Quote from: Jim on 05/01/2014 02:30 amQuote from: Prober on 05/01/2014 02:28 amSorry ,Ed don't think you thinking big enough .....this is the direction they might be going with Antares as the Center core.Huh? That is an SLS competitor and not EELV competitor. They aren't going in that directionThere is always old Stumpy:http://forum.nasaspaceflight.com/index.php?topic=26476.0
Quote from: Prober on 05/01/2014 02:28 amSorry ,Ed don't think you thinking big enough .....this is the direction they might be going with Antares as the Center core.Huh? That is an SLS competitor and not EELV competitor. They aren't going in that direction
Sorry ,Ed don't think you thinking big enough .....this is the direction they might be going with Antares as the Center core.
Puts training hat on: Gives you a rough idea on some of the new ways to do things. These guys at Dynetics are an impressive lot.http://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/ Jon you think the F-1 is more complex than the AJ-26 or about even?Understand and agree with your point on Easy.....no project is really easy. Hope I didn't give the wrong impression.
yep, a couple of 3 segment solids with a single Antares core could be a new launcher and revenue stream.
Quote from: MP99 on 05/02/2014 10:20 amI know Pegasus II is intended to be developed for StratoLaunch. Is there a chance they'll now develop it as Antares replacement (perhaps with a larger 2nd stage), then have a mature LV ready to integrate with the carrier plane when it's ready? Cheers, MartinI wondered why they might have two LV's with similar performance. But given Ed's observations about potential issues with both engines and the Antares core, I'm wondering if the plan is to simply replace Antares with Pegasus II? They wouldn't need a launch facility for it. But it sounds like the Statolaunch aircraft won't be ready to fly until 2016? With the first launch from it not until 2018? (per wikipedia, for what that's worth). Are there enough Antares cores and engiens to get to 2018? Or might they be looking at ground launching Pegasus II from Wallops or somewhere prior to that, to maintain Cygnus until Statolaunch is ready?
I know Pegasus II is intended to be developed for StratoLaunch. Is there a chance they'll now develop it as Antares replacement (perhaps with a larger 2nd stage), then have a mature LV ready to integrate with the carrier plane when it's ready? Cheers, Martin
http://aviationweek.com/blog/orbital-eying-atk-solid-propulsion-system-antares-first-stage-1?sfvc4enews=42&cl=article_5
Quote from: Prober on 05/02/2014 04:51 pmyep, a couple of 3 segment solids with a single Antares core could be a new launcher and revenue stream.Nope, it won't. It can't be at wallops.
Well, it looks like Pegasus II will get over 6mt to LEO. That will beat out Antares 5mt to LEO.
So perhaps they intend for Pegasus II to replace Antares if things go south with Antares cores and engines, and if they get a renewed CRS contract, they move Cygnus to Pegasus II?
Lobo, I think you are right that they could be using a lot of the Pegasus II to make a land launch vehicle to replace Antares. That could be a single solid core version and the solid tri-core version with a liquid US. Land launch single core would have less than 13,500lb to LEO.The land launch version could be ready sooner than 2018 if funded.I would expect them to replace the RL-10's at some point with the NGE to lower cost.
Here's my guess for a composite solid motor Antares, including a growth version for CRS-2 missions. Replacing the Castor 30XL third stage of the growth version with an equal mass liquid hydrogen stage gets 4.8 tonnes to GTO (GEO-1,500 m/s) or 3.1 tonnes to escape velocity, or maybe more than 12 tonnes to LEO.For the growth version, I assumed essentially equal motors for the first two stages, similar to Athena 2, Minotaur 6, Shavit-3, etc. - Ed Kyle
Quote from: edkyle99 on 05/01/2014 12:29 amHere's my guess for a composite solid motor Antares, including a growth version for CRS-2 missions. Replacing the Castor 30XL third stage of the growth version with an equal mass liquid hydrogen stage gets 4.8 tonnes to GTO (GEO-1,500 m/s) or 3.1 tonnes to escape velocity, or maybe more than 12 tonnes to LEO.For the growth version, I assumed essentially equal motors for the first two stages, similar to Athena 2, Minotaur 6, Shavit-3, etc. - Ed Kyle Ed,In your concepts here, are your solid boosters based on what Pegasus II will have? The first being a smaller 2nd stage, and the 2nd concept being two equally sized stages. Are those the size of Pegasus II 1st stages? Or are those based on SLS advanced booster segs? Are those two segments the same size? Or just the same diameter, but different lengths?
