Quote from: MATTBLAK on 09/29/2013 06:22 amThat Pyrios/Delta is one looooonngg, skinny dude, eh? Side-mount it!
That Pyrios/Delta is one looooonngg, skinny dude, eh?
Quote from: TomH on 09/27/2013 06:34 pm I am curious to know whether DUUS is appropriately sized such that it could serve as the US on top of Pyrios, and if not whether slight modifications could make it work.It could, but it would not be efficient. The relatively limited thrust of DUUS (about 55 tonnes max) would limit how much propellant could be loaded onto the stage (offloaded from the maximum 130 tonnes possible), which would reduce payload. My estimate is that the LEO payload of a "Pyrios/DUUS" would be something like 25 tonnes, assuming a minimum DUUS T/W of 0.4, which would require a 40 tonne propellant offload. Now if more thrust could be provided (six engines?) the tanks could be full and LEO payload could easily surpass 30 tonnes. But, of course, this creates a new stage with added expense.
I am curious to know whether DUUS is appropriately sized such that it could serve as the US on top of Pyrios, and if not whether slight modifications could make it work.
But of course Saturn IB didn't have a Delta IV Heavy already flying. A Pyrios/DUUS must have a reason to exist, and with the performance numbers presented above I don't think it does.
He did mention the idea of switching out the engine cluster for a J-2X for this application, and having two versions of the stage. You'd have to change a lot, though...
Ed, as I mentioned above, the current DUUS concept looks like it could mount either four RL-10's, or two MB-60's, right? In following Tom's hypothetical, could the DUUS not be made to mount 2 or 4 MB-60's, as MB-60 really is about the same size as RL-10. Sort of like how ACES would be made to mount either two or four RL-10's? So just two MB-60's would be used on SLS, but four MB-60's could be used as a Pyrios US. That's 240klbs of thrust with very good ISP. Less thrust than J2X but better ISP. And I think four MB-60's would be about the same or less than a single J2X.
Sounds kinda like what I was thinking. It -could- be done, but there's really no reason for it. Even by adding DCSS on top of the DUUS you don't get much more performance than the D4H with RS-68A's. That Pyrios/D4 concept is interesting though. The "Manute Bol" Rocket. ;-). On another note, I started a new thread to explore other Pyrios LV concepts other than just Pyrios/DUUS. So as to not get OT on this thread.http://forum.nasaspaceflight.com/index.php?topic=32976.0I'd be curious to get Ed's input there. :-)
That was my only reason earlier in my comments about the need for it as "feasible". It's not feasible if there is no reason for it, even if it's technically a sound LV.
So the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO?
Quote from: clongton on 05/17/2018 10:52 amSo the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO??Falcon, Vulcan, New Glenn and maybe even Omega could launch Orion to LEO. A departure stage could be launched separately by any of those rockets as well.
Quote from: Oli on 05/18/2018 11:38 amQuote from: clongton on 05/17/2018 10:52 amSo the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO??Falcon, Vulcan, New Glenn and maybe even Omega could launch Orion to LEO. A departure stage could be launched separately by any of those rockets as well.Oli this is about a government-owned launch system. The US Gov will use commercial launchers for other things but definitely wants to maintain its own human launch capability. That's what this thread was predicated on - a US Gov owned and operated human launch system. NASA is ceding LEO to Commercial but want's it's own BLEO capability, including entering LEO to meet up with the BLEO mission hardware. This is CxP being resurrected.
Quote from: clongton on 05/18/2018 12:34 pmQuote from: Oli on 05/18/2018 11:38 amQuote from: clongton on 05/17/2018 10:52 amSo the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO??Falcon, Vulcan, New Glenn and maybe even Omega could launch Orion to LEO. A departure stage could be launched separately by any of those rockets as well.Oli this is about a government-owned launch system. The US Gov will use commercial launchers for other things but definitely wants to maintain its own human launch capability. That's what this thread was predicated on - a US Gov owned and operated human launch system. NASA is ceding LEO to Commercial but want's it's own BLEO capability, including entering LEO to meet up with the BLEO mission hardware. This is CxP being resurrected.Wouldn't it be faster and cheaper to use commercial to get to LEO (since commercial will be well-established there anyway) and use a USG owned and operated deep space transfer vehicle to go BLEO? E.g. Orion with a large refuelable hypergol stage, or bought and owned "off-the-shelf" technology similar to ACES/XUES.
