part of the "team", and not just being a contractor?
Above quote is from Option A source selection and while the design there is probably a fair bit different from they have now, the principle of needing lighter tanks remains. Now large hydrolox composite tanks is something Boeing has a fair bit of experience with and is something Blue presumably needs. So in the best world I imagine that's what they're doing. Maybe a couple extra systems associated with that as well. Please don't give them an element Blue.https://www.nasaspaceflight.com/2022/03/boeing-all-composite-cryo-tank/I'm still hoping my architecture prediction is close to accurate.
Quote from: TheRadicalModerate on 03/05/2023 08:58 pmWhat the hell is Boeing doing on National Team Mark II?Quotelarger tanks using a new manufacturing techniqueAbove quote is from Option A source selection and while the design there is probably a fair bit different from they have now, the principle of needing lighter tanks remains. Now large hydrolox composite tanks is something Boeing has a fair bit of experience with and is something Blue presumably needs. So in the best world I imagine that's what they're doing. Maybe a couple extra systems associated with that as well. Please don't give them an element Blue.https://www.nasaspaceflight.com/2022/03/boeing-all-composite-cryo-tank/I'm still hoping my architecture prediction is close to accurate.
I believe you made an error in the ΔV values for the DAE LLO to LS and LS to LLO. 2,855 and 2,810 I think are your values for NRHO to LS and LS to NRHO, whereas it should be 2,060 and 2,015 because TE does NRHO to LLO. Although when I did it I got roughly similar propellant mass to NRHO (40 tons), but that was with 6 tons of propulsion stage masses instead of 0.88 and 2.97 tons. If you want to see my math and be baffled check out (and hopefully not find errors) . (please ignore the fact that it's a graphing software)This brings up the question of subLLO trajectory vs docking in LLO, because if you don't do either (like in the diagram); TE uses like 1/3 of the propellant the DAE does. SubLLO means that if DAE has issues starting engines you only have maybe an hour to solve before the rapid breaking manoeuvre occurs. Docking introduces LLO mission critical docking. I naturally lean towards subLLO because that's the first one I thought of, but docking could easily be safer (and better mass wise). alt mathIt is certainly more mass to NRHO. But if you have a fully reusable launch solution; more dumb propellant mass to NRHO is probably cheaper than the expendable hardware. The ultimate question here is how much do Blue believe in themselves? Because that's what dictates what's acceptable. This is the most mentally simulated I've been for a while so cheers for replying