Which Atlas V configuration is this? 411? 412?
Here is a photo of a wind tunnel model. You can see two SRMs. I can't understand why ULA and NASA refuse to show the base of the aeroskirt. I doubt it is open, because hydrogen gas might accumulate, but since it extends down the side of the Centaur LH2 tank, I can't see how it could taper or close.It seems to me an unsettling design patch, late in the game. - Ed Kyle
Quote from: edkyle99 on 10/13/2016 03:45 pmHere is a photo of a wind tunnel model. You can see two SRMs. I can't understand why ULA and NASA refuse to show the base of the aeroskirt. I doubt it is open, because hydrogen gas might accumulate, but since it extends down the side of the Centaur LH2 tank, I can't see how it could taper or close.It seems to me an unsettling design patch, late in the game. - Ed KyleI wonder if there is a reverse taper upwards, as a stiffener, to the Centaur...
Quote from: Rocket Science on 10/13/2016 03:58 pmQuote from: edkyle99 on 10/13/2016 03:45 pmHere is a photo of a wind tunnel model. You can see two SRMs. I can't understand why ULA and NASA refuse to show the base of the aeroskirt. I doubt it is open, because hydrogen gas might accumulate, but since it extends down the side of the Centaur LH2 tank, I can't see how it could taper or close.It seems to me an unsettling design patch, late in the game. - Ed KyleI wonder if there is a reverse taper upwards, as a stiffener, to the Centaur...Maybe. It would have to connect to the Centaur forward skirt where the 500-series Centaur load reactor connects. There would also have to be provisions for Centaur venting, I think.It is going to separate after staging, kind of like a payload fairing. Another separation step added to the design. - Ed Kyle
New Boeing video, complete with the new skirt:https://twitter.com/BoeingDefense/status/786643807810879488
Quote from: edkyle99 on 10/13/2016 03:45 pmHere is a photo of a wind tunnel model. You can see two SRMs. I can't understand why ULA and NASA refuse to show the base of the aeroskirt. I doubt it is open, because hydrogen gas might accumulate, but since it extends down the side of the Centaur LH2 tank, I can't see how it could taper or close.It seems to me an unsettling design patch, late in the game. - Ed KyleThe first major delay of CST-100 (of roughly six months), as announced by Boeing last May, was mostly caused by the need to do this "design patch" and fix an overweight problem.And now, another slip of roughly six months because Boeing screwed up the lower dome of spacecraft number 2. Let's see, in the space of less than six months the first crewed mission of CST-100 has slipped almost a year.Ouch...Clearly, the Boeing way of doing things is not as beatific as some had claimed here.
Quote from: GWH on 10/13/2016 07:45 pmNew Boeing video, complete with the new skirt:https://twitter.com/BoeingDefense/status/786643807810879488Wow. Kudos to Boeing for ponying up for top-shelf animation.
My thoughts exactly. I doubt I've ever seen a render of such quality (judging mostly by the still frame). Moore's law, I guess... but still, somebody really wants it to be real.
Quote from: AnimatorRob on 10/13/2016 09:18 pmQuote from: GWH on 10/13/2016 07:45 pmNew Boeing video, complete with the new skirt:https://twitter.com/BoeingDefense/status/786643807810879488Wow. Kudos to Boeing for ponying up for top-shelf animation.My thoughts exactly. I doubt I've ever seen a render of such quality (judging mostly by the still frame). Moore's law, I guess... but still, somebody really wants it to be real.
Ugh. I can't wait for Vulcan.
Quote from: woods170 on 10/13/2016 07:14 pmQuote from: edkyle99 on 10/13/2016 03:45 pmHere is a photo of a wind tunnel model. You can see two SRMs. I can't understand why ULA and NASA refuse to show the base of the aeroskirt. I doubt it is open, because hydrogen gas might accumulate, but since it extends down the side of the Centaur LH2 tank, I can't see how it could taper or close.It seems to me an unsettling design patch, late in the game. - Ed KyleThe first major delay of CST-100 (of roughly six months), as announced by Boeing last May, was mostly caused by the need to do this "design patch" and fix an overweight problem.And now, another slip of roughly six months because Boeing screwed up the lower dome of spacecraft number 2. Let's see, in the space of less than six months the first crewed mission of CST-100 has slipped almost a year.Ouch...Clearly, the Boeing way of doing things is not as beatific as some had claimed here.Nor is cheap points scoring welcome here.
Quote from: mfck on 10/13/2016 11:14 pmQuote from: AnimatorRob on 10/13/2016 09:18 pmQuote from: GWH on 10/13/2016 07:45 pmNew Boeing video, complete with the new skirt:https://twitter.com/BoeingDefense/status/786643807810879488Wow. Kudos to Boeing for ponying up for top-shelf animation.My thoughts exactly. I doubt I've ever seen a render of such quality (judging mostly by the still frame). Moore's law, I guess... but still, somebody really wants it to be real.The rendering is great, the subject's appearance now... meah...