Quote from: Oli on 05/18/2018 11:38 amQuote from: clongton on 05/17/2018 10:52 amSo the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO??Falcon, Vulcan, New Glenn and maybe even Omega could launch Orion to LEO. A departure stage could be launched separately by any of those rockets as well.Oli this is about a government-owned launch system. The US Gov will use commercial launchers for other things but definitely wants to maintain its own human launch capability.
The only viable way I see SLS actually being productive is through this radical change. I know it isn't going to happen because of the too numerous political and economic interests involved. But if those entities wanted it to work, they could make it work.I would forget advanced boosters, new RS-25s, upper stages, pad changes, man-rating iCPS. I would slightly downsize the SLS core, strengthen its walls, put J2-X engines on it and turn it into a single disposable massive high-energy upper stage. I would then pay SpaceX to launch this thing on top of BFB. You could easily send Orion with a lander to the moon. You could reprop the thing in LEO and send a mission to Mars. Boeing would still get its pork, AJR would get to build engines, SpaceX would get more income from using its giant booster. Only Orbital-ATK would lose out. (How close is Hatch to retirement?)Yes, it would mean redesign and more delays, but J2-X is done. Again, no more pad mods, no EUS to deal with, no man-rating iCPS, no tower mods, no advanced boosters, no RS-25E. Yes, you'd have flight control hardware and software integration headaches, but you'd have one single main stage to pay for and you'd get a lot more than 130 mT to LEO and real throw weight to BLEO. And you could probably do a lot more than one launch per year.But I know. Ain't gonna happen. If you want a high energy disposable US to deep space though, this would be one hell of a rocket. Isn't landing BFS on the moon a lot cheaper? Of course it is! But that doesn't send any pork to Boeing and AJR; this does.
In my research wrt the Dynetics proposed LRB for SLS I came across this thread. It's been a long time since anyone posted here and I considered starting a new thread to ask the question I do at the bottom but wasn't sure if that would be appropriate given that events have long since overtaken some of the basis of this thread. TomH was right - it kept going OT which is why, imo, nobody got to what was to be an obvious conclusion for the existence of this proposed vehicle; a Pyrios booster/1st stage and a DUUS. Quote from: edkyle99 on 09/28/2013 05:46 pmBut of course Saturn IB didn't have a Delta IV Heavy already flying. A Pyrios/DUUS must have a reason to exist, and with the performance numbers presented above I don't think it does.Quote from: Lobo on 09/30/2013 10:04 pmThat was my only reason earlier in my comments about the need for it as "feasible". It's not feasible if there is no reason for it, even if it's technically a sound LV.Ed and Lobo, as sharp as both of you are I'm surprised you both missed the obvious: it did have a purpose. It would be the CLV for Orion, in exactly the same manner as Ares-1 was to be the CLV for Ares-5. A lot of water has gone under the bridge since you guys wrote this and a lot of things have changed. But there is 1 thing that remains a perpetual problem for Orion; there are no USGov owned LVs capable of carrying it to LEO except SLS and ULA's DIVH. But DIVH is (1) not human rated and (2) is now being discontinued. It has become increasingly obvious to me that the USGov intends to maintain a government owned/operated launch system in spite of increasing commercial capabilities. The trouble is that SLS won't even fly once a year and when it does it is gawd-awful expensive. So if the USGov wants to fly Orion more often than that it needs a human rated launcher other than SLS. Pyrios with an appropriate upper stage was to be that launcher if it's existence could be justified as the LRB for SLS. That was Dynetics clear statement in their paper. Today that would take a political firestorm with ATK to make that happen but it is still an interesting thought.So the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO?