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http://www.spaceflightnow.com/news/n1205/09liberty/
ATK unveils proposal it hopes will end NASA's dependence on Russia based on the 154-foot, five-stage booster rocket..motor with an upper stage based on the cryogenic core of Europe's Ariane 5 rocket. .. The capsule would be based on a composite crew module previously developed for NASA, along with a service module that is a scaled-down version of one under development for Orion, and a Max Launch Abort System (MLAS) developed and tested by NASA in 2009. Company officials said that if they receive sufficient funding from NASA's commercial crew program, they could perform the first crewed flight of the system in 2015.
It is about saving jobs....but in this period of history its all about how much does it cost, I will buy it....
More source to this on the cover page at http://www.spacetoday.net/
With this being the show stopper for all commercial efforts that need Nasa funding... http://www.spacenews.com/civil/120514-h … udget.html
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It is about saving jobs....but in this period of history its all about how much does it cost, I will buy it....
That was my first inclination when I heard about Liberty, but then I had a chance to talk with some of their reps at NewSpace and it appears they really are taking an honest stab at commercial crew a la SpaceX/Orbital/Boeing and the others. The only direct commonality between Ares I and Liberty is the solid first stage, which is mainly by virtue of the fact that the 5-stage SRB is already built and tested. It's a new liquid upper stage (evolved from the Ariane 5 Vulcain), new crew capsule, and new launch abort system. The new upper stage and launch abort system system conveniently get rid of the oscillation problems that plagued Ares I.
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The Area 1-X that flew was a 4-segment motor with a dummy mass on board for the 5th segment. I know the solid business, making that 5 segment motor work right without instability or erosive burning will be a challenge. For example, a bit of pressure oscillation can easily feed back into vehicle dynamics, something not seen in static testing on the ground. I heard "thrust oscillations" mentioned multiple times during the Constellation effort.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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The thrust Oscillation was talked about quite a bit when the Ares was still in developement mode under Constellation and was resolved by isolation of the upper stage by shock obsorbers in the interchange section.
gaetanomarano was a strong opponent against the entire using of the SRB...
Ares V (CaLV) - status
The FAST SOLUTION to ALL Ares-1 "VIBRATIONS" problems !!!
The Ares-1 can't fly
Constellation (Cx)
Ares I (CLV) - status
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http://www.nationaldefensemagazine.org/ … Costs.aspx
The Liberty is a rocket being offered by Alliant Tech Systems — better known as ATK — and Astrium, a subsidiary of European defense giant EADS. The Liberty in the near term will compete for a NASA contract to send astronauts to the international space station in low-Earth orbit. Long term, it is looking toward reaching the higher geo-synchronous orbit.
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I thought NASA had already deemed the whole 'liquid second stage on-top of solid first stage' configuration non-viable for any purpose (which is not to say its impossible, just that it would be inferior in cost and safety vs traditional architecture). That whole Obama ostensibly budget-based killing of both the Constellation launch vehicles was effectively allowing NASA and Congress to save-face over the fact they had been betting their whole launch system on a technology that didn't pan out. Private companies are notorious for doggedly sticking with old discarded NASA concepts long after they are obsolete.
Last edited by Impaler (2012-05-14 21:16:10)
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There no technical reason why the Liberty cannot be made to work. Most of our ICBM's for half a century have used solid stages topped with a liquid stage for precise burnout control. Minuteman series and Peacekeeper all work that way.
On the other hand, whether ATK/EADS can compete economically with Spacex depends upon a massive change in corporate vision. It can be done, but few do it. The support per launch has to be trimmed from the population of major city to that of a small town. I include subcontractors and vendors in that assessment.
With its 3 vehicles, Spacex has been establishing a trend of payload cost to LEO vs max payload weight to LEO that is lower than all comers except perhaps ULA's Atlas-5 at its 551/552 configuration only. Maybe. Depends upon exactly how you plot the data.