Quote from: Rocket Science on 10/14/2016 01:51 amQuote from: mfck on 10/13/2016 11:14 pmQuote from: AnimatorRob on 10/13/2016 09:18 pmQuote from: GWH on 10/13/2016 07:45 pmNew Boeing video, complete with the new skirt:https://twitter.com/BoeingDefense/status/786643807810879488Wow. Kudos to Boeing for ponying up for top-shelf animation.My thoughts exactly. I doubt I've ever seen a render of such quality (judging mostly by the still frame). Moore's law, I guess... but still, somebody really wants it to be real.The rendering is great, the subject's appearance now... meah... Sure. Meah is an understatement. It's ugly to a point where one starts to doubt its flight qualities
Quote from: Star One on 10/13/2016 09:32 pmQuote from: woods170 on 10/13/2016 07:14 pmQuote from: edkyle99 on 10/13/2016 03:45 pmHere is a photo of a wind tunnel model. You can see two SRMs. I can't understand why ULA and NASA refuse to show the base of the aeroskirt. I doubt it is open, because hydrogen gas might accumulate, but since it extends down the side of the Centaur LH2 tank, I can't see how it could taper or close.It seems to me an unsettling design patch, late in the game. - Ed KyleThe first major delay of CST-100 (of roughly six months), as announced by Boeing last May, was mostly caused by the need to do this "design patch" and fix an overweight problem.And now, another slip of roughly six months because Boeing screwed up the lower dome of spacecraft number 2. Let's see, in the space of less than six months the first crewed mission of CST-100 has slipped almost a year.Ouch...Clearly, the Boeing way of doing things is not as beatific as some had claimed here.Nor is cheap points scoring welcome here.I was voicing my opinion. Which, in case you had failed to notice, is not prohibited in a discussion thread. And yeah, I was taking it out on those members here proclaiming "The Boeing way is better than the SpaceX way!". And yeah, you will also find posts here were I'm taking it out on members proclaiming "SpaceX is better than Boeing!" But again: you failed to notice this.But I digress.
Even before Tuesday’s announcement, Boeing officials signaled that engineering challenges—particularly the crucial test of the crew emergency escape system—could upset flight schedules. The test escape system is vital for the project, because it is the only way astronauts can survive a rocket failure from before launch all the way to cutoff of the main engine during ascent. NASA has to sign off on the test results before crew transportation can begin.Chris Ferguson, Boeing’s deputy program manager, told a space conference in Long Beach last month that a so-called emergency pad abort test, which blasts a stationary capsule off the launch pad, was slated for late 2017. But he said Boeing intended to use simulations to demonstrate that the emergency escape system will work later in the mission, when the rocket is climbing toward orbit.“We’re pedaling as quickly as we can,” Mr, Ferguson told the conference, calling it “a very aggressive schedule.” He also said “we’ll fly when we’re ready.” If it ultimately “takes a couple of extra months” to certify a safe vehicle, he added, “then we’ll do just that” because “that’s what the country wants, and specifically what the astronauts want.”
So now that the original engineering has proven so deficient, will there be a required in-flight abort?
In the new configuration, the launch escape thrusters are inside of the skirt, it appears.How that is going to relieve over-pressure on the Centaur? Seems like it would amplify it.
Quote from: AncientU on 10/14/2016 12:55 pmIn the new configuration, the launch escape thrusters are inside of the skirt, it appears.How that is going to relieve over-pressure on the Centaur? Seems like it would amplify it.By the time the launch escape thrusters activate, you would have stopped caring about the performance or survival of the Centaur stage, because the survival of the crew is at stake.
Quote from: AncientU on 10/14/2016 11:12 amSo now that the original engineering has proven so deficient, will there be a required in-flight abort? How is the "original engineering" been "has proven so deficient"? ...
Quote from: rocx on 10/14/2016 01:52 pmQuote from: AncientU on 10/14/2016 12:55 pmIn the new configuration, the launch escape thrusters are inside of the skirt, it appears.How that is going to relieve over-pressure on the Centaur? Seems like it would amplify it.By the time the launch escape thrusters activate, you would have stopped caring about the performance or survival of the Centaur stage, because the survival of the crew is at stake.If you crush (detonate) the Centaur when the launch abort thrusters lite off, you could damage the thrusters, nozzles, or the heat shield (as discussed by a former head of engineering at ULA, moments before getting fired). Maybe escape would still be successful; their in-flight demo will confirm... oh wait, they aren't doing an in-flight demo.
Quote from: AncientU on 10/14/2016 11:12 amSo now that the original engineering has proven so deficient, will there be a required in-flight abort? How is the "original engineering" been "has proven so deficient"?
The escape thrusters were on the inside in the previous design.
Why is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket?
