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#620
by
MP99
on 16 Aug, 2015 17:06
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I've noticed that the article did mentioned the 230 and 330 cores. I understand that the 230 are the old cores, retrofitted with an under throttled RD-181. And the 330 are the full thrust cores.
Playing the "rocket lego" game...
RD-181 is throttled because the S1 tanks are too small to carry the optimum prop load.
As an alternative to stretching the tanks, how would the performance compare if another solid stage (another Castor 30?) was added instead? Would anything in OATK's current inventory be close to optimal?
(Stretched tank makes all sort of sense, but I'm just interested.)
Cheers, Martin
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#621
by
Space Ghost 1962
on 16 Aug, 2015 20:33
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Nope, no appropriate Lego.
The 30XL does what the prior Antares needed, and the next Antares to fly won't be able to better it.
Further down the road with the 300 series, you could stretch to an "XXL" of some sort, but it would be likely that the trades won't buy all that much, the limitation being the iSP of such stages. Which is unfortunate as the ATK side of OrbATK could use such a project about now.
Orbital desired a hydrolox second stage, much like Atlas/Vulcan does, for the same reasons. Look to the sources of these, and the cost of such stage development/deployment being recovered by current manifest flyout as the limitation for uprating to a LRE higher iSP second stage. Somehow, acquiring by similar means LRE second stage as they did/do first stage, might be quick but add additional liabilities they might not want at the moment.
Nice to see they are mounting actual flight hardware with that pic. Seems like an aggressive posture for RTF that they need about now. The only way they could have ever done this so fast was by merchant supply of a LRE, and the Russians have a lock on the market for ones of that scale right now. It is unclear to me if that is going to change any time soon, even with the dread pirate Bezos involved
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#622
by
baldusi
on 16 Aug, 2015 21:28
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[...]
Nice to see they are mounting actual flight hardware with that pic. Seems like an aggressive posture for RTF that they need about now. The only way they could have ever done this so fast was by merchant supply of a LRE, and the Russians have a lock on the market for ones of that scale right now. It is unclear to me if that is going to change any time soon, even with the dread pirate Bezos involved
You mean that the Russians were the only ones to keep investing in new staged combustion engines in a somewhat constant manner. But the Indians are six to eight months from starting test firing of an equivalent engine, the SCE-200.
Regarding the Antares 300 series, it will be conditional on Orbital getting the CRs-2 contract. A new solid upper stage will probably enable them to get 4,000kg to the station if stretch a bit the Cygnus or widen it a bit more. But their current fairing is only 3.9m, whith 3.5m internal diameter. Still 20cm narrower than the 3.7m industry standard for 4m fairing. So a new fairing (done by ATK) and a new solid upper stage would be a low risk, revenue intergating move that would be self payed by the CRS-2 contract.
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#623
by
MP99
on 16 Aug, 2015 22:46
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Nope, no appropriate Lego.
The 30XL does what the prior Antares needed, and the next Antares to fly won't be able to better it.
Further down the road with the 300 series, you could stretch to an "XXL" of some sort, but it would be likely that the trades won't buy all that much, the limitation being the iSP of such stages. Which is unfortunate as the ATK side of OrbATK could use such a project about now.
RD-181 is de-rated on 2xx. They can turn the engines up to 11 on the 3xx because they'll add more mass to S1.
I was just wondering what performance you'd get if you retained the 200 S1, but assigned the extra GTOW to an additional solid stage. Yes, it has a lower Isp, but it also stages a lot of mass away.
I realise this isn't a practical suggestion - more expensive, more complicated, greater risk. Just NSF legos.
Cheers, Martin
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#624
by
TrevorMonty
on 16 Aug, 2015 23:36
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For future CRS-2 missions the 300 with Castor 30XL is probably all that is needed. If Orbital want to go after commercial GTO launches or NASA BLEO missions the Antares 300 will need a LHx upper stage.
For DOD missions they will need the LHx US plus a domestically powered booster. A solid booster (ATK Liberty) is not an option for Wallops according to our resident experts. The BE4 would also not be an option given ULA are helping fund it. The AR1 is a possibility but anything using it will not fly to around 2020-21.
The Ariane 6 configuration may work for Wallops.