The way I plot it, ULA Atlas-5 comes off a tad higher than Spacex, and Delta-4 much higher. These are built by giant corporations, used to doing things the NASA way, or at least the DOD way. Both customers are a bit bloated, NASA more so, these later decades.
ATK and EADS fall in that same giant corporation category, used to working on bloated things for government space or defense stuff. If they make the same paradigm shift that Spacex did, they can compete in commercial launch. So could Boeing and Lockheed-Martin, except I really don't see them making that paradigm change, unless forced to do so.
For now, I'd rather see what Spacex can really do, as it will drive paradigm change in its competitors, and break this bloated, expensive impasse we have suffered since the beginning of manned spaceflight.
The Russians did the same launch support model, just within a different economic system: a huge population supported every single launch. That can never be cheap.
Dark horses might include the Skylon thing, or orbital outgrowths of the suborbital spaceplane folks. As organizations, they have the right idea: keep the support team size per launch very small or it'll never be cheap. We'll see.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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Is their even any infrastructure and skill base left to MAKE the solid rocket booster? I don't see why the manufacturer would or even could retain the capability. While Ares I was still on the drawing board their was a point but that's gone now and I think it's only a matter of time until all the shuttle derived concepts are scrapped because of their unsustainable costs, this may simply mean we never see another >100mt Super Heavy and have to work with fully liquid configurations.
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Yes, this is a direct continuation of the Shuttle SRB/Ares I manufacturing capability. Besides, as GW points out solid motors are in fact quite common in defense applications, so ATK is not going away any time soon.
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To answer Impaler's question, yes, Mark is correct. There are several really big solid motor applications active. These include the ICBM's I named, the submarine-launched BM's, and all the big strapons used on both Atlas-5 and Delta-4. ATK and a couple of others build these. My names might be obsolete, but ATK used to be Hercules in Utah. There is also Thiokol in Utah right across the Salt Lake valley from ATK. Plus, UTC-CSD had a big motor operation somewhere near the middle of the Mississippi River.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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ATK Expands Liberty Cargo Capability
Based on NASA’s 15-ft.-dia. Multipurpose Logistics Module for the space shuttle, the Liberty Logistics Module (LLM) will be capable of transporting up to 5,100 lb. of pressurized cargo. Liberty is based on a combination of hardware from NASA’s defunct Constellation program, including the five-segment solid-rocket booster developed for the Ares 1 rocket and a composite space capsule based on the Orion Multipurpose Crew Vehicle. Astrium Space Transportation is providing the Liberty second stage based on the liquid-fueled cryogenic core of the Ariane 5.
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from Spacenut's post no. 4 above:
"The thrust Oscillation was talked about quite a bit when the Ares was still in developement mode under Constellation and was resolved by isolation of the upper stage by shock obsorbers in the interchange section."
Using shock absorbers to attenuate thrust oscillations means the oscillations are still there in the motor, where they really are dangerous, because they are evidence of combustion instability. As I said in some earlier post, the 5-segment design is known to have those problems in horizontal ground tests. It has never flown. This kind of thing can be solved, but my guess is they need to keyhole-slot the propellant grain in the segment closest to the nozzle. That would reduce the peak bore velocity (while preserving burn surface neutrality), which should reduce or possibly even eliminate the tendency to oscillate.
No forward-segment slots, though. That's how they (ATK, formerly Hercules) blew up AFRPL's test stand about 20 years ago. Cost them a billion dollar write-off, it did. They need to talk to their tactical guys about doing a combined thermo-structural / fluid dynamical interior ballistic analysis. Tactical guys do that all the time, the big motor guys do not. But they should. That same kind of inattention to adequate design analysis is what sunk the Titanic.