Quote from: vapour_nudge on 10/14/2016 03:15 pmWhy is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket? Sure, mini-skirts are a well established safety measure
Quote from: mfck on 10/14/2016 03:16 pmQuote from: vapour_nudge on 10/14/2016 03:15 pmWhy is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket? Sure, mini-skirts are a well established safety measureIt doesn't doesn't decrease the reliability or safety of the vehicle.
Quote from: Jim on 10/14/2016 04:20 pmQuote from: mfck on 10/14/2016 03:16 pmQuote from: vapour_nudge on 10/14/2016 03:15 pmWhy is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket? Sure, mini-skirts are a well established safety measureIt doesn't doesn't decrease the reliability or safety of the vehicle.It is installed to increase the vehicle safety to an acceptable level for crew flights.
That skirt somehow reminded me of the Delta II with the original 10 feet diameter fairing in the 1990s (ROSAT was launched on one of those). Certainly not elegant but I think that's not quite that ugly actually.
Quote from: AncientU on 10/14/2016 06:53 pmQuote from: Jim on 10/14/2016 04:20 pmQuote from: mfck on 10/14/2016 03:16 pmQuote from: vapour_nudge on 10/14/2016 03:15 pmWhy is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket? Sure, mini-skirts are a well established safety measureIt doesn't doesn't decrease the reliability or safety of the vehicle.It is installed to increase the vehicle safety to an acceptable level for crew flights.The point is that even if the skirt was not needed for aeroloads, it is benign and passive and doesn't detract the vehicle operation.
Quote from: Jim on 10/14/2016 08:12 pmQuote from: AncientU on 10/14/2016 06:53 pmQuote from: Jim on 10/14/2016 04:20 pmQuote from: mfck on 10/14/2016 03:16 pmQuote from: vapour_nudge on 10/14/2016 03:15 pmWhy is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket? Sure, mini-skirts are a well established safety measureIt doesn't doesn't decrease the reliability or safety of the vehicle.It is installed to increase the vehicle safety to an acceptable level for crew flights.The point is that even if the skirt was not needed for aeroloads, it is benign and passive and doesn't detract the vehicle operation.The point is that it is needed to allow the vehicle to meet minimum safety standards. It therefore is an active, safety-related component that the vehicle cannot fly without.It is not 'making a safe, reliable launch system safer.'
The point is that it is needed to allow the vehicle to meet minimum safety standards. It therefore is an active, safety-related component that the vehicle cannot fly without.It is not 'making a safe, reliable launch system safer.'
The point is, it does not improve safty, it restores it. Maybe.
I've gone on record elsewhere as being quite critical of this whole design, for a lot of reasons,
I think people here are overreacting, its just a simple answer to an engineering issue. No underlying technical issues,
Quote from: Jim on 10/14/2016 02:54 pmQuote from: muomega0 on 10/14/2016 02:23 pm1) Solids and non common configurations 2) economics "10 flights to achieve 100M/ea"3) multiple configurations and testing (expendable and why certify a LV (Atlas with Solids) that will be retired and the new LV with solids (Vulcan V0) will eventually replace the solids, but cannot be reused to reduce costs?)Just stop, this is not a place to preach your crusade. Those have nothing to do with the addition of the skirt.On the positive side, it's his shortest post ever.
Quote from: muomega0 on 10/14/2016 02:23 pm1) Solids and non common configurations 2) economics "10 flights to achieve 100M/ea"3) multiple configurations and testing (expendable and why certify a LV (Atlas with Solids) that will be retired and the new LV with solids (Vulcan V0) will eventually replace the solids, but cannot be reused to reduce costs?)Just stop, this is not a place to preach your crusade. Those have nothing to do with the addition of the skirt.
1) Solids and non common configurations 2) economics "10 flights to achieve 100M/ea"3) multiple configurations and testing (expendable and why certify a LV (Atlas with Solids) that will be retired and the new LV with solids (Vulcan V0) will eventually replace the solids, but cannot be reused to reduce costs?)
The Atlas V stack is and has been demonstrated to be one of the (if not the most) reliable and safe vehicle flying today.
I've gone on record elsewhere as being quite critical of this whole design, for a lot of reasons, but I'll keep it above-board and remain neutral for now.
USAF 45th Space Wing Study released in 2009 concluded that the Ares I capsule will not survive an abort between MET's of ~30 and 60 seconds. Another conclusion is that it re-affirmed the predictive codes of the 1980s, where, to increase performance, solids were added to Titan. Days after ESAS, and confirmed here, for example, about a year later Ares could not do the job because of LAS mass. What are the range of times being studied for the destruct button in this 422 configuration?That is why when Musk revisted Titan I with only one engine type, those who, even serendipitously, knew history, understood its merits.
