A BE-3 based upper stage with enough propellant may only need the first stage SRB for LEO missions.A Castor 1200 with a two BE-3U upper stage should be good for around 10,000kg on the low end I made a lot of conservative assumptions based on the shuttle RSRM and S-IVB mass fractions and assumed the BE 3-U has an ISP of around 435 though the engine can probably do better than this.Everything sized around the Castor 600 would be about 5tons.
OATK wants to use their own solids as much as possible, not want to buy liquid engines from other companies just because it's possible.What might make sense is to always have solid first and second stage. Then have two different third stages, solid for LEO and (single) BE-3U based for HEO.
There have been several DLR studies for expendable rockets with a solid first stage and cryogenic upperstage. One of the studies: VENUS (VEga New Upper Stage) studied multiple configurations for future vega rockets. The VEGA-F configuration used a P120-P160 first stage and a Vince powered upperstage. The conclusion with that configuration was that the acceleration levels would be very high, because the 2th stage + payload & fairing are very light (<40mT).That's why I don't think a configuration with Castor600 or Castor1200 and a cryogenic upper-stage would work.Because BE-3U (530kN [120k lbf] in vacuum) is roughly 3x as powerful as Vince (180kN [40 470 lbf], the cryogenic upper-stage could be much larger and heavier. Thus I think that a Castor 300 + enlarged Cryostage could work, but the cryo stage wouldn't be the same stage as for the other NGL configurations.Quote from: hkultala on 11/08/2017 06:17 amOATK wants to use their own solids as much as possible, not want to buy liquid engines from other companies just because it's possible.What might make sense is to always have solid first and second stage. Then have two different third stages, solid for LEO and (single) BE-3U based for HEO.I agree with this, with the side note that two different liquid upper-stages; deep cryo (LOX LH2) and soft cryo (LOx RP-1), could also bring benefits. (A LOxLCH4 / LOxLC3H8 cryo stage would be even beter).I think that two different lengths of cryogenic stages could work economically. But OATK want's to use their solids.
Surprising news! OrbitalATK is considering the AerojetRocketdyne RL10 or ArianeGroup Vinci rocket engine for its Next Generation Launcher upper stage after rejecting Blueorigin's BE-3U. Decision expected in Q1 2018. http://aviationweek.com/awinspace/orbital-atk-pick-upper-stage-engine-ngl
Quote from: Rik ISS-fan on 11/08/2017 09:30 amThere have been several DLR studies for expendable rockets with a solid first stage and cryogenic upperstage. One of the studies: VENUS (VEga New Upper Stage) studied multiple configurations for future vega rockets. The VEGA-F configuration used a P120-P160 first stage and a Vince powered upperstage. The conclusion with that configuration was that the acceleration levels would be very high, because the 2th stage + payload & fairing are very light (<40mT).That's why I don't think a configuration with Castor600 or Castor1200 and a cryogenic upper-stage would work.Because BE-3U (530kN [120k lbf] in vacuum) is roughly 3x as powerful as Vince (180kN [40 470 lbf], the cryogenic upper-stage could be much larger and heavier. Thus I think that a Castor 300 + enlarged Cryostage could work, but the cryo stage wouldn't be the same stage as for the other NGL configurations.Quote from: hkultala on 11/08/2017 06:17 amOATK wants to use their own solids as much as possible, not want to buy liquid engines from other companies just because it's possible.What might make sense is to always have solid first and second stage. Then have two different third stages, solid for LEO and (single) BE-3U based for HEO.I agree with this, with the side note that two different liquid upper-stages; deep cryo (LOX LH2) and soft cryo (LOx RP-1), could also bring benefits. (A LOxLCH4 / LOxLC3H8 cryo stage would be even beter).I think that two different lengths of cryogenic stages could work economically. But OATK want's to use their solids.An upper stage properly sized for the BE3-U would be about 60% the size of a S-IVB but it can throttle deeply so in theory could be made to work on a smaller stage but you'd have a high mass penalty of a too large engine.The RL-10 or Vinci looks like the best option though I wonder could a couple of Rutherfords work for a third stage?
The Vinci option maybe there as bargaining chip against AJR. Has good reliability record and built by allies so DoD certification may not be big issue. The NGLV will be competing with Ariane 6 for commercial launches, not sure how Ariane Aerospace view that.
The ESA itself is not a civilian agency. It is an agency for peaceful purposes and may have programmes with a security component. If and when Europe needs space as an enabling tool for its security and defence policy, ESA will be prepared to develop the required programmes.”
Rutherfords are not exactly Hydrolox engines. At least so far.An argument for Vinci over RL10 would be to offer a dissimilar engine that is flying a lot (with someone else). Taking the backup launcher idea and running with it.
Reposted:Quote from: Mike Jones on 12/13/2017 09:48 pmSurprising news! OrbitalATK is considering the AerojetRocketdyne RL10 or ArianeGroup Vinci rocket engine for its Next Generation Launcher upper stage after rejecting Blueorigin's BE-3U. Decision expected in Q1 2018. http://aviationweek.com/awinspace/orbital-atk-pick-upper-stage-engine-nglWonder what Orbital saw in Blue's engine that they didn't like? Does this reduce Blue's chances on Vulcan, too?
Quote from: TrevorMonty on 12/14/2017 03:52 amThe Vinci option maybe there as bargaining chip against AJR. Has good reliability record and built by allies so DoD certification may not be big issue. The NGLV will be competing with Ariane 6 for commercial launches, not sure how Ariane Aerospace view that.The fact that Vinci is built by allies of the USA does exactly nothing to aid certification for US NSS use: from a USA point-of-view it is a foreign-designed, -built and -tested engine.What also won't help is that Vinci is developed exclusively with ESA money. ESA might object to Vinci being used on a US launcher for US NSS purposes. Quote from: ESA Director GeneralThe ESA itself is not a civilian agency. It is an agency for peaceful purposes and may have programmes with a security component. If and when Europe needs space as an enabling tool for its security and defence policy, ESA will be prepared to develop the required programmes.” Additionally: NASA was initially interested in using Vinci on the EUS for SLS (2014). But that plan went nowhere when NASA and ESA couldn't agree on the specific terms-of-use and the general certification requirements for Vinci.So, what makes people think that the certifying agencies for US NSS launches will be able to come to an agreement with ESA?
BTW IIRC neither BE-3 or Vince has any flight history.
Quote from: woods170 on 12/14/2017 09:50 amSo, what makes people think that the certifying agencies for US NSS launches will be able to come to an agreement with ESA?OA wouldn't even consider Vinci if they didn't think there was good chance both parties would approve it. They went though same process with Liberty before it was shelved.
So, what makes people think that the certifying agencies for US NSS launches will be able to come to an agreement with ESA?
Quote from: john smith 19 on 12/14/2017 11:14 amBTW IIRC neither BE-3 or Vince has any flight history.No flight history, true, but Vinci has gone through extensive test firings and flight-ready engines are in production now.
My bet is on OATK down-selecting to RL10. It fits "build American, fly American".
This is like Liberty Launcher Lite?
My guess is that the reason for this engine change is the same reason that drove ULA toward Centaur 5. The NGL design team, preparing to respond to the EELV RFP, found that BE-3U didn't pass muster. - Ed Kyle