They don't need that crappy 3-O-ring joint either. That's still a disaster waiting to happen, just like the original 2-O-ring joint was before it (Challenger, 1986). One O-ring will do just fine. If it leak checks OK at 5 psi, it'll hold all the way to case burst. You just need one, and you DO NOT put goo in the insulation joints "upstream" of it: that guarantees an O-ring burn-through (no matter how many you have). The static gas column in the bent space approaching the O-ring is better than any insulator we can build. The only thing you don't want is a straight line-of-sight path for radiant heating from the fire in the motor.
Yeah, it can be solved and made to fly just fine. The tougher problem is corporate cultural change. How do you build it and operate it with a small logistical tail instead of a large one (like the one supporting shuttle SRB's)? That's the real secret to lower launch costs. Spacex is the example that proves it.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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Yes oscillation was mitigated but I think they also did make changes to the number of surfaces in the SRB uping them to allow for a higher nozzle pressure but the long and the short of it are that these are the same casings that have been used for 30 years
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Actually, I'm not too worried about the reuse of old casings. Those are just pieces of steel. I think they're T-250, but it might be something else, similar. As long as they meet dimensional requirements, haven't been overheated, or reached fatigue life, they should be fine. The dimensional requirements are pretty stringent at the sealing surfaces, where the O-rings ride. Those segments will become non-reusable from "dings" hitting the ocean, more than anything else.
Re-insulating the case is not all that big a deal, although in that size, it isn't trivial, either. The insulation is sheets of fiber-reinforced rubber compound wrapped around a bladder inserted into the segment. You pressurize the bladder, which compresses the sheeting against the primed case segment, and you cook it while pressurized to cure the rubber, preferably in vacuum, for best quality control.
Casting propellant isn't all that big a deal, although not trivial in that size. For one thing, it requires a huge mix of propellant. That's a giant facility. OK, there's cast tooling emplaced in the primed/insulated motor case segment to form the finished surface of the propellant. Depending upon the effective viscosity of the propellant (this stuff is thixotropic/non-Newtonian, like concrete, but worse), you gravity or pressure cast this stuff into the segment, under high vacuum. Then you cook it with tooling in place for a few days to cure the propellant. Typical AP-Al-composite, HTPB binder, etc. Just huge.
What baffles me is how they expect to support all of this with a population about the size of a small town instead of the major city they used during shuttle. You have to count all the vendors and subcontractors in that population. Spacex does it mostly in-house, and with a very small population, that's how they do liquid-propellant launch so cheaply. How you do that with giant solids, I'm not so sure, but I am sure that it can be done: because that's what we do making small solid motors for tactical weapons.
GW
"It's all in the cultural change"
Last edited by GW Johnson (2012-07-10 10:11:50)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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So 'Liberty' will now have an STS Solid Rocket booster derived first stage, an Ariane 5 derived second stage, and Orion derived capsule on top of it and an MPLM derived pressurized cargo section, is anyone really buying this farce?
ATK is just trying to pitch NASA a Frankenstein launch vehicle composed entirely of existing parts most of which are from other contractors, half of which aren't even American. Do they really think all these other contractors will just sell them this stuff at marginal cost so they can stick everyone else with the development costs, sure NASA fell for that with the 5 segment Ares I SRB, but I don't think all the rest of these contractors are that dumb. I don't see how ATK could purchase let alone integrate all this stuff into a competitive CCiCap bid, I think their just gambling that a Republican President & Congress will steer business towards them via their DoD connections so long as they can put together a semblance of a vehicle that flies while deliberately low-balling their price quote. Then after the competition is killed off they can have 'unanticipated cost-overruns' till the cows come home which will be blamed on foreign providers justifying yet more money be spent for them to recreate this stuff in house.
Last edited by Impaler (2012-07-11 03:37:53)
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All I can say is that if ATk were to prices its "Frankenstein launch vehicle" below the competitors that it would have all the business that it would want....
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Their competitiveness depends on massive cultural change. I know the crowd at ATK Utah, I used to work with folks from there, being for a while part of the same corporation. That was some time ago, but large corporations change slowly. Back then, I didn't see the capacity for the massive cultural change needed to reduce prices dramatically. Big fat bloated defense contractor. Very typical.
