The reason for Antares/Wallops was for cost/convenience. Paying for CCAFS/VAFB is one significant stopper.
Quote from: Space Ghost 1962 on 01/19/2016 08:58 pmThe reason for Antares/Wallops was for cost/convenience. Paying for CCAFS/VAFB is one significant stopper.This could depend on if NASA would like to "entice" another user for the VAB and 39B, as SLS will be only launching at a low rate and they've been wanting to make KSC a real spaceport. If NASA gave them a sweetheart deal, OrbATK may be ok with operating under the overhead/headaches of NASA. The VAB and SRB processing facilities at KSC could obviously handle large segments based on SLS boosters just fine. There's a couple of old MLP's available to be repurposed to handle the LV. It might not be a show stopper if OrbATK gets some sweet deal. Which is possible as NASA seems like they would like the optics of more than just an occasional SLS launch going out of KSC. (not counting 39A).Didn't SpaceX essentially get the lease for 39A for "free", just to take over maintenance and operation of it so it wouldn't be sitting there rotting?
... sell it to ULA's board.ULA stops working on Vulcan booster. Keeps working on ACES if they want. Atlas survives on a diet of Commercial Crew/Cargo flights, NASA science, and a few commercial payloads.OrbATK's latest version of "The Stick" becomes reality and replaces Delta IV. Flies a few times a year as "assured access." NASA and DOD are happy because it keeps the solid motor lines running.
Here's a notional EELV Medium and Heavy solution, using solid motors that are roughly the size of a 1.5-segment RSRM from ATK's motor catalog. Assume for this exercise a 193.5 tonne gross "common booster stage" (CBS), which may or may not comprise one or two "common booster segments". Assume the following.CBS has a 0.92 propellant mass fraction. CBS has 263 sec average ISP as a sea-level launch stage.CBS has 290 sec ISP as an air-start stage.A BE3U-powered LH2/LOX upper stage with a 440 sec ISP and a 0.90 propellant mass fraction. It would be loaded with around 50 tonnes propellant.Payload to 11,750 m/s for the in-line vehicle (essentially GTO x 28 deg) would be 6.5 metric tons (tonnes) for a GLOW of 451 tonnes.A Heavy would be boosted by two side-mounted motors with the center motors both air-lit. It could do 6 tonnes to GEO for a GLOW of about 870 tonnes. The rockets might stand 56 meters (182 feet) plus or minus, generally the same height as Atlas 5 and shorter than Falcon 9 or Delta 4 Heavy. 20 meters shorter than Ares 1. - Ed Kyle
I think you are correct with core, but strap ons will be GEM63XL, assume 6.
Where is the demand for this rocket??? Build it and they will come???
Ah, 4 stages for the heavy.Is 11.75km/s the total delta v for the medium version? I don't quite get to 6.5t with the given specs.
Quote from: Oli on 01/22/2016 06:38 amAh, 4 stages for the heavy.Is 11.75km/s the total delta v for the medium version? I don't quite get to 6.5t with the given specs.Yes. I may have "rounded" the numbers presented. My spreadsheet numbers were as follows for the Medium.S1 178.0/193.5 tonnes ISPavg= 263 Delta-v=1298.9 m/sS2 178.0/193.5 tonnes ISPavg= 290 Delta-v=3434.6 m/sS3 48.8/55.2 tonnes ISP=440 Delta-v = 7022.3 m/sTotal Delta-v = 11755.8 m/sI have a 2.5 tonne fairing during the first stage burn.All wild guesswork, of course! - Ed Kyle
Quote from: edkyle99 on 01/22/2016 01:55 pmQuote from: Oli on 01/22/2016 06:38 amAh, 4 stages for the heavy.Is 11.75km/s the total delta v for the medium version? I don't quite get to 6.5t with the given specs.Yes. I may have "rounded" the numbers presented. My spreadsheet numbers were as follows for the Medium.S1 178.0/193.5 tonnes ISPavg= 263 Delta-v=1298.9 m/sS2 178.0/193.5 tonnes ISPavg= 290 Delta-v=3434.6 m/sS3 48.8/55.2 tonnes ISP=440 Delta-v = 7022.3 m/sTotal Delta-v = 11755.8 m/sI have a 2.5 tonne fairing during the first stage burn.All wild guesswork, of course! - Ed KyleHmm...gives me 5.51t to GTO...