2-3 x BE3 booster with 2-4 SRBs. This would utilise ATK SRB capabilities. There are no prices for BE3 but <$5M is probably realistic due its extensive use of additive manufacturing.
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#625
by
baldusi
on 17 Aug, 2015 17:36
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[...]
RD-181 is de-rated on 2xx. They can turn the engines up to 11 on the 3xx because they'll add more mass to S1.
I was just wondering what performance you'd get if you retained the 200 S1, but assigned the extra GTOW to an additional solid stage. Yes, it has a lower Isp, but it also stages a lot of mass away.
[...]
From what I understand, 100 cores were designed for certain stresses. Increasing the thrust 30% and adding more weight on top, increasses the compression stress by 30%+proportion of weight increase in upper stage/payload. Then you have things that a higher T/W means a higher MaxQ. And you have to do the dynamic (i.e. POGO) analysis. I've heard that on the 200 they tried to keep the fly profile as close to the 100 as possible. That's why I believe that any big changes will happen on the 300. If I'm counting right, they will have just 1 200 core left after the current CRS-1 finishes (if they get no further extensions).
So, Antares 300 IFF CRS-2. Is that simple. And if they do, I've seen a presentation of Orbital for a four segment Cygnus, which had 33m³. So, if they can get the fill efficiency of an Enhanced Cygnus (130kg/m³), then they could carry 4,250kg per mission if they could lift it. Since I estimate Super Cygnus to mass 350kg over the Enhanced, I would guess that they would need 1,400kg over the Antares 230 to max out the performance. That's almost a 30% extra performance required of 330 to 230. I don't believe they could achieve that without a new upper stage.
But if they do, they could get 8.5tonnes in just two launches per year. If they went with a very low price of 70,000 USD/kg (SpaceX CRS-1 price was 80,000), they would still get almost 300M per flight or 600M per year. In five years they would have a revenue of 3B. I believe that's quite a penny and they will bid very aggressively.
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#626
by
Zed_Noir
on 18 Aug, 2015 05:39
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@baldusi
Maybe OrbATK can take a page from SpaceX. Offer Boeing a test flight of the Atlas V 402 lifting a 4 segment Cygnus to the ISS. In exchange for a reduced price Atlas V 402 launcher.
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#627
by
baldusi
on 18 Aug, 2015 18:20
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@baldusi
Maybe OrbATK can take a page from SpaceX. Offer Boeing a test flight of the Atlas V 402 lifting a 4 segment Cygnus to the ISS. In exchange for a reduced price Atlas V 402 launcher.
Boeing will validate the Atlas V 422 with the unmanned demonstration flight. And an Atlas V discount would have to be given by LM launch services. So it just doesn't makes much sense. It is true, though, that a 4 segment Cygnus would need a 5m fairing in the Atlas V, which will be a bit more expensive (I'd guess 15M to 20M extra for a 511 vs a 401). But the payload differential would probably more than make up for it.
In any case, OA apparently prefers to use its own launcher. If they wanted to play it safe, they would probably buy another Atlas V, launch first a 330, then the Atlas V, then the last remaining 230, and only then keep churning 330. Alternately, if 330 schedule is the riskiest part, they could launch 230, Atlas V, 330.
There's no point in validating the 4 segment Cygnus. They are very good at spacecrafts. But I remember that Thales Alenia had stated that they had used too much human rated requirements on the PCM that could be done away with (which would save mass and cost) if they had a big order. So I would expect a new PCM for CRS-2 anyways. How different? I don't know, but I couldn't discard a four segment.
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#628
by
Space Ghost 1962
on 18 Aug, 2015 20:13
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Note that:
a) four segment allows larger, less dense payloads to ISS irrespective of substantial mass increase
b) optional nature of 300 series payload increase means a choice against lowering cost AV/Vulcan
c) 300 series increase due to beyond NK-33/AJ-26 engine performance (both thrust and duration) can have follow-on complement with second stage upgrade increments
d) OA has not done enough missions (nor has SX) yet for spacecraft business to rely entirely on a sole LV.
e) OA has been attempting to "sell" exploration capabilities/missions based exactly on those Thales Alena human rated requirements supposedly to be abandoned.