Actually, I didn't see such capacity for cultural change in any of the giant defense contractors, but ULA has proven me wrong. Their Atlas-V is pretty competitive with Spacex's Falcon-9, in spite of being defense conglomerates, which Spacex is not. So it can be done. (One can always argue about how it was done, because things are easy to hide in a giant conglomerate.)
As for the Frankenstein-design of Liberty: there's nothing wrong with using older technologies to do a job, as long as they serve well. There's nothing wrong with bastardizing-together a mish-mosh of things to do a job, as long as it works well. You're corresponding with a guy who would have no qualms at all about pulling a steam locomotive out of mothballs to pull long freights up steep grades faster, or to put sails on ocean-going tankers and freighters to save fuel.
A big solid right off the pad makes a lot of sense, because thrust, not Isp, is the real issue in the first several km going up. Solids do that in spades, and much better than liquids, in part because of the high molecular weight in the exhaust, and in part because the typical throat to casing diameter ratio is just far higher (frontal thrust density achievable). You do have to address extreme reliability if men are to ride, because they cannot be turned off once lit. In that respect, I think the hybrid might be a better deal.
Putting a liquid upper stage on a solid lower stage also makes a lot of sense. This is particularly true if you can generate Isp in the higher range of liquid capabilities, combined with precision thrust control and termination, something solids completely lack. The Ariane upper stage on Liberty has all of these qualities. Restart capability is the most important, personally I don't know if the Ariane stage has that. For Liberty to be really viable, upper stage restart is a critical capability.
That is an awfully long and slender stack, though. There are many possible modes of structural oscillation, most of them dangerous. The most slender vehicles I remember were Scout and Vanguard. They did OK structurally (Vanguard had other problems). Liberty looks worse to me. I think I would have proposed it as a side-by-side cluster of 3 or 4 smaller solids from the strap-on stable, not stretched shuttle SRB technology.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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The Ares 1B makes a lot of sense from a design perspective
I think this is still moving forward under Northern Gruman and would do well with cargo shots to LEO
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Northrop Grumman Innovation Systems is the new owners of what was the ATK version and while its not the headline in this article postin next it is still meantion within it.
NGIS highlights advantages of their Air Force contract win with OmegA
The Omega rocket is meant to be a replacement for the Antares rocket and Delta II.
Meanwhile, ATK (which then became Orbital-ATK and then Northrop Grumman Innovation Systems) had already been working on a heavy-lift solid/liquid propellant rocket with Liberty.
Of course none of this would have happened if we had not seen the RD-180 was from Russia.....
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Thrust oscillations in solids are less objectionable if their thrust contribution is not 100% of first stage/liftoff thrust. Actually, periodic thrust oscillations in a solid are symptomatic of unresolved combustion instability. They interact with mechanical structural oscillation modes in the vehicle, producing (usually) the pogo instability that threatens vehicle breakup.
Pogo can happen without solids, as in Saturn V early on, but solids can be really good at provoking it. That Ares 1 "stick" configuration was really bad for pogo problems, because (1) 100% of the liftoff thrust was solid, (2) it was a long narrow structure subject to pogo, and (3) the stretched 5-segment shuttle SRB design proved to be really hard to tame, as regards combustion instabilities.
This was in spite of being 20% aluminized, which is about the max tolerable metal content. Metals usually help damp the instability tendencies. That kind of periodic thrust oscillation simply wasn't tolerated in tactical solid designs, and we at the plant where I once worked would never let a product like that out the door. Our stuff burned "smooth", only random combustion noise, not organized oscillations.
Aluminized, non-metallized, we just did the job right in development testing and redesign. Expensive up front, but well worth it in the longer run. Part of our better-than-1/million failure rates, sometimes far better.
GW
Last edited by GW Johnson (2018-10-16 14:17:32)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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