Quote from: muomega0 on 10/15/2016 02:11 pmUSAF 45th Space Wing Study released in 2009 concluded that the Ares I capsule will not survive an abort between MET's of ~30 and 60 seconds. Another conclusion is that it re-affirmed the predictive codes of the 1980s, where, to increase performance, solids were added to Titan. Days after ESAS, and confirmed here, for example, about a year later Ares could not do the job because of LAS mass. What are the range of times being studied for the destruct button in this 422 configuration?That is why when Musk revisted Titan I with only one engine type, those who, even serendipitously, knew history, understood its merits.More mumble jumble nonsense and linking to your own postsThe Ares I study has nothing do with this vehicle.
Conclusions a) Re-Confirm Codes. Re-confirm predictive codes & values for solid propellant motor fragmentation, comparing results of the late-1980's joint NASA/DOE/INSRP Explosion Working Group (and related) analyses of solid propellant rocket debris (particularly applied to the Titan and NASA SRB's), and verifying that code accuracy continues into the later 1998 Titan A20 destruct at MET=40s.
The code using Titan Data was applied to Ares I. Could it also be applied to Atlas?
Why did the US adopt a space policy to prevent Atlas/Delta from launching crew? Besides being a convenient way to maintain excess, expensive launch capacity, did anyone think that solids and crew would not be mixed in the future rockets? Since Earth departure is a very small part of LOC....perhaps yes.
NASA will development Crew LV derived from Space Shuttle solid boosters 20 to 30 mT class
Quote from: muomega0 on 10/15/2016 02:11 pmWhy did the US adopt a space policy to prevent Atlas/Delta from launching crew? Besides being a convenient way to maintain excess, expensive launch capacity, did anyone think that solids and crew would not be mixed in the future rockets? Since Earth departure is a very small part of LOC....perhaps yes.USAF 45th Space Wing Study released in 2009 concluded that the Ares I capsule will not survive an abort between MET's of ~30 and 60 seconds. Another conclusion is that it re-affirmed the predictive codes of the 1980s, where, to increase performance, solids were added to Titan. Days after ESAS, and confirmed here, for example, about a year later Ares could not do the job because of LAS mass. What are the range of times being studied for the destruct button in this 422 configuration?That is why when Musk revisted Titan I with only one engine type, those who, even serendipitously, knew history, understood its merits.I left the linked portion of that quote because it is relevant as seen below. QuoteNASA will development Crew LV derived from Space Shuttle solid boosters 20 to 30 mT classSo no, there appeared to be no intent to separate crew and solids.
Why did the US adopt a space policy to prevent Atlas/Delta from launching crew? Besides being a convenient way to maintain excess, expensive launch capacity, did anyone think that solids and crew would not be mixed in the future rockets? Since Earth departure is a very small part of LOC....perhaps yes.USAF 45th Space Wing Study released in 2009 concluded that the Ares I capsule will not survive an abort between MET's of ~30 and 60 seconds. Another conclusion is that it re-affirmed the predictive codes of the 1980s, where, to increase performance, solids were added to Titan. Days after ESAS, and confirmed here, for example, about a year later Ares could not do the job because of LAS mass. What are the range of times being studied for the destruct button in this 422 configuration?That is why when Musk revisted Titan I with only one engine type, those who, even serendipitously, knew history, understood its merits.
Recognizing the schedule burdens placed on unmanned payloads launched using human rated systems, we understand that the DOD and NASA believe that separating human rated space exploration from unmanned payload launch will best achieve reliable and affordable assured access to space while maintaining our industrial base in both liquid and solid propulsion launch systems.2. NASA will development Crew LV derived from Space Shuttle solid boosters 20 to 30 mT class
2004SpacePolicy
- Falcon likely will show that common configurations without 3 engine product lines and no solids is one affordable and reliable way to fly Class A cargo and Crew...
c) Ares I could not loft crew safely, so much for Crew LV with shuttle solids.. so how about that 422/CST-100?Yes less energy in the Atlas solids creates a smaller debris field volume but really the same physics (F=ma include drag, etc) ....at what time can they explode wrt chute deployment?
As for making the LV safer, the mini skirt reduces loads on the Centaur making the LV safer when this particular payload is launched. You must expect changed conditions if you do away with the fairing. What would you expect?
Quote from: vapour_nudge on 10/16/2016 06:14 amAs for making the LV safer, the mini skirt reduces loads on the Centaur making the LV safer when this particular payload is launched. You must expect changed conditions if you do away with the fairing. What would you expect?In my view, a better solution would have been to properly position the payload to begin with, allowing a longer tapered fairing (or whatever solution solved the problem) that would have prevented the aero-loading in the first place. This aeroskirt is a tacked-on fix to save schedule (re-positioning the payload would have meant rebuilding the service tower and redesigning umbilicals) for a problem that shouldn't even exist. - Ed Kyle
Is there an extra separation event for the skirt, or was there going to be something similar anyway for some other fairing/adapter?