There is a lot more here then appears on the surface. Also, there are underutilized parts of OA (and other firms) that can play into this too.
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#629
by
TrevorMonty
on 18 Aug, 2015 20:56
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Cygnus would need to be man rated especially when it is berthed with ISS.
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#630
by
sdsds
on 18 Aug, 2015 21:38
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Cygnus would need to be man rated especially when it is berthed with ISS.
Sorry, did I miss a memo or something? I would have written:
"We know Cygnus is already human rated because it has been berthed at ISS."
Note that:
e) OA has been attempting to "sell" exploration capabilities/missions based exactly on those Thales Alena human rated requirements supposedly to be abandoned.
Again, to what does this refer please? Has there been a report of someone abandoning human rating requirements?
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#631
by
Sam Ho
on 18 Aug, 2015 23:47
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But I remember that Thales Alenia had stated that they had used too much human rated requirements on the PCM that could be done away with (which would save mass and cost) if they had a big order. So I would expect a new PCM for CRS-2 anyways. How different? I don't know, but I couldn't discard a four segment.
The comments I recall from Thales Alenia said that they could reduce the cost of the PCM for a big CRS-2 order, but it wasn't due to relaxing human rating. Rather, it was from reducing on-orbit lifetime.
But with a little advance planning and a sizable order, Quaglino said, a CRS 2 batch could do without some of the cabling and other components that were required for units that would spend years attached to the space station.
http://spacenews.com/39934thales-alenia-space-exec-identifies-ways-to-save-on-next-cygnus-order
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#632
by
Space Ghost 1962
on 19 Aug, 2015 02:19
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Note that:
e) OA has been attempting to "sell" exploration capabilities/missions based exactly on those Thales Alena human rated requirements supposedly to be abandoned.
Again, to what does this refer please? Has there been a report of someone abandoning human rating requirements?
As Sam Ho above mentions, time on orbit.
In a nutshell, ISS components have a much greater set of requirements for lifetime on orbit beyond visiting vehicles.
The point I was raising, was that, say if you were going to do a longer "mini space station", or say part of the L1/2 Gateway, you'd have to meet such requirements.
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#633
by
Zed_Noir
on 19 Aug, 2015 06:57
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@baldusi
Maybe OrbATK can take a page from SpaceX. Offer Boeing a test flight of the Atlas V 402 lifting a 4 segment Cygnus to the ISS. In exchange for a reduced price Atlas V 402 launcher.
Boeing will validate the Atlas V 422 with the unmanned demonstration flight. And an Atlas V discount would have to be given by LM launch services. So it just doesn't makes much sense. It is true, though, that a 4 segment Cygnus would need a 5m fairing in the Atlas V, which will be a bit more expensive (I'd guess 15M to 20M extra for a 511 vs a 401). But the payload differential would probably more than make up for it.
...
There's no point in validating the 4 segment Cygnus. They are very good at spacecrafts. But I remember that Thales Alenia had stated that they had used too much human rated requirements on the PCM that could be done away with (which would save mass and cost) if they had a big order. So I would expect a new PCM for CRS-2 anyways. How different? I don't know, but I couldn't discard a four segment.
There seems to be a misunderstanding. My point is that you sent up a dual engine Centaur with the 4 segment Cygnus to the ISS. As precursor to the Atlas V 422 flight with the much more expensive CST-100. To validate the new unflown dual engine Centaur design, not the Thales Alenia PCM. Which I agree with you, needs no new validation. Maybe we will get a full size CBM hatch on top of the 4 segment PCM.
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#634
by
russianhalo117
on 20 Aug, 2015 00:18
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@baldusi
Maybe OrbATK can take a page from SpaceX. Offer Boeing a test flight of the Atlas V 402 lifting a 4 segment Cygnus to the ISS. In exchange for a reduced price Atlas V 402 launcher.
Boeing will validate the Atlas V 422 with the unmanned demonstration flight. And an Atlas V discount would have to be given by LM launch services. So it just doesn't makes much sense. It is true, though, that a 4 segment Cygnus would need a 5m fairing in the Atlas V, which will be a bit more expensive (I'd guess 15M to 20M extra for a 511 vs a 401). But the payload differential would probably more than make up for it.