Have to make equal comparisons. Antares 130 (with Castor 30XL), which will fly this year, is rated for more than 6 tonnes to 200 km x 38 deg. It can also lift more than 5.5 tonnes to 200 km x 51.6 deg (ISS inclination). We don't know, I think, what inclination applies to the 6 tonne Stratolauncher number, though a lower than ISS inclination was probably given. It likely lifts 5 to 5.5 tonne to an ISS inclination orbit.Also, Antares does 6 tonnes with an existing solid motor upper stage while Stratolaunch requires an RL10 liquid hydrogen upper stage to make that number. Imagine what Antares could do with an LH2 stage! Antares can grow. Stratolaunch can't, due to its air launch platform limited mass.
No, for the reasons stated above. The follow-on CRS-2 contract will require even more payload than Antares 130 will provide. Stratolaunch is already out of the running for that payload.
Quote from: edkyle99 on 05/02/2014 05:23 pmHave to make equal comparisons. Antares 130 (with Castor 30XL), which will fly this year, is rated for more than 6 tonnes to 200 km x 38 deg. It can also lift more than 5.5 tonnes to 200 km x 51.6 deg (ISS inclination). We don't know, I think, what inclination applies to the 6 tonne Stratolauncher number, though a lower than ISS inclination was probably given. It likely lifts 5 to 5.5 tonne to an ISS inclination orbit.Also, Antares does 6 tonnes with an existing solid motor upper stage while Stratolaunch requires an RL10 liquid hydrogen upper stage to make that number. Imagine what Antares could do with an LH2 stage! Antares can grow. Stratolaunch can't, due to its air launch platform limited mass.Ahhh, ok, thanks for the clarification. But do you think Antares could be going away with the Russian/Ukranian issues, and with OSC's access to big solids now? As you said, could they do an "Antares II" (which would actually look closer to a "Taurus II", ironically) with all solids, as in your concepts, and then develop a common hydrolox upper stage which could be used on Pegasus II or Antares II?Quote from: edkyle99 on 05/02/2014 05:23 pmNo, for the reasons stated above. The follow-on CRS-2 contract will require even more payload than Antares 130 will provide. Stratolaunch is already out of the running for that payload.I suppose that would beg the question, why do Stratolaunch at all? Convert the Antares pad to "Antares II". It'd have growth option as Stratolaunch doesn't. And probably more simple logistics of a fixed pad vs. a flying one. Or is launching out of Wallops too big of a penalty for GTO payloads vs Statolaunch which can fly south for better trajectories?
Nope, it won't. It can't be at wallops.
Quote from: Jim on 05/02/2014 04:57 pmQuote from: Prober on 05/02/2014 04:51 pmyep, a couple of 3 segment solids with a single Antares core could be a new launcher and revenue stream.Nope, it won't. It can't be at wallops.who said anything about wallops?
Quote from: Lobo on 05/02/2014 01:13 amThe thing is, they already have this class of LV with Antares and will have with Pegasus II. So not sure they'd develop another LV in that class, which the two solid concepts LV's would be.My premise is that Orbital ATK already must develop something to replace the existing Antares first stage, simply due to the limited number of NK-33 engines. - Ed Kyle
The thing is, they already have this class of LV with Antares and will have with Pegasus II. So not sure they'd develop another LV in that class, which the two solid concepts LV's would be.
Quote from: Prober on 05/02/2014 04:39 pmPuts training hat on: Gives you a rough idea on some of the new ways to do things. These guys at Dynetics are an impressive lot.http://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/ Jon you think the F-1 is more complex than the AJ-26 or about even?Understand and agree with your point on Easy.....no project is really easy. Hope I didn't give the wrong impression. And you are over hyping Dynetics, they aren't that impressive. Just another HSV local contractor
Quote from: edkyle99 on 05/02/2014 03:21 amQuote from: Lobo on 05/02/2014 01:13 amThe thing is, they already have this class of LV with Antares and will have with Pegasus II. So not sure they'd develop another LV in that class, which the two solid concepts LV's would be.My premise is that Orbital ATK already must develop something to replace the existing Antares first stage, simply due to the limited number of NK-33 engines. - Ed KyleFor throw out the idea Friday... Seems everyone has focused on the AJ-26 - NK-33 and forgotten this gem.Don't forget the NK-43! " The NK-43 is similar to the NK-33, but is designed for an upper stage, not a first stage. It has a longer nozzle, optimized for operation at altitude, where ambient air pressure is low or perhaps zero. This gives it a higher thrust and specific impulse, but makes it longer and heavier."This is idea would need development for the 2nd stage (Like the Hawthorne boys) but for Antares.