Quote from: edkyle99 on 10/16/2016 02:35 pmIn my view, a better solution would have been to properly position the payload to begin with, allowing a longer tapered fairing (or whatever solution solved the problem) that would have prevented the aero-loading in the first place. This aeroskirt is a tacked-on fix to save schedule (re-positioning the payload would have meant rebuilding the service tower and redesigning umbilicals) for a problem that shouldn't even exist. - Ed KylePardon me? Should not exist? This little problem with CST-100 is not the first time (and IMO it will not be the last either) that a given stack-design turns out to have aero-acoustic trouble identified late in the game.
In my view, a better solution would have been to properly position the payload to begin with, allowing a longer tapered fairing (or whatever solution solved the problem) that would have prevented the aero-loading in the first place. This aeroskirt is a tacked-on fix to save schedule (re-positioning the payload would have meant rebuilding the service tower and redesigning umbilicals) for a problem that shouldn't even exist. - Ed Kyle
there are some with Orion
Quote from: Jim on 10/16/2016 08:19 pmthere are some with OrionOrion itself, with the SM fairings, changes in SM design, etc, but I don't think that SLS itself has seen substantial changes - at least not visible hardware changes. - Ed Kyle
You're looking at the difference between designing a spacecraft to go on top of a pre-existing launch vehicle design that is outside of the original use concept vs contemporaneous spacecraft and launch vehicle design.
Quote from: SWGlassPit on 10/17/2016 02:52 pmYou're looking at the difference between designing a spacecraft to go on top of a pre-existing launch vehicle design that is outside of the original use concept vs contemporaneous spacecraft and launch vehicle design.My question is, why did the original design of CST-100 with the stumpy adapter pass muster? They wind tunnel tested it some time back and it was made the baseline design. What changed, and why? - Ed Kyle
My question is, why did the original design of CST-100 with the stumpy adapter pass muster? They wind tunnel tested it some time back and it was made the baseline design. What changed, and why?
Quote from: edkyle99 on 10/17/2016 06:21 pmQuote from: SWGlassPit on 10/17/2016 02:52 pmYou're looking at the difference between designing a spacecraft to go on top of a pre-existing launch vehicle design that is outside of the original use concept vs contemporaneous spacecraft and launch vehicle design.My question is, why did the original design of CST-100 with the stumpy adapter pass muster? They wind tunnel tested it some time back and it was made the baseline design. What changed, and why? - Ed KyleWe don't know if it passed muster. Nothing could have changed, just more testing was done
Mass issues are common in aerospace. Even Shuttle had them. When you design a new vehicle from the ground up, you estimate as best you can, and you include a growth allowance to account for things you haven't designed yet. You design a big-picture concept, you do some analysis, you refine details, you do more analysis, you add more detailed design, lather, rinse, repeat.The problem is that every little screw, every little threaded insert, every inch of wire, every wire clip, every thousandth of an inch of wall thickness has mass, and it all adds up. Now, were your estimates three years ago good enough? Was your mass growth allowance enough? What if you identified a problem late in the game that required a redesign? Is it mass neutral?Don't forget also that you have to make design trades throughout the development life cycle. A big one fighting against mass is cost. Lighter weight components are more expensive to design. They are more expensive to analyze. They are more expensive to manufacture. Decisions have to be made based on these mass-cost trades, but the information you have early in the design stage is different from the information you have later on, so which fixed budget do you blow, your fiscal budget or your mass budget?
Mass issues are common in aerospace. Even Shuttle had them. When you design a new vehicle from the ground up, you estimate as best you can, and you include a growth allowance to account for things you haven't designed yet. You design a big-picture concept, you do some analysis, you refine details, you do more analysis, you add more detailed design, lather, rinse, repeat.The problem is that every little screw, every little threaded insert, every inch of wire, every wire clip, every thousandth of an inch of wall thickness has mass, and it all adds up. Now, were your estimates three years ago good enough? Was your mass growth allowance enough? What if you identified a problem late in the game that required a redesign? Is it mass neutral?
We all know this (or most of us do) - but this is why you always design with mass margins. Clearly something out of the ordinary must have happened here to require *two* solid boosters instead of zero.And those added booster's aren't "free", they do add to the launch cost and decrease the safety by some amount. Boeing seems happy with the tradeoffs, it seems.
I can't remember CST ever being "officially" on Atlas 401/402. When those concepts were going around, they were also circulating artwork with CST on Delta IV M+ and Falcon 9.I think CST was on 412 when the ULA/Boeing partnership was formalized, and the switch to 422 came not long afterwards.
Quote from: arachnitect on 10/19/2016 01:29 amI can't remember CST ever being "officially" on Atlas 401/402. When those concepts were going around, they were also circulating artwork with CST on Delta IV M+ and Falcon 9.I think CST was on 412 when the ULA/Boeing partnership was formalized, and the switch to 422 came not long afterwards.From the complete opposite perspective, perhaps that played a big part in the choice of the Atlas. If they went with the F9, they can't increase mass past a point. You can add an extra solid or even two to a 412 & get a 422 or 432.
