Looks like there's going to be an all solid motor launch vehicle from Orbital ATK.
Quote from: Rummy on 01/14/2016 04:32 pmLooks like there's going to be an all solid motor launch vehicle from Orbital ATK.Nope. The Stick Lives with BE-3U upper stage. Otherwise aka Blue Liberty.
OrbATK says "intermediate to heavy class family of EELVs capable of launching Air Force and other payloads" Return of the old Alliant Techsystems design?http://forum.nasaspaceflight.com/index.php?topic=19248.0
So, will it be like the solid motor Antares design Orbital-ATK was looking at last year, or something more like one of the Ariane 6 proposals? - Ed Kyle
Quote from: edkyle99 on 01/15/2016 04:33 pmSo, will it be like the solid motor Antares design Orbital-ATK was looking at last year, or something more like one of the Ariane 6 proposals? - Ed KyleSomething in between, perhaps? I'm thinking two solid stages topped by a 3rd HydroLox stage, powered by a BE-3U. The "intermediate to heavy class" part makes me think that this core could be flanked by two 1st stages as boosters for the "heavy" variant, thus making it similar to the Ariane 6 concept. But I could be off base.
They may use a combination of Ariane 6 P1B and P7C designs. Being able to dial up the performance by using strap on SRBs would allow one design to cover a range of missions from ISS cargo resupply to large GEO satellites. http://aviationweek.com/awin/cnes-asi-favor-solid-rocket-design-ariane-6
Solids are often touted as being potentially low cost. Has there been an example of a low-cost solid LV? The Minotaurs are cheap because they are secondhand. Titan wasn't cheap. Shuttle SRBs aren't cheap. Liberty's price apparently wasn't compelling. Pegasus wasn't cheap for its capability level. The strap-ons for Atlas and Delta don't appear to be all that cheap based on the price increments for them, and they already have more volume production than a launch vehicle would. What shining examples am I missing?And how ugly a statement about Orbital-ATK's confidence in the future of the current Antares does this make, to be looking to replace it with a design largely overlapping in performance?
So the answer is: "it depends".Are we competing with Antares, Atlas, Vulcan, Falcon? Ariane?The reason PPH was desirable was that you could scale modularly the solids, intended (mostly) to be one SRM used in perhaps up to 6 places (4+2). So the potential for high multiples of the same thing.So why was this ditched for A5 redux? Because the flight frequency did not support the costing. Perhaps if you had more than Ariane 5 flight frequency, and less motor cost, you might make it work. The thorn to that is F9R (if real threat) and your minimum 2 motors.If the point is competing with Atlas for like payloads, then the point is less about the lower two-three SRM's, and more about the US. Perhaps you'd want Centaur+ capabilities (don't forget the lower iSP of the solids it's launched from), and possibly a reusable stage, something that Tory Bruno seems to be chatting up more lately.
Solids are often touted as being potentially low cost. Has there been an example of a low-cost solid LV? The Minotaurs are cheap because they are secondhand. Titan wasn't cheap. Shuttle SRBs aren't cheap. Liberty's price apparently wasn't compelling. Pegasus wasn't cheap for its capability level. The strap-ons for Atlas and Delta don't appear to be all that cheap based on the price increments for them, and they already have more volume production than a launch vehicle would. What shining examples am I missing?
I tend to agree with TrevorMonty that we may see a big solid core stage or stages with optional GEM 63XL strap-on motors. The big questions are whether the core will use a segmented motor or motors, and one or two or three solid motor stages, etc. - Ed Kyle
Quote from: edkyle99 on 01/16/2016 02:26 amI tend to agree with TrevorMonty that we may see a big solid core stage or stages with optional GEM 63XL strap-on motors. The big questions are whether the core will use a segmented motor or motors, and one or two or three solid motor stages, etc. - Ed KyleAssuming that they do go for a big hydrolox upper with a BE-3Uen, what would make more sense? I think that either one or two solid stages would be enough, especially if they are planning on adding a flexible amount strap-on SRMs to the core. I'd be willing to guess one, but it seems that part of the wording in the contract does not point to that.