...
There's no point in validating the 4 segment Cygnus. They are very good at spacecrafts. But I remember that Thales Alenia had stated that they had used too much human rated requirements on the PCM that could be done away with (which would save mass and cost) if they had a big order. So I would expect a new PCM for CRS-2 anyways. How different? I don't know, but I couldn't discard a four segment.
There seems to be a misunderstanding. My point is that you sent up a dual engine Centaur with the 4 segment Cygnus to the ISS. As precursor to the Atlas V 422 flight with the much more expensive CST-100. To validate the new unflown dual engine Centaur design, not the Thales Alenia PCM. Which I agree with you, needs no new validation. Maybe we will get a full size CBM hatch on top of the 4 segment PCM.
DEC has flown on select misisons of Atlas III anf V Families. They build one DEC every year to facilitate training on DEC config and buildup. DEC is then disassembled and rebuilt back to the standard SEC config. First DEC assembly with RL10C-1 is planned for validation and other testing this and next year
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#635
by
Zed_Noir
on 20 Aug, 2015 02:03
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There seems to be a misunderstanding. My point is that you sent up a dual engine Centaur with the 4 segment Cygnus to the ISS. As precursor to the Atlas V 422 flight with the much more expensive CST-100. To validate the new unflown dual engine Centaur design, not the Thales Alenia PCM. Which I agree with you, needs no new validation. Maybe we will get a full size CBM hatch on top of the 4 segment PCM.
DEC has flown on select misisons of Atlas III anf V Families. They build one DEC every year to facilitate training on DEC config and buildup. DEC is then disassembled and rebuilt back to the standard SEC config. First DEC assembly with RL10C-1 is planned for validation and other testing this and next year
AFAIK the DEC have not flown on any Atlas V mission so far. There are hardware changes between the Atlas II/Atlas III and the Atlas V versions of the DEC AIUI. So the forthcoming DEC design with the RL-10C have no flight history.
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#636
by
russianhalo117
on 20 Aug, 2015 02:51
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There seems to be a misunderstanding. My point is that you sent up a dual engine Centaur with the 4 segment Cygnus to the ISS. As precursor to the Atlas V 422 flight with the much more expensive CST-100. To validate the new unflown dual engine Centaur design, not the Thales Alenia PCM. Which I agree with you, needs no new validation. Maybe we will get a full size CBM hatch on top of the 4 segment PCM.
DEC has flown on select misisons of Atlas III anf V Families. They build one DEC every year to facilitate training on DEC config and buildup. DEC is then disassembled and rebuilt back to the standard SEC config. First DEC assembly with RL10C-1 is planned for validation and other testing this and next year
AFAIK the DEC have not flown on any Atlas V mission so far. There are hardware changes between the Atlas II/Atlas III and the Atlas V versions of the DEC AIUI. So the forthcoming DEC design with the RL-10C have no flight history.
Last was in 2003 and was a flight test of the Atlas V DEC version. PDR was in 2013 and CDR was in 2014. Firing tests for CCP are to be checked off this year.160+ DEC flights to date
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#637
by
ArbitraryConstant
on 21 Aug, 2015 19:14
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Orbital desired a hydrolox second stage, much like Atlas/Vulcan does, for the same reasons. Look to the sources of these, and the cost of such stage development/deployment being recovered by current manifest flyout as the limitation for uprating to a LRE higher iSP second stage. Somehow, acquiring by similar means LRE second stage as they did/do first stage, might be quick but add additional liabilities they might not want at the moment.
This could get interesting over the next few years, the manufacturing technology now allows 3D printing the entire combustion chamber for smaller sized engines, and I'd expect this to promote engine development.
I don't expect any of the pressure fed or electric fed examples to show amazingly high performance but 3D printing the entire combustion chamber with integrated cooling channels sounds like a dream for someone wanting to do expander. Also methane should be able to do FRSC, the Russians have several extremely good SC engines for upper stages that have served them very well.
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#638
by
wtrix
on 03 Sep, 2015 11:16
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#639
by
Mader Levap
on 05 Sep, 2015 17:43
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Not surprising, considering these two countries have de facto undeclared war with each other.
Feasibility of their proposition is, of course, different story.