The Atlas V rocket currently uses the Common Centaur variant.[10] In 2014, on the NROL-35 mission, Atlas V's Common Centaur first flew in a reengined configuration with an RL10-C-1 replacing its previous RL10-A-4-2. This engine is meant to be common between Centaur and the Delta Cryogenic Second Stage to reduce costs.[11][12] RL10-A-4-2 will continue to be used on some future flights. Atlas V launches using the Dual Engine Centaur configuration must use RL10-A-4-2 because the new engine is too wide to accommodate two side-by-side.[12] To date, all Atlas V launches have used the Single Engine Centaur variant, however CST-100 Starliner and Dream Chaser missions will require the dual engine variant, because it allows a "flatter" trajectory safer for aborts.As on Titan-Centaur, Atlas V 500 launches encapsulate the upper stage inside the payload fairing, to reduce aerodynamic loads. Atlas V 400 flights carry the fairing on top of Centaur, exposing it to the air.
The two engine Centaur first flew in 2014. All previous launches were the single engine variant.
Quote from: muomega0 on 10/19/2016 02:28 pmThe two engine Centaur first flew in 2014. All previous launches were the single engine variant.Incorrect. The majority of Centaurs were two engine flights, starting all the way back in the 60s. The single engine model first flew on Atlas III, in 2000 (?). If you are talking about Atlas V Centaurs, all have been single engine.
Quote from: muomega0 on 10/19/2016 02:28 pmThe two engine {Atlas V reengined} Centaur first flew in 2014. All previous {Atlas V }launches were the single engine variant.Quote from: centaurwikiThe Atlas V rocket currently uses the Common Centaur variant.[10] In 2014, on the NROL-35 mission, Atlas V's Common Centaur first flew in a reengined configuration with an RL10-C-1 replacing its previous RL10-A-4-2. This engine is meant to be common between Centaur and the Delta Cryogenic Second Stage to reduce costs.[11][12] RL10-A-4-2 will continue to be used on some future flights. Atlas V launches using the Dual Engine Centaur configuration must use RL10-A-4-2 because the new engine is too wide to accommodate two side-by-side.[12] To date, all Atlas V launches have used the Single Engine Centaur variant, however CST-100 Starliner and Dream Chaser missions will require the dual engine variant, because it allows a "flatter" trajectory safer for aborts.As on Titan-Centaur, Atlas V 500 launches encapsulate the upper stage inside the payload fairing, to reduce aerodynamic loads. Atlas V 400 flights carry the fairing on top of Centaur, exposing it to the air.NASA gets shuttle derived SLS and the to be retired Atlas....Wrong like most of your postsAtlas V has yet to fly dual engines. The Common Centaur variant is a single engine. All Atlas Centaurs, Atlas I's and Atlas II's had dual engines. The single engine Centaurs were introduced during Atlas III flights and all Atlas V's are single engine to this point.And NASA does not get Atlas
The two engine {Atlas V reengined} Centaur first flew in 2014. All previous {Atlas V }launches were the single engine variant.Quote from: centaurwikiThe Atlas V rocket currently uses the Common Centaur variant.[10] In 2014, on the NROL-35 mission, Atlas V's Common Centaur first flew in a reengined configuration with an RL10-C-1 replacing its previous RL10-A-4-2. This engine is meant to be common between Centaur and the Delta Cryogenic Second Stage to reduce costs.[11][12] RL10-A-4-2 will continue to be used on some future flights. Atlas V launches using the Dual Engine Centaur configuration must use RL10-A-4-2 because the new engine is too wide to accommodate two side-by-side.[12] To date, all Atlas V launches have used the Single Engine Centaur variant, however CST-100 Starliner and Dream Chaser missions will require the dual engine variant, because it allows a "flatter" trajectory safer for aborts.As on Titan-Centaur, Atlas V 500 launches encapsulate the upper stage inside the payload fairing, to reduce aerodynamic loads. Atlas V 400 flights carry the fairing on top of Centaur, exposing it to the air.NASA gets shuttle derived SLS and the to be retired Atlas....
Atlas V has yet to fly dual engines. Got it. That's not a good thing, right? When was the last time any dual engine Atlas flew?True..NASA does not *get* Atlas (nor Vulcan) mixing solids and crew....The reason is that it would require a substantial number of flights to test all the possible flight conditions and its not worth the effort given that LOC is so small during ascent *and* the LV will be retired. Simply redesign Vulcan v0 without solids and start on the path towards reuse, and only certify Vulcan, not Atlas. My guess is that ULA would jump at the chance.., no? Oh..I see now...Vulcan has to have solids so it 'looks like' Atlas. Bravo. BTW. Corrections always welcome....
Hardware! Structural test article for #Starliner #Atlas LV adapter
QuoteHardware! Structural test article for #Starliner #Atlas LV adapterhttps://twitter.com/torybruno/status/861615045729439744
Great hardware designed by @ulalaunch engineer Ed Walton and built by our excellent Decatur facility! CC: @barbegan13
I wonder why the Atlas V lifting the Starliner is called the 422 variant, since it doesn't use any payload fairing. Wouldn't be Atlas V 022 more appropriate in this case?
Quote from: starbase on 05/29/2017 01:31 pmI wonder why the Atlas V lifting the Starliner is called the 422 variant, since it doesn't use any payload fairing. Wouldn't be Atlas V 022 more appropriate in this case?5XX means fairing that encapsulates the whole centaur, 4XX means fairing on top centaur, exposing Centaur.In the Starliner configurtion, the Centaur is not inside a failring, so 4XX.
@BonhommeJerome @KSpaceAcademy Starliner is N22. No fairing, 2 solids, 2 RL10s. To launch crew, no fairing for safety/abort
Any update on when ULA will fly the first dual engine Centaur on Atlas V?
Right, I got the picture. However, according to ULA the first digit refers to the fairing diameter, not if the Centaur is encapsulated or not (which is a natural byproduct of the fairing variant used of course). So if they use no fairing at all it's kind of misleading to designate the variant 422 imho.
5XX means fairing that encapsulates the whole centaur, 4XX means fairing on top centaur, exposing Centaur.In the Starliner configurtion, the Centaur is not inside a failring, so 4XX.
Quote from: hkultala on 05/29/2017 01:43 pm5XX means fairing that encapsulates the whole centaur, 4XX means fairing on top centaur, exposing Centaur.In the Starliner configurtion, the Centaur is not inside a failring, so 4XX.Nope. There used to be an Atlas V 300 configuration as well (would've been used both for narrow payloads on Atlas V-Centaur, and all payloads for Atlas V Lite (Atlas V-Agena 2000). 400/500 just means the fairing diameter
There definitely WAS an Atlas V 300. Specific reference to it exists in several regulatory and development documents. It wasn't abandoned until sometime after 2000, the last document I can find that mentions it is https://www.faa.gov/about/office_org/headquarters_offices/ast/licenses_permits/media/eelvSEis.pdf and thats after the Atlas V name was finalized. As best as I can tell, CUS was still planned to use RL10E-1 up until very shortly before the name change to Atlas V as well.
That's interesting, because when Lockheed ceded the small payload market to Delta II (mostly NASA missions segment) the plan was to just use the 401 for the GPS, DMSP, and DSCS, and other MLV-II class payloads.
Now I'm wondering if Lockheed ever used the 300 naming convention, or just the government.
Tory Bruno Verified account @torybruno 26m26 minutes agoVery exciting! Mighty #Atlas Booster for OFT, the first #Starliner test flight, (uncrewed). @BoeingDefense #LaunchAmerica #Boeing
I asked this in the ULA thread, but perhaps it is more applicable here. Are there flight requirements for the DEC before they will put people on the rocket? And do we know when the DEC will first fly?These requirements and difference across manufacturers are interesting. SpaceX is allowed their single 10x more powerful upper stage engine, but they seem to be required to do more testing of the final configuration than ULA despite ULA adding a whole engine to the design. Any input into the reasoning behind these requirements would be appreciated.
Quote from: intrepidpursuit on 05/10/2018 11:57 pmI asked this in the ULA thread, but perhaps it is more applicable here. Are there flight requirements for the DEC before they will put people on the rocket? And do we know when the DEC will first fly?These requirements and difference across manufacturers are interesting. SpaceX is allowed their single 10x more powerful upper stage engine, but they seem to be required to do more testing of the final configuration than ULA despite ULA adding a whole engine to the design. Any input into the reasoning behind these requirements would be appreciated.The DEC doesn't use two engines for safety - Two engines are needed for the required thrust. CST-100's will be heavy payloads for Atlas V, and they will also fly a different trajectory that requires more thrust.
EDS has been present on all Atlas launches for a while now.
Quote from: brickmack on 05/13/2018 10:11 pmEDS has been present on all Atlas launches for a while now.Incorrect. I suspect you may be confusing this with the Fault Termination System (FTS) that destructs the stack if a problem. EDS is not complete and will fly on OFT for the first time, but disabled.
Quote from: erioladastra on 05/22/2018 05:28 pmQuote from: brickmack on 05/13/2018 10:11 pmEDS has been present on all Atlas launches for a while now.Incorrect. I suspect you may be confusing this with the Fault Termination System (FTS) that destructs the stack if a problem. EDS is not complete and will fly on OFT for the first time, but disabled.It will fly on OFT enabled, but without command authority to activate the escape system.
Will the Boeing Starliner ultimately be launched on the Vulcan Centaur?Thank you.
the Russian engine issue was only relevant to national security launches for obvious reasons. Otherwise, you don't hear anyone saying anything bad about the RD-180. It's record is incredibly good.
Quote from: TJL on 08/24/2020 01:46 pmWill the Boeing Starliner ultimately be launched on the Vulcan Centaur?Thank you.If the Starliner program lasts long enough, it will have to fly on something besides Atlas 5 because there won't be an Atlas 5 in a few more years. I think the RD-180s will run out in four or five years at current launch rates. [...] Atlas 5 could end its service with an occasional Starliner launch until that program ends. - Ed Kyle
Quote from: Ike17055 on 08/24/2020 04:24 pmthe Russian engine issue was only relevant to national security launches for obvious reasons. Otherwise, you don't hear anyone saying anything bad about the RD-180. It's record is incredibly good. That's only because it's an incredibly good engine designed and built by incredibly good people. I'm just talking about politics. Personally, I appreciate the fact that the Russians have routinely kept parts of our space program going more than one time while we screwed around for a decade, trying to find a path. But making a big deal about American manned access to space while using a Russian powered vehicle to get there just seems a little off to me.
Cross-post re: Atlas V/StarlinerQuote from: Nomadd on 08/24/2020 10:23 pmQuote from: Ike17055 on 08/24/2020 04:24 pmthe Russian engine issue was only relevant to national security launches for obvious reasons. Otherwise, you don't hear anyone saying anything bad about the RD-180. It's record is incredibly good. That's only because it's an incredibly good engine designed and built by incredibly good people. I'm just talking about politics. Personally, I appreciate the fact that the Russians have routinely kept parts of our space program going more than one time while we screwed around for a decade, trying to find a path. But making a big deal about American manned access to space while using a Russian powered vehicle to get there just seems a little off to me.Makes sense IF one chooses the point of view considering NPO Energomash as just another subcontractor?
Quote from: edkyle99 on 08/25/2020 01:57 amQuote from: TJL on 08/24/2020 01:46 pmWill the Boeing Starliner ultimately be launched on the Vulcan Centaur?Thank you.If the Starliner program lasts long enough, it will have to fly on something besides Atlas 5 because there won't be an Atlas 5 in a few more years. I think the RD-180s will run out in four or five years at current launch rates. [...] Atlas 5 could end its service with an occasional Starliner launch until that program ends. - Ed KyleULA and NASA are in no rush to human rate Vulcan/Centaur for Starliner. According to Tory Bruno, Starliner might fly on Atlas V for another 7 years:Boeing hasn’t been certifying the Starliner capsule to fly on Vulcan, meaning the Atlas V will remain Starliner’s ride to the ISS for the foreseeable future. ULA will have the RD-180s to handle the expected pace of Starliner launches into 2028, if needed, Bruno said.https://www.bizjournals.com/denver/news/2020/08/20/united-launch-alliance-space-force-spacex-contract.htmlLong-term plan is to human rate Vulcan/ACES:https://twitter.com/torybruno/status/770579558726668288
Quote from: hoku on 08/25/2020 06:23 amQuote from: edkyle99 on 08/25/2020 01:57 amQuote from: TJL on 08/24/2020 01:46 pmWill the Boeing Starliner ultimately be launched on the Vulcan Centaur?Thank you.If the Starliner program lasts long enough, it will have to fly on something besides Atlas 5 because there won't be an Atlas 5 in a few more years. I think the RD-180s will run out in four or five years at current launch rates. [...] Atlas 5 could end its service with an occasional Starliner launch until that program ends. - Ed KyleULA and NASA are in no rush to human rate Vulcan/Centaur for Starliner. According to Tory Bruno, Starliner might fly on Atlas V for another 7 years:Boeing hasn’t been certifying the Starliner capsule to fly on Vulcan, meaning the Atlas V will remain Starliner’s ride to the ISS for the foreseeable future. ULA will have the RD-180s to handle the expected pace of Starliner launches into 2028, if needed, Bruno said.https://www.bizjournals.com/denver/news/2020/08/20/united-launch-alliance-space-force-spacex-contract.htmlLong-term plan is to human rate Vulcan/ACES:https://twitter.com/torybruno/status/770579558726668288Odd: 10 days after Tory tweets that the plan is to human rate Vulcan/ACES Jeff Foust is reporting that ACES is no longer in development.
Quote from: hoku on 08/25/2020 06:23 amLong-term plan is to human rate Vulcan/ACES:https://twitter.com/torybruno/status/770579558726668288Odd: 10 days after Tory tweets that the plan is to human rate Vulcan/ACES Jeff Foust is reporting that ACES is no longer in development.
Long-term plan is to human rate Vulcan/ACES:https://twitter.com/torybruno/status/770579558726668288